Kenton's Blog

Many free, inspection-related videos now available- I'm co-producer of these...

Kenton Shepard (Peak to Prairie Inspection Service) — Wed, 03 Sep 2008 23:43:20 -0500

Although I still perform inspections- mostly high-end homes and expert witness work- a good deal of my time now goes into developing and co-producing educational videos for home inspectors for NACHI.TV. We have about 50 videos available online and about 45 of these are free.

They range in subject from technical subjects for inspectors like mold inspection, inspecting water heaters, photovoltaic systems and crawlspaces to consumer education on infrared cameras, Well and Water Quality, Strawbale home inspection and many more. Please take a few minutes to look over our selection for a few which might interest you!

We now have advanced online courses for continuing education for home inspectors approved in ten states, including (I'm proud to say) my comprehensive Green Building and Log Home Inspection courses. Both are free to the public and relevant to anyone with an interest in these subjects, not just inspectors.

FREE VIDEOS

Drug Detective (Episode 46)
Dan Huber and Nick Gromicko on Marketing (Episode 45)
Inspect4Mold (Canada) (Episode 44)
Inspection Tips and Techniques (Episode 42) (Joe Farsetta)
GutterStuff (Episode 41)
Notching, Holes, & Cutting Inspection (Episode 40)
Drain and Duct Video Inspections (Episode 39)
CH Insurance AD&D Policy FREE to InterNACHI Members (Episode 38)
Staying Focused with NFL Wide Receiver, Mark Jackson (Episode 37)
Home Inspector Pro Website Hosting (Episode 36) (Dominick Maricic)
A Consumer's Guide to Well and Water Quality (Episode 35) (Joe Farsetta)
Marketing Tips with Mike Crow (Episode 34)
Consumer's Guide to Infrared Thermography (Episode 33)
Joe Farsetta on ADRS, CMI, and Education (Episode 32)
Fireplace and Chimney Inspections (Episode 31)
Moisture Free Warranty (Episode 30)
FloodStop (Episode 29)
Highlights from Electrical Inspection Volumes 1-3 (Episode 27)
Law & Disorder Seminar (Episode 26) (Joe Ferry)
US (insurance) Reports (Episode 25)
Search Engine Optimization Tutorial (Episode 24)
FREA (E&O, Liability ins.) (Episode 23)
Infraspection Institute (IR classes)(Episode 22)
Certified NACHI Store (Episode 21) (Paige Peters)
CH Insurance Brokerage (Episode 20)
About Scheduleze (Episode 19)
What's New w/ Home Inspector Pro (Episode 18)
Guardian (Episode 17)
Inspecting a Stairway (Episode 16)
Straw Bale Home Inspection (Episode 15)
Keith Swift Publishing (Episode 14)
Ozone and Mold Eradication (Episode 13)
EPA Green Building Inspection (Episode 12)
Home Inspection Success (Episode 11)
InspectorBoost.com (Episode 10)
Photovoltaic Systems Inspection (Episode 9)
Home Inspector Pro PROMO (Episode 8)
Interview w/ Byron Duerksen (Episode 7)
Certified NACHI Store PROMO (Episode 6)
Episode 5 w/ Kenton Shepard (Episode 5)
Episode 4 w/ Don Kinn (Episode 4)

PAY PER VIEW

Advanced Inspection of Crawlspaces ($34.95)
Introduction to Infrared Thermography Online Video Course ($199.95)
LEED Green Building ($1.99)
Inspecting Water Heater Tanks ($99.95)
Inspecting Means of Egress ($99.95)
Electrical Inspection Volume 3 ($3.99)
Electrical Inspection Volume 2 ($3.99)
Electrical Inspection Volume 1 ($3.99)

Green Commercial Building video

Kenton Shepard (Peak to Prairie Inspection Service) — Fri, 21 Dec 2007 12:42:38 -0600

NACHI TV is producing episodes of various subjects of interest to inspectors. Although they're designed for inspectors, these videos will also be relevant to other real estate professionals and buyers. View episode 12 as we tour this exceptional building and learn about the green design, systems and components which comprise EPA region 8 headquarters in Denver.

This building was built to be green from the ground up, showing the EPA practicing what they preach and incorporating into the design such energy-efficient features such as photovoltaics which convert sunlight directly into electricitry and daylighting systems which bounce natural light deep into the building. From the use of natural, sustainable materials and people-friendly office furniture to the green roofand much more, there's a lot to be learned here. Accompanying us was Jim Bleckledge, project manager for construction.

Photovoltaic System Inspection video: I appear with InterNACHI founder Nick Gromicko

Kenton Shepard (Peak to Prairie Inspection Service) — Fri, 21 Dec 2007 12:17:38 -0600

Photovoltaic (PV) systems are systems which convert sunlight directly into electricity for use an buildings. View this Photovoltaic System Inspection video as InterNACHI founder Nick Gromicko and I accompany Steven Kane of Namaste Solar through the start-to-finish inspection of photovoltaic system. Learn about the different types of systems, their components and what inspectors can and can't inspect.

This video is goes well with the photovoltaic section of my free, comprehensive, online Green Building course, information from which is also available on my website page dedicated to photovoltaic systems.

Strawbale Home Inspection video: I appear with InterNACHI founder Nick Gromicko

Kenton Shepard (Peak to Prairie Inspection Service) — Fri, 21 Dec 2007 12:02:02 -0600

View the Strawbale Home Inspection video as InterNACHI founder Nick Gromicko and I accompany Colorado Straw Bale Association Executive Director Mark Shuenaman and natural plaster contractor Ryan Chivers through two strawbale homes, one under construction so that the bales are visible, and one complete, so that you can see the finished product.

No courses exist to teach home inspectors to inspect strawbale homes. In fact, having finished the free, comprehensive, online Green Building course, I now have a Strawbale Home Inspection course on my list of courses to write which will also be available online.

Until my course is available, this video is one of the few resources available for those interested in strawbale to learn about inspecting them. Those interested in strawbale homes may also find good information on my website page for them, Strawbale Home Basics.

Log Home Inspection video: I appear with InterNACHI founder Nick Gromicko

Kenton Shepard (Peak to Prairie Inspection Service) — Fri, 21 Dec 2007 11:50:06 -0600

View the Log Home Inspection video as InterNACHI founder Nick Gromicko and I inspect a 35 year old log home at 9500 feet in the Colorado Rockies. No courses exist to teach home inspectors to inspect log homes. In fact, having finished the Green Building course, I'm now at work on a comprehensive Log Home Inspection course.

Until my course is available, this video is one of the few resources available for those interested in log homes to learn about inspecting them. Those interested in log homes may also find good information on my website page for them, Log Home Basics.

My new, free, comprehensive Green Building course is now available online!

Kenton Shepard (Peak to Prairie Inspection Service) — Fri, 21 Dec 2007 11:29:15 -0600

After many months of long days and nights of research and writing my Green Building course is finally complete and is available on the website of the International Association of Certified Home Inspectors (InterNACHI). This course is free to the public and can be taken as often as you like. The content is also available on my website to be used as a reference.

The course is designed to educate those wishing to provide neutral third-party verification of green features in homes. For example, it defines "Passive Solar Design" so that no one can claim they have a passive solar design simply because they have windows on the South side of the home. The course typically takes 8-10 hours to complete, not including following the links, which are extensive.

The information available here was pulled together from many sources, spread widely accross the internet and the print media. Some, such as the section on photovoltaic inspections, is the result of my original research. This course is designed for inspectors, but is relevant to anyone involved in real estate and interested in green building. Here is the Table of Contents...

InterNACHI GREEN BUILDING COURSE

ENERGY
1. Report on Energy Status
2. Non-renewable Energy
3. Renewable Energy
CLIMATE CHANGE
1. Climate Change
2. Natural Climate Change
3. Possible Results of Climate change
WATER
1. Groundwater Depletion
2. Water Quality
3. Home Water Treatment
4. Indoor Water Conservation
5. Outdoor Water Conservation
LOT DEVELOPMENT
1. Erosion
2. Landscaping and Grading
BUILDING METHODS
1. Engineered Lumber
2. Value Engineering
3. Enhanced-efficiency Building Methods
4. Strawbale Homes
BUILDING ENVELOPE
1. Climate Zones
2. Insulation
3. Conduction, Convection and Radiation
4. Air Movement in Buildings
5. Attic Ventilation
6. Moisture Control
7. Mold
PASSIVE SOLAR HOMES
1. Passive Solar Home Design
2. Energy-efficient Windows
PHOTOVOLTAIC (PV) SYSTEMS
SOLAR THERMAL (solar water heating)
LIGHTING
1. Lighting: Bulb and Fixture Types
2. Daylighting and Controls
PLUMBING
1. Plumbing Pipes
2. Hydronic Heating
3. Hot Water Recirculation Systems
HVAC
1. Furnaces
2. Air-conditioners
3. Air ducts
4. Evaporative Coolers
5. Humidifiers
6. Heat Pumps
WOOD-BURNING APPLIANCES
1. Wood Stoves
ROOF
1. Roof Defects
2. Green Roofs
INDOOR ENVIRONMENTAL HAZARDS
1. Radon
2. Asbestos
SUSTAINABLE PRACTICES and MATERIALS
1. Sustainability
2. Standards and Certification
ENERGY PROGRAMS AND LEGISLATION
1. Incentives: Renewable-energy/Energy-efficiency
2. Home Energy Audits
3. Home Energy Ratings
4. Energy Codes
5. Green Building Standards
6. Energy (Labeling) Program Comparisons
7. Green Mortgages

Green home inspections

Kenton Shepard (Peak to Prairie Inspection Service) — Thu, 31 May 2007 23:03:32 -0500

I'm considering putting together a home inspection which, in addition to complying with the typical Standards of Practice (NACHI, in my case), would identify green features in the home from a list of about 450. Along with that I'd offer energy rating services. I'm wondering if there's really a market out there for an inspection like this. Does this seem like just a good idea to me, or is it something people will pay for?

AC Date of Manufacture by Serial Number

Kenton Shepard (Peak to Prairie Inspection Service) — Sat, 05 May 2007 14:03:21 -0500

AIR-CONDITIONER DATE CODES (serial #)

AMANA / BLACKHORSEB=1971 or 1981 (Of course, now that they've been bought by Goodman, who knows what'll happen)

BARD1962 to March 1980 Sample Number 123456 A D
1st six digits are the Unit Identity Number. In this example they are represented by the numbers 123456. 7th digit is the month of Manufacture.
8th digit is the year of Manufacture. (The letter D in the Sample represents 1964).

1962 = B 1965 = E 1968 = H 1970 = K 1973 = N Letter "Q" not used 1978 = T

1963 = C 1966 = F Letter "I" not used 1971 = L 1974 = O 1976 = R 1979 = U

1964 = D 1967 = G 1969 = J 1972 = M 1975 = P 1977 = S 1980 = V

April & May 1980 Sample number 123 D A 123456
1st three digits are the Compressor Part Number. 4th digit is the month of Manufacture. 5th digit is the year of Manufacture.
In this sample A represents 1980. 1980 = A 6th thru 11th digits represent the Unit Identity Number.
This serial number style was only used during the months of April & May 1980.

June 1980 to Current Sample number 123 H80 1234567 02 1st three digits = Compressor Part # 4th digit = Month
5th & 6th digits = Year 80 = 1980 81 = 1981 82 = 1982 The year 2000 started the numerical numbering from 00.

00 = 2000 01 = 2001 02 = 2002 Right on through to current date. 7th thru 13th digits = Unit Identity #. 14th & 15th digits = Factory Code (01=OH; 02=GA)

Carrier, Bryant, Payne, Day & NightRecently (last 20 years or so) the first four numbers in the serial number represent the week and year.
Previously, it was a complex series of letters and single digits. Call 905-672-0860 if you get stuck.

ColemanSerial numbers prior to April 1992=1st two numbers are month, then year, then series.
After April 1992, 1st two numbers are year, then month, then series. Call 905-672-0860 if you get stuck.

Comfortmaker (International Comfort)Uses the first letter for the month (skipping I) and the first two digits are the year.

First Company Service PartsIs one of 4 divisions of First Operations. They supply OEM equipment to all of the major HVAC manufacturers.
They are located in Dallas, Tx at 214-388-5751. Harold Hammer at Tech Support (ext#5) will answer your questions.

GoodmanFirst two digits of the serial number are the year. Second two are the month.

Lennox Either the first two or second two digits are the year, it varies by era, but most of them actually have a separate sticker somewhere that has the year printed on it. Newer ones are first two equals manufacturing plant #, 2nd two are year and letter in fifth slot is month.

PeerlessPrior to 1984 there was not a date code included as part of the serial number. Starting in 1984, there was a four digit date code following the serial number that was month and year. Example - JO-12345-1084, this unit was built in October of 1984. Starting in the year 2000, same idea only it was a six digit date code following the serial number that is year and month. Example - 1234567-200105, this would have been build in May of 2001.
Anything without the addition to the serial number would have been made before 1984 and would require contact with the factory.

Rheem & Rudd WeatherkingSomewhere in the middle of the serial number will be a letter. The following four numbers are the week and year.

TRANEUses alpha codes in their serial numbers to determine year of manufacture. They started this in 1987 with the letter B and skipped a couple of letters during the years... The first letter of the serial number gives the year of manufacture as follows:

O, A=80(seventh digit) U=82(seventh digit) X=84 S=86 C=88 E=90 G=92 J=94 L=96 N=1998 R=2000

T=81(seventh digit) W=83 Y=85 B=87 D=89 F=91 H=93 K=95 M=97 P=1999 Z=2001

In 2002 they started their serial numbers with the year it was built. In 2002 the first character of the serial number is 2, in 2003, 3 and so on.

Weil-McLainPlease look on the outside jacket of the boiler for a CP Serial Number. It will have a bar code on it. Call (or email) Weil-McLain and they will tell you the date of manufacture. Phone: 219-879-6561 ask for Technical Services

YORK (Unitary Products since 1984)York purchased Fraser, Johnston and Luxaire in 1980.
Year of make indicated by 3rd letter in the serial number. Note: they skip the letters I, O, Q, U, Z.

1971 - A 1975 - E 1979 - J 1983 - N 1987 - T 1991 - Y 1995 - D 1999 - H 2003 - M
1972 - B 1976 - F 1980 - K 1984 - P 1988 - V 1992 - A 1996 - E 2000 - J 2004 - N
1973 - C 1977 - G 1981 - L 1985 - R 1989 - W 1993 - B 1997 - F 2001 - K 2005 - P
1974 - D 1978 - H 1982 - M 1986 - S 1990 - X 1994 - C 1998 - G 2002 - L 2006 - R

Weatherking: 9th box from left is the year

Furnace Date of Manuufature by Serial Number

Kenton Shepard (Peak to Prairie Inspection Service) — Sat, 05 May 2007 13:19:40 -0500

FURNACE DATE CODES (by serial number)

Rheem & Rudd: in the middle of the serial number will be a letter "F" the following four numbers are the week and year.

Carrier, Bryant, Payne, Day & Night: Recently (last 20 years or so) the first four numbers in the serial number represent the week and year. Previously, it was a complex series of letters and single digits. Call 905 672-0860 if you get stuck.

Lennox: Either the first two or second two digits are the year, it varies by era, but most of them actually have a separate sticker somewhere that has the year printed on it. Newer ones are first two equals manufacturing plant #, 2nd two are year and letter in fifth slot is month (A thru M minus I). So 5898G 07568 would be Plant # 58, Year of MFR would be 98 and month would be July.

Amana: BLACKHORSE. B=1971 or 1981. (Of course, now that they've been bought by Goodman, who knows what'll happen.)

Goodman: First two digits of the serial number are the year. Second two are the month.
Btu rating is model number..ie; GMP075-3 (75,000 bonnet input)
Compressor is same :serial # 9709088872 (yr1997 wk 09) Tonnage is model # CK361C The first two numbers after the CK (letters) divided by 12 is tons. ie: 36 div by 12= 3 tons.

YORK HVAC DATING (Unitary Products since 1984)
Note: they skip the letters I, O, Q, U, Z.
Year of make indicated by 3rd letter in the serial number.

1971 - A 1992 - A
1972 - B 1993 - B
1973 - C 1994 - C
1974 - D 1995 - D
1975 - E 1996 - E
1976 - F 1997 - F
1977 - G 1998 - G
1978 - H 1999 - H
1979 - J 2000 - J
1980 - K 2001 - K
1981 - L 2002 - L
1982 - M 2003-M
1983 - N 2004-N
1984 - P 2005- P
1985 - R
1986 - S
1987 - T
1988 - V
1989 - W
1990 - X
1991 - Y

Water Heater Date of Manufacture by Serial Number

Kenton Shepard (Peak to Prairie Inspection Service) — Sat, 05 May 2007 13:17:52 -0500

WATER HEATER DATE CODES (by serial #)

American

American, Craftmaster, Mor-Flo/American, SABH, US Craftmaster, Ace, American Hardware, Best, Best Deluxe, Apex, Aqua Temp, Aqua Therm, Aquamatic, Champion, De-Limier, Deluxe, Eagle, Earl's Energy Saver, Envirotemp, Four Most, Hotmaster, Hotstream, King-Cleen, King-Line. Master Plumber, Nationaline, Neptune, Penguin, Prestige, Proline, Proline-plus, Quacker, Quick-flo, Raywall, Revere, Riviera, Sands, Sentinal, Service-Star, Shamrock, Special Deluxe, Standard, Super Eagle, Sure-Fire, Thoro-cleamn, True-Test, Tru Value, US Supply, XCL-Energy Saver

2-digit year followed by 2-digit week

9746****** is 46^th week of 1997

A. O Smith

A. O Smith, Glascote, Permaglas

Second letter is the month followed by 2-digit year

A through N is January through December (excluding the letter I)

Bradford-White

Bradford-White, Jetglas

Lochinvar

Lochinvar, Energy Saver, Golden Knight, Knight

First letter is the year, second is the month

A is 1964, 1984 or 2004

Rheem, General Electric

Rheem, Ruud, Rheem/Ruud, Richmond, Vista Therm, Citation, Aqua Therm, Energy Master, Vanguard, Cimmaron, Coast to Coast, Lowes, Servi-star, Tru-value, ABS, Intertherm & Miller, Mainstream, Montogery Ward, Professional.

2-digit month followed by 2-digit year

0794***** is July 1994

State Industries

State, Kenmore, Reliance, Ace , Ambassador, Barnett, Century, Crosley, Energy Stretcher, Freedom, Freedom/Nipsco, Hardware House, Master Plumber/True 5, Mission, Nationaline, Patriot, Penfield, President, Regency, Century, The Plumbery, Thermo-king, TopLine

1-letter month followed by 2-digit year

C05******* is March 2005

Energy Loss through Air Duct Leakage: A Detailed Report

Kenton Shepard (Peak to Prairie Inspection Service) — Sun, 15 Apr 2007 22:29:13 -0500

I understand that this will be more information than many will want to look at, but it's a detailed study with the conclusions explained and the source is very credible.

Air Handler Leakage:
Field Testing Results in Residences

James B. Cummings, Chuck Withers, Janet McIlvaine, Jeff Sonne, Matt Lombardi
Florida Solar Energy Center (FSEC)

FSEC-RR-138-03

Abstract

Testing was performed to characterize air leakage in 30 air handler cabinets and at connections to supply and return ductwork. Operating pressures were measured in the air handler and plenums. Q 0.1 (Q 25) in the air handler averaged 23.9 cubic feet per minute (cfm) (11.3 l/s) in 30 homes. Leakage at the return and supply ductwork connections averaged 3.9 Q 0.1 (1.8 l/s Q 25) and 2.2 Q 0.1 (1.0 l/s Q 25), respectively. Actual return side leakage of 77.5 cfm (36.6 l/s) and supply side leakage of 3.1 cfm (1.5 l/s) are calculated based on Q 0.1 (Q 25) and measured operating pressures, which is 6.4% of the system air flow.

Duct leakage (including the air handler) was also measured in a sub-sample. Return Q 0.1 (Q 25) for 21 homes was 88 cfm (42 l/s). Supply Q 0.1 (Q 25) for 11 homes was 132 cfm (62 l/s). Return leakage is estimated to be 170 cfm (80 l/s) or 13.4% of system air flow and supply leakage is estimated to be 167 cfm (79 l/s) or 13.2% of system air flow.

Background

Considerable research has been performed in recent years investigating the amount of air leakage into and out of duct systems, especially in residences, and rather high levels of duct leakage have been found throughout the United States. In response, a variety of utility and conservation programs have begun to address duct leakage, and home energy rating programs have included duct leakage testing into their protocols. Standards for high efficiency house design and construction in many cases now include duct airtightness as a performance criteria, and as a result, duct systems are becoming more airtight in some new homes. It is not an uncommon occurrence, however, that the ductwork is tight but the overall air distribution system cannot meet the standard because of air handler cabinet leakage. In a sample of 10 houses tested in 1997, duct leakage increased by a factor of 2.7 when only the air handler and grilles were added to complete the system.

Furthermore, considerable debate surrounds the issue of where air handlers should be installed; indoors, outdoors, garage, crawl space, or attic. The last three locations commonly contain air contaminants or excessive heat and humidity which can lead to IAQ, energy, or system performance problems.

Field Study

A study was designed and carried out to determine the amount of air leakage which exists in air handler cabinets as installed in new housing. A sample of 30 houses constructed since January 1, 2001 was selected, with 10 air handlers at each of three locations: indoors, garage, and attic. In addition to leakage in the air handler cabinet, the study also looked at the leakage at the connections of the cabinet to the supply plenum and the return plenum, since these connections would also be located in the zone where the air handler was located.

Key Explanations

In order to assess air leakage at the air handler and two adjacent connections, Q 0.1 (Q 25) was measured at each of these locations.

Note that in this paper, Q 0.1 (Q 25) is total airflow leakage in cubic feet per minute (liters per second in parentheses) when the ductwork or air handler is placed at 0.10 inWG (25 pascals) unless otherwise noted. In the ASHRAE Standard 152P nomenclature, this would be designated as Q 0.1,total (Q 25,total) . When leakage is measured to "out", then it will be listed as Q 0.1,out (Q 25,out) ). While Q 0.1 (Q 25) is the measurement of airflow at a test pressure, it can also be considered to be a measurement of hole size. In order to obtain air leakage as the system is actually operated, it was necessary to also measure the operating pressure differential between inside and outside of the air handler and adjacent connections. In other words, it was necessary to know both the hole size and the operational pressure differential across that hole.

Test Method

The following test method was used for determining Q 0.1 (Q 25) in the AH and at adjacent connections. A segment of the air distribution system (ADS) connected to the air handler was isolated, and a calibrated duct tester was installed onto this segment. Isolating the supply duct from the test segment involved cutting through the main supply plenum (typically foil faced fibrous board), inserting an air barrier through the supply plenum (such as a rigid sheet of plastic), and then sealing this air barrier to the exterior (typically foil) surface of the supply plenum. In this manner, the supply ductwork was removed from the tested segment. (Note, however, that the return side of the system was not removed from the test segment.) In a number of homes, it was not possible to cut through the supply plenum either because there was insufficient length of plenum before branch ducts or because the supply plenum was a flex duct. In these homes, all of the supply registers were sealed, in effect testing the entire duct system.

On the return side, the system normally has one return grille, often located within a few feet of the air handler. The duct tester was attached to the return grille, and the balance of the return grille was masked off.

An airtightness test was performed on the isolated portion of the ADS, obtaining Q 0.1 ((Q 25), total air leakage). Then leaks at the AH-to-supply plenum connection were repaired. The Q 0.1 (Q 25) test was repeated. Then leaks at the AH-to-return plenum connection were repaired. The Q 0.1 (Q 25) test was repeated. Then leaks in the AH cabinet were repaired. The Q 0.1 (Q 25) test was repeated. Leakage at each of the three indicated locations was calculated by subtracting one Q 0.1 (Q 25) value from the preceding Q 0.1 (Q 25) value. A vital factor underlying this method is the ability of the field test staff to eliminate essentially all leakage from the three repaired locations. Considerable attention was given to making sure that these repairs were in fact thorough and complete and were verified by inspection of a second staff member.

One issue that had to be addressed was accuracy of the calibrated blower at very low air flows. The duct test unit that was used has rated accuracy down to 30 cfm (14 l/s). In some cases, the Q 0.1 (Q 25) remaining after repairs was less than 30 cfm (14 l/s). Our response was to calibrate the duct test unit down to 10 cfm (4.7 l/s) against a wind-tunnel with rated accuracy of +1% of reading. We found a rather consistent 2 cfm (1 l/s) offset from reading (the tester was reading high) in the range from 10 cfm (4.7 l/s) to 38 cfm (17.9 l/s). Using this calibration therefore allowed a wider measurement range.

In addition to measuring Q 0.1 (Q 25), "as found" system operating pressures were measured with respect to the zone where the air handler was located. With the system operating, pressure measurements were taken at four areas; 1) the supply plenum to cabinet connection (usually on three sides), 2) in the air handler between the blower and coil (usually at two locations), 3) between the coil and the bottom of the air handler (usually at two locations), and 4) the return plenum-to-cabinet connection (usually at two locations). Note that in all cases, the tested air handlers are "up-flow" and in most cases the blower discharges at the very top of the unit.

Additional Field Data

Based on dimensional measurements and inspections inside the air handler, we knew what portion of the AH is above and below the coil, so that Q 0.1 (Q 25) and pressure measurements could be properly weighted.
Return and supply air flows were measured by means of a flow hood (with rated accuracy of +5% of reading +5 cfm (2.9 l/s) from 0 cfm (0 l/s) to 2500 cfm (1180 l/s)). Air handler flow rates were measured by means of an air handler flow plate device (per ASHRAE Standard 152P methodology; see Palmiter et al., 2000 for description). This calibrated flow plate device, which measures flow by measuring total pressure through a grid, is inserted into the filter access tray near where the return duct connects to the air handler. A manometer measures the pressure differential produced by the air velocity moving across the orifices of the flow device. This pressure differential is converted to an air flow rate for the specific flow plate configuration used. Since the flow plate creates resistance to air flow and therefore modifies the normal air flow rate, a correction factor is assigned by taking into account changes in supply plenum pressure.
The location and type of filter was recorded. (Seven filters were located in the air handler and 23 were at the return grille(s). Filters for all 10attic units were located at the return grille. Note the following relevance: filters located at the return grille cause greater levels of return duct depressurization [and therefore potentially more duct leakage] and fail to filter return leak air.)
The dimensions and the surface area of the air handler cabinet were measured and recorded. (Average air handler surface area was 29.4 square feet (2.73 square meters), ranging from 22.0 square feet (2.04 square meters) to 35.5 square feet (3.30 square meters).)
The fraction of the air handler under negative pressure and under positive pressure was determined by measured dimensions of the air handler cabinet sections. (On average, 6% of the air handler cabinet was under positive pressure and 94% was under negative pressure. 26 of the 30 AHs were 100% depressurized, while four were on average 58% depressurized.)
An estimate was made of the fraction of the initial air handler leak area that was sealed "as found". (19 of the 30 air handlers showed some evidence of sealing. Our evaluation considered "what is the hole size and what portion of that was sealed". On average, 20.4% of air handler leakage had been sealed, based on our visual observation estimates. In one case, 90% was estimated to have been sealed. Therefore, in the absence of air handler cabinet sealing, air handler cabinet leakage would be about 25% greater than what is reported in this paper.)
The types of sealants used at AH connections were recorded. Space conditioning equipment model numbers were recorded.
Rated cooling and heating system capacity was determined.
At 11 of the 30 houses, overall duct system and house airtightness was measured (see section 2.3).

Test Results for 30 Systems

A total of 30 air handlers were tested in 29 houses. (At one house, both an attic and indoor air handler were tested.) Ten air handlers were located in the house, ten were in the garage, and ten were in the attic. All 30 were located in central Florida and were constructed in the year 2001.

The airtightness results from all 30 air handlers are as follows (note that the units for Q 0.1 (Q 25) is cfm (l/s)): 23.9 Q 0.1 (11.3 l/s Q 25) in the air handler cabinet, 3.9 Q 0.1 (1.8 l/s Q 25) at the return connection, and 2.2 Q 0.1 (1.0 l/s Q 25) at the supply connection. These measured leakage amounts were "as found", that is, the leakage of the system was measured without making any changes to the system with one exception. If the filter access door was off or ajar, then it was placed in its proper position. The filter access door was found to be removed or ajar in two homes, both interior air handlers. For reference, Q 0.1 (Q 25) was also measured before adjusting the filter access doors. In one case, a missing filter access door represented 189 Q 0.1 (89 l/s Q 25). In the other case, an ajar filter access door represented 37 Q 0.1 (17 l/s Q 25).

Pressure differentials were measured at four locations under normal system operation, as described earlier. The lower portion of the air handler was always under negative pressure. The upper portion of the handler was under negative pressure in all but four cases (the exceptions were furnaces or hydronic coil units). In those four cases, on average, 42% of the unit was under positive pressure. On average, operating pressures were -0.327 inWG (-81.6 pascals) at the return connection, 0.538 inWG (-134.2 pascals) in the lower portion of the air handler, 0.713 inWG (-177.7 pascals) in the upper portion of the air handler (between the blower and coil) in all but three units, 0.528 inWG (+131.7 pascals) between the blower and supply plenum connection in three units, 0.237 inWG (+59.1 pascals) at the supply connection, and 0.277 inWG (+69.1 pascals) in the supply plenum. The weighted air handler negative pressure zone was 0.627 inWG (-156.3 pascals). (The pressures measured in each region of the system were weighted by the surface area that region represented.)

Based on the measured operational pressures and the Q 0.1 (Q 25) for each location, estimated air leakage has been calculated for both the negative pressure and the positive pressure zones of the "air handler plus", where "air handler plus" means the cabinet plus two plenum connections. The calculation method (Equation 1) comes from ASHRAE Standard 152P.

Q = Q 0.1 (dP actual/0.1) 0.6	Equation 1 (IP)
Q = Q 25 (dP actual/25) 0.6	Equation 1 (SI)

where Q is the duct leakage air flow and dP actual is the operating pressure where the leak is located.

The negative pressure zone (in cabinet and return connection) had an average leakage of 77.5 cfm (36.6 l/s), or 6.1% of the average 1266 cfm (598 l/s) of air handler air flow. The positive pressure zone had an average leakage of 3.1 cfm (1.5 l/s), or 0.25% of air handler flow.

Air Leakage Variations by Air Handler Type and Location

When planning the project, it was intended that six gas furnaces would be tested, two from each air handler location. However, only three furnaces were tested, all in the garage because no furnace units were found in our sample of interior or attic units. In addition to the three furnaces, one hydronic gas heating system was tested (this air handler was also located in the garage). The hydronic system uses a hydronic heating coil with hot water supplied by a gas water heater. The remaining 26 air handlers were heat pumps. Table 1 presents airtightness results by air handler location and fuel type. The three gas furnaces were found to be much more leaky than the non-furnace units; 51.8 Q 0.1 (24.4 l/s Q 25) versus 20.8 Q 0.1 (9.8 l/s Q 25). The hydronic unit had air handler leakage of 31.6 Q 0.1 (14.9 l/s Q 25) closer to the leakage of the standard electric air handlers. When converted to normal operation leakage using Equation 1, the three furnace units experienced 145 cfm (68 l/s)of return leakage and 13 cfm (6 l/s) of supply leakage. By comparison, the 27 non-furnace air handlers experienced 70 cfm (33 l/s) of return leakage and 2 cfm (1 l/s) of supply leakage.

Table 1a (IP)
Operating pressures, Q 0.1, and calculated operational leakage for 27 electric
and 3 gas air handlers (furnaces). Note that "leak cfm" includes leakage in the
air handler cabinet and the return and supply connections to the cabinet.

	dP return connect. (inWG)	dP AH (-) region (inWG)	dP AH (+) region (inWG)	dP supply connect. (inWG)	Q 0.1 ret. Connect (cfm)	Q 0.1 air handler (cfm)	Q 0.1 sup. Connect (cfm)	operation leak (cfm) (-) region	operation leak (cfm) (+) region
Attic	-0.297	-0.552	NA	0.175	0.9	21.3	2.6	61.3	2.4
Garage	-0.459	-0.783	NA	0.264	2.6	20.8	1.6	78.6	2.7
Interior	-0.275	-0.675	NA	0.243	3.5	20.4	1.2	72.8	1.3
Avg. (27 AHs)	-0.331	-0.658	NA	0.223	2.3	20.8	1.8	70.0	2.0
Furnace (3 AHs; all in garage)	-0.293	-0.349	0.482	0.362	18.2	51.8	5.3	144.7	12.7
Avg. (30 AHs)	-0.327	-0.627	0.398	0.237	3.9	23.9	2.2	77.5	3.1

Table 1b (SI)
Operating pressures, Q 25 , and calculated operational leakage for 27 electric
and 3 gas air handlers (furnaces). Note that "leak cfm" includes leakage in the
air handler cabinet and the return and supply connections to the cabinet.

	dP return connect. (pa)	dP AH (-) region (pa)	dP AH (+) region (pa)	dP supply connect. (pa)	Q 25 ret. Connect (l/s)	Q 25 air handler (l/s)	Q 25 sup. Connect (l/s)	operation leak (l/s) (-) region	operation leak (l/s) (+) region
Attic	-74.1	-137.7	NA	43.7	0.4	10.1	1.2	28.9	1.1
Garage	-114.4	-195.1	NA	65.7	1.2	9.8	0.8	37.1	1.3
Interior	-68.6	-168.4	NA	60.5	1.7	9.6	0.6	34.4	0.6
Avg. (27 AHs)	-82.5	-164.0	NA	55.6	1.1	9.8	0.9	33.0	0.9
Furnace (3 AHs; all in garage)	-73.0	-87.0	120.1	90.3	8.6	24.4	2.5	68.3	6.0
Avg. (30 AHs)	-81.6	-156.3	99.1	59.1	1.8	11.3	1.0	36.6	1.5

When gas furnaces are excluded, there were only minor variations in cabinet airtightness by air handler location. Q 0.1 (Q 25) is essentially the same for each air handler location; 21.3 cfm (10.1 l/s) for attic, 20.8 (9.8 l/s) for garage, and 20.4 (9.6 l/s) for indoors. However, there is a noticeable difference in operational leakage because return side pressure is substantially lower for attic installations. While air handler pressure for garage and interior units are 0.674 inWG (-168 pascals) and 0.782 inWG (-195 pascals), respectively, it is 0.554 inWG (-138 pascals) for attic units. As a result, return side leakage for attic units (just air handler cabinet and return connection) is 22% less compared to garage units and 16% less compared to interior units.

While "total" return leakage of the air handler cabinet plus two connections is approximately 20% less for attic units compared to other air handlers, return leakage from outdoors is greater for attic units. That is because the fraction of the return leakage that is "to outdoors" (or in this case to attic) is much higher for attic units. This is documented in the "extended test results" presented in the next section. When the leakage of the entire return system is considered, total return side leakage from "outdoors" is much greater for units located in the attic, because essentially all of the return ductwork (and therefore leakage) of the attic units is in the attic space.

Extended Testing in 11 Houses

In 11 of the 30 houses, additional (extended) testing was performed. This extended testing included measuring the airtightness of the entire duct system (both "total" and "to outdoors") and of the house airtightness, following the test methods of ASHRAE Standard 152P (ASHRAE, 2001). First, the air handler was turned off and masking material was placed over supplies and returns. Second, the ductwork was split (sealed or blocked) at the air handler, either by placing masking over the blower intakes (preferred method) or inserting a barrier into the filter track in the bottom of the air handler. Two duct testers were installed, one at a return register and one at a supply register. With all other registers masked off, both sides of the system were taken to -0.1 inWG (-25 pascals) at the same time. ASHRAE 152P allows both sides of the system to be tested separately. There is benefit, however, to running the test with both sides depressurized simultaneously. When performing the Q 0.1,total (Q 25,total) test (leakage to both indoors and to out), any leakage which might exist across the seal or at fan mounts would be very small, and therefore would have essentially no impact on the test results. Furthermore, any leakage past the seal in the air handler would only "steal" from the leakage of one side of the system and "give" it to the other side of the system. By contrast, if only one side of the system is tested at a time, then there is a 25 pascal pressure differential across the seal in the air handler. Therefore, the measurement error could be substantial, and this error gets added to both sides of the system. This test yielded Q 0.1t,s (Q 25t,s ) and Q 0.1t,r (Q 25t,r), where "t" refers to total leakage (leakage to both indoors and outdoors), "s" refers to supply, and "r" refers to return (Table 2).

The duct airtightness tests were repeated with the house depressurized to the same -0.1 inWG (-25 pascals) as the duct system. This test yields duct leakage to outdoors (Table 2). The test results are Q 0.1o,s (Q 25o,s ) and Q 0.1o,r (Q 25o,r), where "o" refers to leakage to out ("out" defined as outside the conditioned space, including buffer spaces such as attic or garage). By having the house at the same pressure as the duct system, leakage of the ductwork to the house is eliminated.

Some observations can be made from the extended test data in 11 houses. Total leakage on the return side of the system (including the air handler and return connection) was 58 Q 0.1 (27 Q 25). Weighted operating pressure on the return side was measured at 0.401 inWG (-100 pascals) (including both return ducts and air handler), indicating operating return leakage of 106 cfm (50 l/s), or 8.4% of system air flow.

Table 2a (IP)
Extended test results, including total duct leakage (Q 0.1t), duct leakage to
outdoors only (Q 0.1o), and house airtightness (Q 0.2 and ACH 0.2) in 11 houses.

house no.	Q 0.1t,r (cfm)	Q 0.1t,s (cfm)	Q 0.1t (cfm)	Q 0.1o,r (cfm)	Q 0.1o,s (cfm)	Q 0.1o (cfm)	Q 0.2 (cfm)	Q 0.2 sealed (cfm)	ACH 0.2
1	30	98	128	30	48	78	1288	1187	5.33
3	143	308	451	64	154	218	3643	3096	8.81
4	45	116	161	34	81	115	1627	1545	5.91
5	41	115	156	33	57	89	1317	1269	4.51
10	61	189	250	41	129	170	1121	1056	3.72
11	80	141	221	73	73	147	1470	1369	4.58
12	79	161	240	47	67	114	1919	1884	4.90
17	36	146	182	15	1	16	1068	992	4.73
18	64	93	157	19	42	61	1555	1487	9.98
19	42	41	83	4	29	34	3040	2755	6.04
27	20	45	65	17	21	38	1912	1899	4.26
avg.	58	132	190	34	64	98	1814	1685	5.71

Table 2b (SI).
Extended test results, including total duct leakage (Q 25t), duct leakage to
outdoors only (Q 25o), and house airtightness (Q 50 and ACH50) in 11 houses.

house no.	Q 25t,r (l/s)	Q 25t,s (l/s)	Q 25t (l/s)	Q 25o,r (l/s)	Q 25o,s (l/s)	Q 25o (l/s)	Q 50 (l/s)	Q 50 sealed (l/s)	ACH50
1	14	46	60	14	23	37	608	560	5.33
3	67	145	213	30	73	103	1719	1461	8.81
4	21	55	76	16	38	54	768	729	5.91
5	19	54	74	16	27	42	622	599	4.51
10	29	89	118	19	61	80	529	498	3.72
11	38	67	104	34	34	69	694	646	4.58
12	37	76	113	22	32	54	906	889	4.90
17	17	69	86	7	1	8	504	468	4.73
18	30	44	74	9	20	29	734	702	9.98
19	20	19	39	2	14	16	1435	1300	6.04
27	9	21	31	8	10	18	902	896	4.26
avg.	27	62	90	16	30	46	856	795	5.71

Total leakage on the supply side of the system was a very large 132 Q 0.1 (62 Q 25). Operating pressure measurements were taken in the supply plenum but not throughout the supply ductwork. ASHRAE 152P suggests using half of the supply plenum pressure as an estimate of overall supply ductwork operating pressure. For these 11 systems, average supply plenum pressure was 0.30 inWG (74 pascals). Based on a supply pressure of 0.15 inWG (37 pascals), actual leakage would be 167 cfm (79 l/s), or about 13.2% of air handler air flow. (Even if actual supply pressure was lower by factor of two, or 0.074 inWG (18.5 pascals), the resulting operational leakage would be 110 cfm (52 l/s) or 8.7% of air handler flow, which is still large.)

In addition to the extended testing results from these 11 units, return side leakage (including the air handler and return connection) is available for 10 additional systems. Therefore, return side leakage is available for 21 of the 30 systems. Airtightness for this larger sample of 21 was 88 Q 0.1 (42 Q 25), considerably greater than the 58 Q 0.1 (27 Q 25) for the 11 homes. Operational leakage for these 21 systems was found to be 170 cfm (80 l/s; based on Q 0.1 (Q 25) and operational pressure), or 13.4% of system air flow.

Duct Leakage to "Out". In 11 homes, duct leakage to "out" was measured (Table 2). On average, about 50% of the leakage of the return ductwork (including air handler) and supply ductwork was to "out" ("out" defined as outside the conditioned space, including buffer spaces such as attic or garage). The fraction of the leakage that was to "out" varied considerably by air handler location. For attic, 66% of the total leakage was to out. For garage, 53% of the total leakage was to out. For indoor units, 34% of the total leakage was to out. The sample size is small, so the conclusions regarding "leakage to out" must be considered preliminary. The biggest variable seems to be the fraction of the return ductwork that is in the attic, since nearly all of the supply ductwork is in the attic regardless of air handler location. Based on our visual inspections, the fraction of the return ductwork that was in the attic has been estimated; 100.0% for attic air handlers, 44% for garage air handlers, and 21% for indoor air handlers. From a cooling energy point of view, the fact that all return leaks -- whether in the air handler cabinet, the return connection, or the entire return ductwork - of attic systems originate in the attic means that the energy consumption, peak electrical demand, and peak period system performance is much more dramatically impacted for attic air handler systems compared to the others.

In summary, extended testing finds that there is a very substantial duct leakage problem with the new homes that were tested in this study.

System Air Flow Rates

Air flow rates were measured for each system. Using a flow hood, air flow was measured at each supply and each return. Using a flow plate device, the air handler flow rate was measured in 24 of 30 air handlers. In 17 of the 24 cases, the flow plate was installed in the filter tray, the intended location for the flow plate. In 7 of the 24 cases, the flow plate was installed at the single return grille because it could not be placed into the air handler. In the 6 cases where the flow plate measurement was not performed, either there was no access to the filter tray or the flow plate would not fit the air handler dimensions (most often because the filter access at air handler was sealed closed with mastic).

A "best estimate" of total air handler air flow is based on the flow hood at the return(s) and addition of estimated return leakage (including the air handler and connections). (In calibration work, we have found the flow hood used for these measurements to be very accurate when measuring return air flows, while significantly overestimating supply register air flows. For those cases with both flow plate and flow hood measurement at the grille, the average was 1131 cfm (534 l/s) for the flow hood and 1164 cfm (549 l/s) for the flow plate, with the flow plate higher in each case.) Our best estimate of total air handler air flow was 1266 cfm (598 l/s) per system. With average nominal cooling capacity of 38,800 Btu/hr (11.4 kW) per system (ranging from 16,000 (4.7 kW) to 56,000 Btu/hr (16.4 kW)), this converts to 392 cfm per ton (52.5 l/s per kW), or nearly right on target with the nominal 400 cfm per ton (53.6 l/s per kW) normally indicated by manufacturers as design flow.

Return air flow was measured at 1107 cfm (523 l/s), or 159 cfm (75 l/s) less than the total air flow. This 159 cfm (75 l/s), or 12.6% of the return air flow, is return leakage, including return leaks in the air handler, the return connection, and the return ductwork.

House Airtightness

House airtightness was also measured in 11 houses using a blower door (Table 2). On average, house airtightness was found to be 5.7 ACH 0.2 (5.7 ACH50), in line with test results on other samples of homes built in the past decade in Florida.

Since the registers were already masked off to perform the duct airtightness test, the house airtightness test was performed once with all registers masked off and again with all registers open (normal status). The difference between the two tests (registers masked and unmasked) yields a measurement of duct system airtightness. On average, 7.1% of the house envelope leakage was found to be in the duct system. The amount of air leakage into and out of the house through duct leaks is of course proportionally much greater than 7.1%, because most of the ductwork operates under pressures of 0.12 inWG (30 pascals) to 0.48 inWG (120 pascals).

Conclusions

Leakage in the air handler averaged 23.9 Q 0.1 (11.3 l/s Q 25) in 30 homes. Leakage at the return and supply plenum connections averaged 3.9 Q 0.1 (1.8 l/s Q 25) and 2.2 Q 0.1 (1.0 l/s Q 25), respectively. Using the operating pressures in the air handler and at the plenum connections, these Q 0.1 (Q 25) results convert to actual air leakage of 77.5 cfm (36.6 l/s) on the return side (negative pressure side) and 3.1 cfm (1.5 l/s) on the supply side (positive pressure side). The combined return and supply air leakage in the air handler and adjacent connections represents 6.4% of the system air flow. This is a concern when one considers that a 6% return leak from a hot attic (peak conditions; 120 oF (48.9C) and 30% relative humidity) can produce a 23% reduction in cooling output and 31% increase in cooling energy use (Cummings and Tooley, 1989). The total energy, peak demand, and peak system performance consequences are much greater for attic air handler systems since all the return leakage comes from the attic. While houses with air handlers indoors and in garages may have some return ducts in the attic, not all leakage comes from the attic.

Additional conclusions about duct leakage can also be drawn from the extended test results. Return Q 0.1,total (Q 25,total) for 21 homes is 88 cfm (42 l/s). Supply Q 0.1,total (Q 25,total) for 11 homes is 132 cfm (62 l/s). Using measured operating pressure in the return ducts and estimated operating pressure in the supply ducts, return leakage is estimated to be 170 cfm (80 l/s; 13.4% of system air flow) and supply leakage is estimated to be 167 cfm (79 l/s; 13.2% of system air flow). This level of duct leakage continues to be a point of concern.

Acknowledgements

Thanks to the Florida Department of Community Affairs, Brookhaven National Laboratory, and the U.S. Department of Energy for funding to carry out this research, and to U.S. DOE Funded Building America Industrialized Housing Partnership (BAIHP) for additional resources.

References

American Society of Heating, Refrigerating, and Air Conditioning Engineers, ASHRAE Standard 152P-2001, "Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems", January 2001.

Cummings, J. B. and Tooley, J. J., "Infiltration and Pressure Differences Induced by Forced Air Systems in Florida Residences," ASHRAE Transactions, 1989, Vol.95, Part 2.

Palmiter, L. and P.W. Francisco 2000. A New Device for Field Measurement of Air Handler Flows. Proc. ACEEE 2000 Summer Study on Energy Efficiency in Buildings. Washington, D.C.: American Council for an Energy Efficient Economy.

James B. Cummings is Program Director, Chuck Withers is Senior Research Analyst, Janet McIlvaine is Research Analyst, Jeff Sonne is Research Engineer, and Matt Lombardi is Engineering Assistant at the Florida Solar Energy Center in Cocoa Florida.

Cutting Energy Costs Throughout Your Home

Kenton Shepard (Peak to Prairie Inspection Service) — Sun, 15 Apr 2007 20:48:20 -0500

Energy Use For Appliances
Household appliances, including lighting, account for roughly 23 percent of energy consumption in the average Virginia home. Because these appliances are primarily powered by electricity, which is more expensive per unit of energy than other fuels, they comprise a larger share of the average household energy expenditure: roughly 30 percent.
What Can You Do About Your Appliance Energy Use?
There is a lot you can do to control and reduce appliance energy use. If any of your appliances need replacement, you can select more efficient models. Even if your current appliances don't need to be replaced, it might be a good idea to do a little research now so that when they do go, and you have to rush out to buy replacements, you'll know what you want (as you know, appliances usually fail over holiday weekends when the in-laws are visiting!).
If you aren't planning to replace an existing appliance, there are often simple measures that can be taken to improve its energy performance. And, even if your appliances are in perfect working order, adjusting the way you use them can often reduce their energy consumption.
Shopping For New Appliances
Most new appliances tend to be considerably more energy-efficient than their predecessors. Energy efficiency alone is rarely enough justification for replacing an old appliance since the energy savings are typically not great enough to justify the cost of the new appliance. However, there are many reasons people decide to replace an old appliance. It may have stopped working completely or it may simply not look right in a newly remodeled kitchen. Regardless of the reason for buying a new appliance, it almost always pays to buy an energy-efficient model.
One very useful resource is the Consumer Guide to Home Energy Savings, published each year by the American Council for an Energy Efficient Economy (2140 Shattuck Ave. #202, Berkeley, CA 94704).
The EnergyGuide label
One of the most useful tools for shopping for energy-efficient appliances is the EnergyGuide label. Federal law requires that EnergyGuide labels be attached to all new refrigerators, freezers, water heaters, dishwashers, clothes washers, air conditioners, heat pumps, furnaces, and boilers. The following explanation should give you a good idea of exactly what the EnergyGuide labels tell you and how it can help you make an informed decision when shopping for new energy-efficient appliances.
The information provided by EnergyGuide labels varies somewhat with different appliances, so we'll take a look at several different categories of appliances and provide examples of labels.
Refrigerators and freezers
For refrigerators (Figure 1), you will see a large number near the center of the label. This tells you the approximate yearly operating cost for that particular model, and it's the best way to quickly compare one model to another. Keep in mind that all these estimates are based on standardized tests. As with EPA auto mileage ratings, the values are very useful for comparing one model to another, but your real costs may vary.
EnergyGuide labels for freezers are the same as for refrigerators.
1. Top of label: Type of appliance, capacity, model number.

2. The large number tells you the approximate yearly energy cost in dollars. It is based on the average cost of electricity around the country, which changes from year to year.
The labels on different models or even on the same models in different stores may have been printed at different times, so the numbers might be a little different. Also, because your electricity costs are probably different from the national average, this may not tell you how much the refrigerator will cost to operate in your area (see #4, below).

3. This is a scale that shows how the refrigerator compares with other similar models on the market in terms of energy efficiency. The operating costs of the most efficient and least efficient in this size category are shown on the scale. A word of caution: the ranges provided on EnergyGuide labels are not updated regularly and may not be accurate. In other words, even though the scale shows this particular model to be at the high efficiency (low energy cost) end of the scale, the scale itself may have shifted as more efficient models have come onto the market. The best thing to do is to shop around until you are satisfied you are getting the best buy for your money.

4. The yearly energy cost table provides a way for you to figure out how much the refrigerator will cost to operate in your area, based on your electricity rates. To find out how much you pay for electricity, look on your most recent utility bill.
Water heaters
For water heaters, the EnergyGuide label looks just like the label for refrigerators, except that the detailed information provided for determining the actual operating cost is based either on electricity costs or gas costs, depending on the type of water heater. Electricity prices are given in cents per kilowatt-hour and gas prices in cents per therm (100,000 Btu) or cents per ccf (hundred cubic feet) of natural gas.
Water heaters designed for propane should have EnergyGuide labels with energy costs in cents per gallon, although the range may not go as high as your propane cost. If the per-gallon prices listed on the label do not go high enough, divide your actual propane cost by the highest propane cost listed, and multiply the estimated annual cost by that value. Refer to Chapter 6 for more information on water heaters.
Dishwashers and clothes washers
For appliances that use hot water (dishwashers and clothes washers), the labels are a little different. Most of the energy used by these appliances is for heating the water rather than running the appliance itself. Under typical usage patterns, water heating accounts for about 80 percent of the energy use by dishwashers and 90 percent of the energy use by clothes washers. (The rest of the energy is used for pumps, motors, and an electric drying cycle in dishwashers.) So how much money you spend each year for one of these appliances depends on how you heat your water.
The EnergyGuide labels for these appliances, therefore, provide two sets of numbers- one for electric water heating and one for gas water heating (Figure 2).
1. Use this large number to quickly compare the approximate operating costs of different models. If you have an electric water heater, use the number on the left. If you have a gas water heater, use the number on the right.

2. The yearly energy cost tables are more complex with dishwashers and clothes washers, because you need to consider both the energy cost and how you use the appliance (number of loads per week). Find the row corresponding to your energy cost and the vertical column corresponding to your expected use. The intersection is your expected annual cost.
If you have a propane water heater, you will need to calculate your annual operating cost using the natural gas table. One gallon of propane is equivalent in energy content to .93 therms (or ccf) of natural gas. Because a gallon of propane is usually a lot more expensive than a therm of natural gas, the tables on the EnergyGuide label probably do not go high enough. Use the following method to calculate your costs if using a propane water heater:
Divide your cost of propane (per gallon) by the highest cost per therm of natural gas listed, and multiply that value by 1.08 (to account for the greater heat content in natural gas). The resulting number is the factor you should use to calculate your expected annual operating cost. Multiply that factor by the annual operating cost listed on the bottom horizontal line of the EnergyGuide label. For example, using the dishwasher EnergyGuide label in Figure 2, if you pay $1.28 per gallon for propane, divide $1.28 by $.60 and multiply that value by 1.08 ($1.28 ÷ $.60 x 1.08 = 2.3). If you do six loads of dishes per week, your expected annual operating cost would be $97 ($42 x 2.3 = $97).
Room air conditioners
For room air conditioners (air conditioners that are installed either in a window or into an opening in the wall), the EnergyGuide label includes an energy efficiency rating (EER) instead of an annual energy cost number. The EER tells you how efficient the air conditioner is. An average model on the market has an EER between 8-1/2 and 9-1/2, while the most efficient models have EERs as high as 12.
1. The large number is the Energy Efficiency Rating, which is the ratio of cooling output (in Btu) divided by the power consumption (in watt-hours). The higher the number, the more efficient the air conditioner.

2. The yearly operating cost table factors in both your cost of electricity (horizontal rows) and your expected hourly use of the air conditioner (vertical columns). In the mountainous parts of the Commonwealth you can expect to use an air conditioner for as little as 350 hours per year, While along the border near North Carolina, up to 1000 hours of operation can be expected.
Choosing And Using Appliances
On the following pages, each of the major home appliances are covered in detail, listing considerations for selection of new equipment, suggestions for improving the efficiency of older models, and tips on how to use the equipment for maximum energy performance.
Refrigerators and freezers
If your old refrigerator was purchased before 1975, it probably consumes at least twice as much electricity as an energy-efficient new model.
Even though federal law mandates relatively stringent energy standards for new refrigerators, there is still considerable difference between the most and least efficient models in a given size category. Always compare the EnergyGuide labels.
When looking for a new refrigerator or freezer, also consider these points:
· Avoid convenience features that you don't really need. In most cases, through-the-door ice dispensers and water dispensers increase energy use.
· Most new refrigerators have heating elements built into the wall of the refrigerator that help prevent condensation from forming. This feature is often not needed and wastes energy if not turned off. Choose a model that has a power-saver or energy-saver switch to turn off these heating coils when not needed.
· With freezers, manual defrost models are considerably more energy efficient than frost-free models - this difference in efficiency will be reflected on the Energy-Guide labels.
Installation of refrigerators and freezers
You will achieve better energy performance from a refrigerator or freezer by following the recommendations below:
· Make sure that air can freely flow across the coils. Don't close the refrigerator into a confined space unless it's a model that is specially designed to be "built in." Leave at least a 1" space on each side of the unit to allow for adequate air flow to carry heat away.
· Install refrigerators and freezers away from heat sources, such as oven and dishwashers, and out of direct sunlight.
· It often makes sense to install freezers in a cooler basement or attached garage, though manufacturers recommend against installation in locations where temperatures can drop below freezing.
Maintenance
· Keep the condenser coils clean. Dust and dirt accumulation on the heat exchanger coils on the back or bottom of a refrigerator will reduce its efficiency. They should be vacuumed off at least once a year- more often if your home is particularly dusty. Follow the manufacturers instructions for cleaning, and as a safety precaution, unplug the unit while moving and cleaning it.
· Check door seals and replace if leaky or worn. To test the seals, close a dollar bill in the door. If the dollar bill pulls out with no resistance, the seals probably should be replaced.
· Check the temperature settings and adjust as necessary. The refrigerator compartment should be between 36½F and 38½F, and the freezer compartment between 0½F and 5½F. Lower temperature settings are unnecessary and waste energy.
· Defrost as necessary. Ice buildup on the coils decreases heat transfer and reduces overall efficiency of refrigerators and freezers. Manual defrost and partial automatic defrost refrigerators and freezers should be defrosted whenever ice builds up more than 1/4" on the coils.
Operation
· Avoid putting containers of hot food in a refrigerator or freezer. Let them cool first.
· Keep your freezer fairly full- it will perform better than if it is nearly empty. You can fill plastic containers with water and freeze them to fill up extra capacity.
· Rethink that old spare refrigerator running in the basement. It may be costing you as much as $200 per year to keep a couple of six-packs of beer cold. If you decide to stop using it, unplug it and remove the door for safety.
Dishwashers
Water heating accounts for about 80 percent of the energy use of dishwashers; most of the rest is for the electric drying cycle. As a result, the most important strategies to reduce energy use involve cutting hot water use and limiting usage of the electric drying cycle.
Buying a new dishwasher
The EnergyGuide labels on new dishwashers list annual operating cost, but it is important to note that the EnergyGuide ratings are based on very specific operating cycles, and that they do not factor in certain energy-saving features.
· Look for an energy-saving wash cycle option. Many dishwashers offer a "light wash" cycle that uses less water and operates for a shorter period of time. This cycle will be perfectly adequate for lightly soiled dishes, and it will save energy.
· Buy a dishwasher that has a built-in booster heater. To perform optimally, dishwashers need 140-145½F water. Many dishwashers have booster heaters that can heat water from 110½F or 120½F up to the required temperature. The advantage, from an energy standpoint, is that with a booster heater, you can turn down the temperature setting on your water heater, thereby avoiding unnecessary standby losses.
Installation
· Position the dishwasher as close as possible to the water heater to minimize the piping run and resultant heat loss.
Operation
· If your dishwasher has a lower-water-use light-wash cycle, use it whenever possible.
· Use the no-heat air-dry feature on your dishwasher. If you have an older model without this feature, you can turn off the dishwasher and open the door after the final rinse cycle to let the dishes air dry. Be aware that drying will take longer, however, and some spotting is possible.
· If your dishwasher has a booster heater, turn the thermostat on your water heater down to 120-130½F (check the dishwasher manufacturer's recommendations for minimum water heater setting).
· Avoid the temptation to pre-rinse dishes before putting them in the dishwasher. Most quality dishwashers today do an excellent job without pre-rinsing. Simply scrape off solids and pour out liquids before loading dishes. If you must rinse dishes first, use cold water.
· Wash full loads. A dishwasher will use the same amount of water (and energy) whether it is washing a full load or a nearly empty load. If possible, gradually fill up the dishwasher during the day and operate it just once, at night. However, don't overfill the washer to save "even more" energy. You need to leave plenty of room for water to circulate between dishes for proper cleaning.
· If you have a dishwasher but usually wash dishes by hand, you might not be saving any energy. If you tend to leave the water running while washing dishes, you would probably reduce your water and energy use by using the dishwasher instead.
Clothes washers and dryers
The average energy cost for washing and drying one load of clothes ranges from 17¢ to $1.10 at current Virginia energy prices. As with dishwashers, most of the energy use of washing machines is for water heating, so it's best to use less water and cooler settings. With dryers, the primary differences in energy use among different machines relates to how they sense when the clothes are dry. Gas dryers also generally cost a lot less to operate than electric models. You can usually save the most energy (and money) by changing the way you do the laundry. In fact, a load of laundry that is washed and rinsed in cold water, and hung on a line to dry, uses only about 3¢ worth of energy. Tips on buying and operating washers and dryers for maximum energy savings are presented below.
Buying a new washing machine
· Compare EnergyGuide labels of the different washing machines you are considering.
· Look for a model that lets you adjust the wash and rinse temperature settings individually. With warm and cold cycles, your energy and dollar savings can be dramatic, as shown in Table 1.
TABLE - 1
COST OF A LOAD OF LAUNDRY
Electric water heater Gas water heater
Wash/rinse
settings kWh
used Avg.cost
per load
(cents)1 Wash/rinse
settings Therms
used Avg. cost
per load
(cents)2
Water heater thermostat set at 140ºF
Hot/Hot 8.3 66 Hot/Hot .329 20
Hot/Warm 6.3 50 Hot/Warm .247 15
Hot/Cold 4.3 34 Hot/Cold .164 10
Warm/Warm 4.3 34 Warm/Warm .164 10
Warm/Cold 2.3 18 Warm/Cold .082 5
Cold/Cold 0.4 3 Cold/Cold --- 3
Water heater thermostat set at 120ºF
Hot/Hot 6.5 52 Hot/Hot .248 15
Hot/Warm 4.9 39 Hot/Warm .186 10
Hot/Cold 4.3 27 Hot/Cold .124 7
Warm/Warm 3.4 27 Warm/Warm .124 7
Warm/Cold 1.9 15 Warm/Cold .062 4
Cold/Cold 0.4 3 Cold/Cold --- 3
1. Assumes 8 cents per kWh.
2. Assumes 60 cents per therm.
*Source: Consumer Guide to Home Energy Savings, ACEEE, 1996.
You will need to determine for yourself whether or not the lower-temperature wash settings clean your clothes as well as hotter settings. Cold-water rinses are just as effective as warm-water rinses, so they should always be selected.
· Choose a model that offers different water level settings, allowing you to use less water (and energy) for smaller loads. A typical top-loading machine uses about 20 gallons per load for the smallest setting, and up to 40 gallons per load for the largest.
· Consider a front-loading (horizontal-axis) model instead of a standard top-loader. Front-loaders use about half as much water and energy as top-loaders, and some say the washing performance is actually better. Along with saving money for water heating, a front-loading machine can cut your water and sewage bills (if you are on a municipal system), extend the life of a rural septic system, and save a lot of money on detergent.
· Water extraction. The more water your washing machine extracts during its spin cycle, the less your dryer will have to work. Some (but not all) manufacturers list the water extraction specifications in their literature.
Buying a new dryer
· Choose a dryer that shuts off automatically when the clothes become dry instead of one that can only operate on a timed cycle. If the only option is a timed cycle, you might be wasting a lot of energy by just heating clothes that are already dry- and damaging the clothes as well. The best controls have actual moisture sensors, while others sense only the temperature of the exhaust air.
· Gas dryers are usually much less expensive to operate than electric models- at least if you are able to use natural gas rather than propane. All gas dryers sold today are required to have electronic ignition instead of pilot lights. If you are considering buying a used model, be aware that the pilot light can waste a lot of energy.
Installation of washers and dryers
· Install the washing machine as close to the water heater as possible, and insulate the hot water pipes.
· Install a quality dryer vent hood that blocks return airflow. Standard metal vent hoods can result in considerable heat loss and cold air drafts. Dryers should always be vented to the outside. Use smooth metal ducting so as not to impede airflow.
· Never vent a dryer inside - not even an electric model. The exhaust contains chemical contaminants and lots of moisture which can affect indoor air quality.
· Install washer and dryer in a heated space. Dryers in particular work more efficiently in heated spaces than unheated spaces (such as garages).
Operation and maintenance
· Turn down your water heater. 120½F water will be adequate for most washing needs that require "hot" water.
· Fill the washing machine to capacity, but don't overload. Most people tend to under-load washing machines, necessitating extra loads. When you don't have enough laundry to fill up the washing machine, use a lower water volume setting.
· Use the energy-saving wash settings (lower temperature, water volume matched to load size). Cold-water washing offers the greatest energy savings, and with detergents specially formulated for cold water, washing performance is usually satisfactory. Always use cold-water rinse settings.
· Try to separate your clothes into like fabrics that will dry at a similar rate. Synthetics generally dry much faster than cottons.
· Never add wet clothes to a load of laundry that is already partially dry.
· Be careful not to overdry clothes. Experiment with the settings on the automatic drying control, as many tend to overdry. You may find that the "less dry" is plenty dry enough. By taking the clothes out when they are still slightly damp, you not only save energy, but also may reduce wear and tear on the fabric and reduce the need for ironing. If possible, dry two or more loads in a row to benefit from the residual heat in the dryer.
· Clean the dryer lint trap regularly for improved drying efficiency and safety (follow manufacturer's instructions). Accumulated lint prevents moisture from escaping and can be a fire hazard.
· Periodically check the outside dryer exhaust hood to make sure that it isn't blocked and that the flapper or seal is in proper working order.
· In good weather, hang your laundry outside and use free solar energy to dry your clothes.
Cooking appliances
Selecting cooking equipment has gotten a lot more complex in recent years. Along with the old stand-by gas or electric kitchen range with oven and top burners, we now have microwave ovens, high-tech halogen and induction cook-tops, down-vented ranges with pop-out grills, convection ovens, slow-cook crockpots (insulated ceramic pot with electric heating element), single-loaf bread ovens, and sophisticated counter-top toaster ovens.
Just as importantly, our living and cooking habits have changed. Two career families need to consider speed and efficiency in cooking, plus the possibility of programming appliances to operate while family members are at work. There are no EnergyGuide labels for cooking equipment, because within a given model category and style there is very little difference in energy use between brands.
Cooktops
Cooktops can be part of a standard kitchen range, or a separate unit built into a counter. Different types of gas and electric cooktops are described below, with ovens discussed separately afterwards.
Gas cooktops
Many cooks prefer gas burners because they offer instant heat and greater temperature control. All new gas cooktops are required to have electronic ignition instead of wasteful pilot lights. Some new models have sealed burners which make them easier to keep clean, but do not affect their energy use. You should always operate an exhaust fan when using a gas range to remove products of combustion as well as steam, grease, and cooking odors.
Electric cooktops
Exposed electric coils are the most common type of electric burner, and generally the least expensive. Several other types of electric cooktops are described below. Of these, only the induction elements offer significant energy savings over standard electric coils, and these elements are so expensive that the cost cannot be justified for energy savings alone.
Solid disk elements. Solid disk elements look better and are easier to clean than electric coils, but they take longer to heat up and cool down so they tend to use more energy. The disks transfer heat to pans primarily through direct contact, so it is important to have good flat-bottomed pans for maximum contact between the disk surface and the pan.
Radiant elements under ceramic glass. Ceramic glass cooktops heat up more quickly than solid disk elements, though not as quickly as electric coils. They are more efficient than solid disks, and some are even more efficient than coil elements. Ceramic glass cooktops are quite expensive, however. As with solid disks, flat bottomed pans for good contact are important.
Halogen elements under ceramic glass. Halogen cooktops use halogen lamps under a ceramic glass surface to heat the cooking vessel. The lamps heat up very quickly, offering improved cooking control and providing slightly improved efficiency compared to standard radiant elements under ceramic glass cooktops. As with standard radiant elements, halogen elements require good contact between the pans and the surface.
Induction elements. Induction elements transfer electromagnetic energy directly to the pan containing the food. Since they don't waste any heat on the cooking surface, they are very efficient, using less than half the energy of standard electric coil ranges. Induction elements require the use of ferrous metal pans (iron or stainless steel); aluminum cookware will not work. Induction cooktops are also very expensive, making them hard to justify for energy savings alone.
Ovens
Standard gas and electric ovens are available either combined with cooktops (typical kitchen range), or as independent units. Newer convection ovens and microwave ovens can provide considerable energy savings. Smaller specialized cooking appliances that can be used in place of full-size ovens and cooktops are also potential energy savers. These appliances include slow-cook crockpots, individual-loaf bread cookers, and counter-top toaster ovens.
Standard ovens
Among standard gas and electric ovens, those with a self-cleaning feature tend to be more efficient, because they have more insulation in the walls. Using this feature too often however (more than once a month) will cancel out any energy savings from the extra insulation, because so much energy is required for the self-cleaning. Ovens with no window in the door will be more energy-efficient than those with one. The slight advantage may be lost, however, if the lack of a window makes the cook repeatedly open the door to check the food.
Convection ovens
Convection ovens offer considerable energy savings because a fan circulates hot air throughout the oven compartment, allowing cooking temperatures and cooking time to be reduced. (See Table 2).
TABLE - 2
ENERGY COSTS OF VARIOUS METHODS OF COOKING
Appliance Temp. Time Energy Cost(1)
Electric oven 350ºF 1 hr. 2.0 kWh 16¢
Convection oven (elec.) 325º 45 min. 1.39 kWh 11¢
Gas oven 350º 1 hr. .112 therm 7¢
Frying pan 420º 1 hr. .9 kWh 7¢
Toaster oven 425º 50 min. .95 kWh 8¢
Crockpot 200º 7 hrs. .7 kWh 6¢
Microwave oven "High" 15 min. .36 kWh 3¢
1. Assumes 8¢/kWh for electricity and 60¢/therm for gas.
*Source: Consumer Guide to Home Energy Savings, ACEEE, 1996.
Microwave ovens
Introduction of the microwave oven was the most significant advance in cooking in the last fifty years. Cooking times can be reduced dramatically with many foods, and total energy consumption for cooking can be reduced by about two-thirds. You can save further by reducing the number of dishes to wash (you can serve food in the dishes it is cooked in), and by introducing less heat into the kitchen (you won't need to operate an air conditioner as frequently).
Ventilation
A range hood or other ventilation fan is very important for exhausting fumes and smells out of the house. When cooking with gas the fan should be running continuously. The exhaust fan must blow the air out of the house, not just recirculate it through a filter. A variable speed fan is the best option, since it allows control over how much air is exhausted.
There is a danger, however, with exhaust fans that are too powerful, particularly the popular downdrafting types, some of which are as large as 1,000 cfm (cubic feet per minute). When operating, these fans depressurize the house, drawing cold outside air in through cracks and gaps in your walls. This depressurization can also cause hazardous backdrafting of combustion appliances. If you do install a large ventilation fan, consider putting in a makeup air supply to balance the exhaust air.
Tips for energy-efficient cooking
· Instead of using your full-size oven for cooking small dishes, use a microwave oven, toaster oven, or slow-cook crockpot. A number of different ways of cooking a casserole are compared in Table 2.
· For stove-top cooking of rice, beans, and other foods that require a long cooking time, consider a pressure cooker, which will reduce cooking time considerably.
· For stove-top cooking, use the smallest pan necessary to do the job. With electric cooktops, try to match the pan size to the element size.
· Copper or aluminum-bottomed pans heat up more quickly than steel or cast-iron pans and can thus save energy.
· Clean the burner pans (the metal pans under burners used to catch grease) and keep them shiny so that they will reflect more heat up to your cooking vessel.
· With electric burners, including solid-disk and ceramic cooktops, make sure your pots and pans have flat bottoms to provide good heat contact between burner and pan.
· Cook with lids on your pans. Without a lid, cooking spaghetti can use three times as much energy.
· With gas burners, the flame should be blue. If you have a yellowish flame, the burner might not be operating efficiently. Have your gas company inspect it.
· To reduce cooking time, defrost frozen foods in the refrigerator before cooking. When time constraints require quicker defrosting, use the microwave.
· Minimize oven preheat time. With most dishes, preheating the oven is not necessary.
· Avoid the temptation to open the oven door.
· To allow air circulation within an oven, don't lay foil across the grills. Try to stagger pans on the shelves to allow air circulation.
· When possible, cook several dishes at the same time in the oven. Cook double portions and freeze half for another meal. It takes a lot less energy to reheat food than to cook it.
· For oven cooking, use glass or ceramic pans instead of metal. You can usually turn the oven down 25½ and not increase the cooking time.
· Avoid overcooking. Use meat thermometers and timers.
· If you have a self-cleaning oven, try to use it soon after cooking a meal so that the oven will already be warm. Limit use as much as practical.
· Keep the inside surface of microwave ovens clean to improve efficiency, and cook foods right in microwave-safe serving dishes (follow manufacturer's instructions on what type of cookware can be used in a microwave oven).
Miscellaneous appliances
There are lots of other energy users around the typical home, some of which can be very significant. A few of them are described below. Others are listed in Table 3.
Table 3 - Energy Consumption of Miscellaneous Appliances in the Home
Household Product Typical Wattage Typical Usage Cost Per year
@ $.76/kWh
Bathroom fan 60 1hr/day $1.66
Black & white television 556 0.6 hrs/day 9.15
Bottled water dispenser
- (hot & cold) 65 24 hrs/day- 203 kWh/hr 15.43
Ceiling fan 23 hrs/day-5mos/yr 2.22
Clock 860 24 hrs/day 1.33
Coffee maker 200 2 times/day 10.16
Color television 200 6 hrs/day 33.29
Computer 250 2 hrs/day 11.10
Dehumidifier 200 7 hrs/day-5 mos/yr 19.95
Electric blanket 200 4 hrs/day-5 mos/yr 9.12
Electric mower 900 12 hrs/yr 0.82
Furnace fan 300 1600 hrs/yr 35.36
Garbage disposal 450 22 hrs/yr 0.75
Humidifier 170 360 hrs/yr 4.66
Instant hot water 7000 2 hrs/wk 55.33
Iron 1100 4 hrs/mo 4.01
Spa/hot tub (electric) 2000 3 hrs/day 166.44
Sump/sewage pump 500 80 hrs/yr 3.04
Toaster 1100 2 hrs/mo 2.03
Toaster oven 1500 4 hrs/mo 5.47
VCR 20 4 hrs/day 2.22
Waterbed heater 350 7 hrs/day 67.96
Well pump 750 1.5 hrs/day 31.21
Whole-house fan 375 6 hrs/day-5 mos/yr 25.65
Window fan 200 3 hrs/day-5 mos/yr 6.84
Humidifiers
Can make you feel more comfortable in the winter months, when your household air tends to dry out, but some models use a considerable amount of energy to operate. If your home is too dry, consider reducing the natural air leakage (see Chapter 2). By reducing the amount of air exchange between the inside and outside during the winter, you will maintain higher humidity levels indoors. House plants also help to add moisture to the indoor air.
Dehumidifiers
Used most commonly to keep basements dry, dehumidifiers can use significant amounts of electricity. One way to reduce dehumidifier energy consumption is to find and eliminate some of the moisture sources. Some possible sources are stored firewood in the basement, water leaking into the basement, and inadequate kitchen and bathroom ventilation. Be sure to keep windows closed when running a dehumidifier.
Home Office Equipment
With more people working out of their homes, energy use for computers, laser printers, copiers, and other office equipment is on the increase. When selecting equipment, consider the energy use. Laser printers, for example, use far more electricity than ink-jet printers and dot-matrix printers. Similarly, laptop computers use just a fraction of the electricity of desktop models. With copiers, look for models that have a low-energy-use standby mode.
On the subject of home offices, it is worth noting that the amount of energy you save by working at home and not commuting regularly to work will almost always more than make up for the increased energy use at home
· plus you would probably be using just as much energy at an office anyway.
Waterbed heaters
Surprisingly, a waterbed can be the single largest electricity consumer in the home, exceeding even the electricity use of a refrigerator. To reduce energy use by your waterbed, be sure to cover it with a comforter during the day, a simple measure that can cut energy use by 30 percent. Insulating the sides of the bed can save another 10 percent. You might also want to put the heater on a timer so that it isn't keeping the waterbed warm all the time. Some people don't use heaters at all, and instead insulate themselves from the waterbed with blankets or foam padding.
Well pumps
In rural areas that are not on municipal water systems, a lot of energy can be required for pumping water out of deep wells. Any measures taken to reduce water use in the home (low-flush toilets, low-flow showerheads, faucet aerators, water-saving cycles on the dishwasher and clothes washer, etc.) will reduce energy used for water pumping. If the pump seems to be coming on more than it should, there may be a leak somewhere in the system, or the pressure switch may be malfunctioning. Have the system inspected.
Spas and hot tubs
While not found in most homes, spas and hot tubs can be huge energy users. If you have one, be sure to buy and use an insulated cover. When installing a hot tub, insulate well around the sides and bottom.
Color television sets
Some color television sets have an instant-on feature to avoid the long warm-up period. While the convenience feature is nice, it wastes a lot of energy because the TV is never fully off. If you have an older television with this feature, consider installing a switch on the power cord to turn it all the way off when not in use, or unplug it.

Keeping an eye on your energy/water use: a simple chart

Kenton Shepard (Peak to Prairie Inspection Service) — Sun, 15 Apr 2007 10:52:02 -0500

In arid parts of the county water is becoming more important as aquifers containing fossil water- ancient water which is not replenished by runoff- is used up. In these parts of the country, which includes most of the West, it's important to conserve water.

Ever wondered how much hot water your family uses? Check our hot water usage chart to find out:

Use	Gallons per use
Shower	7-10
Bath (standard tub)	20
Bath (whirlpool tub)	35-50
Clothes washer (hot water wash, warm rinse)	32
Clothes washer (warm wash, cold rinse)	7
Automatic dishwasher	8-10
Food preparation and cleanup	5
Personal (hand-washing, etc.)	2

New Thinking about Attic ventilation

Kenton Shepard (Peak to Prairie Inspection Service) — Thu, 12 Apr 2007 16:51:05 -0500

By Kenton Shepard

Most of us agree that keeping the attic cool is a good thing. Keeping the attic cool helps keep the roof-covering material cool which extends its lifespan. During the summer, ventilating the attic helps lower the cost of keeping the home cool. During the winter it helps prevent ice dams from forming and damaging roofing material.

In the past, popular thought held that the best way to vent an attic was to provide inlet vents along the lower edges of the roof, usually in the soffits, and an outlet vent, usually a continuous ridge vent, at the roof peak. The theory was that since hot air rises, this would provide for optimum flow as the roof and attic area became hotter during the day. Hot air rising is called "thermal boyancy".

The newest thinking on attic space ventilation is that air pressure caused by wind moving past the home has a much greater effect in moving air through the attic space than thermal boyancy. Here's why...

As wind blows past the home, a vacuum (an area of low air pressure) is created on the downwind side of the home. As we all know, nature abhors a vacuum and tries to fill it. Anything that can move into that area of low pressure will move into it, including air from the attic. So basically the theory is that air will be pulled out of the soffit vents before it has a chance to rise and exit through the countinuous ridge vent.

On a day when there is no wind, or when the wind blows parallel to the ridge line this this system will obviously not work as I have described it.

Using the same principles (air moves into areas of low pressure) a continuouse soffit vent which has baffles which route the wind up and over the vent cover will be more effective in vetilating the attic than using a vent with no baffles. As the wind move up and over the vent cover, an area of low pressure is created just above the vent cover which pulls air out of the attic space.

This all works on the same principle which moves a sailboat through the water. It's not the wind pushing on the sails, but the area of low pressure in front of the sail, created when the wind blows past the sail, into which the boat is pulled by the sail.

One last note on keeping roof-covering materials cool. Ventilation has maybe a 5% effect on roof material temperature. The greates effect by far is the color of the roofing material. Black roofs absorb around 95% of the light stiking them and turn the light into heat. White roofs will reflect around 95% of the light striking them and if the light is reflected, it's not turned into heat.

The Benefits of a High-performance Home

Kenton Shepard (Peak to Prairie Inspection Service) — Thu, 12 Apr 2007 15:57:24 -0500

High Performance Homes

E-Star's statewide home energy rating program facilitates the design and construction of energy-efficient homes and High Performance Homes.

Definition

A High Performance Home relies on systems-engineered design, quality-controlled construction, and performance testing to ensure that it is healthy, comfortable, affordable, energy-efficient, durable, and environmentally responsible.

To qualify as a High Performance Home, the dwelling must consume 40% less energy than a home built to the 1995 Model Energy Code. Such an energy-efficient home will receive a score of 86 points or more on the 100-point E-Star Home Energy Rating scale. High Performance Homes can receive the ENERGY STAR^® label, which is issued by the U.S. Environmental Protection Agency. Homes that score between 80 and 85 points on the E-Star scale are energy-efficient but cannot display the ENERGY STAR^® label.

Benefits to Homebuyer

A High Performance Home offers many benefits to owner and occupants:

Saves money. The high scores on the E-Star Home Energy Rating mean the home will generate lower utility bills.
Increased comfort. The added features of High Performance Homes-quality windows, high-efficiency heating systems, and increased insulation in walls and attics and around pipes and ducts-improve the comfort level in the dwelling.
Robust structure. High Performance Homes incorporate durable construction practices that increase the life and robustness of a home.
Healthy air. Other features of High Performance Homes, such as careful use of vapor barriers and conscious ventilation, improve moisture control and indoor air quality.

E-Star's Contributions

Increasing the number of High Performance Homes contributes to the overall E-Star goal of promoting energy conservation in buildings.
Measurement scale. The E-Star Home Energy Rating system makes it possible to measure the performance of these homes in a consistent way with a comparable format.
Trained Raters. E-Star trains and certifies E-Star Raters, independent contractors who perform the work for profit. E-Star controls the quality of Raters' work to ensure consistent and comparable ratings.
Technical resource. Raters and builders can rely on the E-Star program's technical staff to facilitate design and construction of High Performance Homes.
Homeowner education. E-Star works with builders of High Performance Homes to tell homebuyers about the link between good building science and higher comfort, increased durability, lower long-term ownership costs, and healthy indoor air quality.

Related Information

Home Energy Ratings

ENERGY STAR^® Web Site

Building America

Basement Insulation and Mold
Steve Andrews, Homebuilder Magazine, August 2002. (PDF)

A Growing Market for High Performance Homes

Aluminum Wiring can be Made Safe

Kenton Shepard (Peak to Prairie Inspection Service) — Thu, 12 Apr 2007 15:41:43 -0500

Aluminum wiring that is installed correctly and has been correctly maintained is acceptable, however wiring is often neglected and neglected aluminum wiring is a potential fire hazard.

Aluminum Wiring Hazards

Between 1965 and 1973 aluminum wiring was sometimes substituted for copper wiring in residential electrical systems.

Connections in outlets, switches and light fixtures with aluminum wiring become increasingly dangerous as time passes. Poor connections cause wiring to overheat, creating a potential fire hazard.

In addition to creating a potential fire hazard, the presence of aluminum wiring may have an effect on your insurance policy. You should ask your insurance agent whether the presence of aluminum wiring is a problem that requires changes to your policy language in order to ensure that your house is covered.

Options for Correction

The wiring should be evaluated by a qualified electrician. This means an electrician experienced in evaluating and correcting aluminum wiring problems. Not all electrical contractors qualify.

At the minimum all connections should be checked and an anti-oxident paste applied. Other options are splicing copper wire at the connections (called "pigtailing", not a great option) and copalum crimps which, although they are the safest option, are expensive (around $50 per outlet and switch).

Here are the reasons aluminum wiring connections deteriorate:

Thermal expansion and contraction:
Even more than copper, aluminum expands and contracts with changes in temperature. Over time, this will cause connections to loosen. When wires are poorly connected they overheat, which creates a potential fire hazard.

Vibration:
Electrical current vibrates as it passes through wiring. This vibration is more extreme in aluminum than it is in copper and as time passes, it can cause connections to loosen. Again, when wires are poorly connected they overheat, which creates a potential fire hazard.

Oxidation:
Exposure to oxygen in the air causes deterioration to the outer surface of wire. This process is called oxidation. Aluminum wire is more easily oxidized than copper wire and as time passes, this process can cause problems with connections. Again, when wires are poorly connected they overheat, which creates a potential fire hazard.

Galvanic corrosion:
When two different kinds of metal are connected to each other a very low-voltage electrical current is created which causes corrosion. Corrosion causes poor connections.

More information is available at this comprehensive website. http://www.inspect-ny.com/aluminum/aluminum.htm

Some homes with basements, crawlspaces or attics which provide good access may be re-wired at a surprisingly reasonable cost. Other homes may be very expensive to re-wire.

Heating System Efficiency: Understanding Efficiency Ratings, Retrofitting and Replacement

Kenton Shepard (Peak to Prairie Inspection Service) — Thu, 12 Apr 2007 11:44:56 -0500

HEATING EQUIPMENT

Programmable Thermostats

Using a programmable thermostat, heating and air-conditioning schedules can be adjusted according to a pre-set schedule. As a result, the equipment doesn't operate as much when it's not needed. Programmable thermostats can store and repeat multiple daily settings (six or more temperature settings a day) that you can manually override without affecting the rest of the daily or weekly program.

Furnaces and Boilers

Most U.S. homes are heated with either furnaces or boilers. Furnaces heat air and distribute the heated air through the house using ducts; boilers heat water, providing either hot water or steam for heating. Steam is distributed via pipes to steam radiators, and hot water can be distributed via baseboard radiators or radiant floor systems, or can heat air via a coil. Steam boilers operate at a higher temperature than hot water boilers, and are inherently less efficient, but high-efficiency versions of all types of furnaces and boilers are currently available.

Understanding the Efficiency Rating of Furnaces and Boilers

A central furnace or boiler's efficiency is measured by annual fuel utilization efficiency (AFUE). The Federal Trade Commission requires new furnaces or boilers to display their AFUE so consumers can compare heating efficiencies of various models. AFUE is a measure of how efficient the appliance is in the energy in its fuel over the course of a typical year.

Specifically, AFUE is the ratio of heat output of the furnace or boiler compared to the total energy consumed by a furnace or boiler. An AFUE of 90% means that 90% of the energy in the fuel becomes heat for the home and the other 10% escapes up the chimney and elsewhere. AFUE doesn't include the heat losses of the duct system or piping, which can be as much as 35% of the energy for output of the furnace when ducts are located in the attic.

An all-electric furnace or boiler has no flue loss through a chimney. The AFUE rating for an all-electric furnace or boiler is between 95% and 100%. The lower values are for units installed outdoors because they have greater jacket heat loss. However, despite their high efficiency, the higher cost of electricity in most parts of the country makes all-electric furnaces or boilers an uneconomic choice. If you are interested in electric heating, consider installing a heat pump system.

The minimum allowed AFUE rating for a non-condensing fossil-fueled, warm-air furnace is 78%; the minimum rating for a fossil-fueled boiler is 80%; and the minimum rating for a gas-fueled steam boiler is 75%. A condensing furnace or boiler condenses the water vapor produced in the combustion process and uses the heat from this condensation. The AFUE rating for a condensing unit can be much higher (by more than 10 percentage points) than a non-condensing furnace. Although condensing units cost more than non-condensing units, the condensing unit can save you money in fuel costs over the 15- to 20-year life of the unit, and is a particularly wise investment in cold climates.

You can identify and compare a system's efficiency by not only its AFUE but also by its equipment features, listed below.

Old, low-efficiency heating systems:

Natural draft that creates a flow of combustion gases
Continuous pilot light
Heavy heat exchanger
68%-72% AFUE

Mid-efficiency heating systems:

Exhaust fan controls the flow of combustion air and combustion gases more precisely
Electronic ignition (no pilot light)
Compact size and lighter weight to reduce cycling losses
Small-diameter flue pipe
80%-83% AFUE

High-efficiency heating systems:

Condensing flue gases in a second heat exchanger for extra efficiency
Sealed combustion
90%-97% AFUE

Retrofitting Your Furnace or Boiler

Furnaces and boilers can be retrofitted to increase their efficiency. These upgrades improve the safety and efficiency of otherwise sound, older systems. The costs of retrofits should be carefully weighed against the cost of a new boiler or furnace, especially if replacement is likely within a few years or if you wish to switch to a different system for other reasons, such as adding air conditioning (see the section on selecting and replacing heating and cooling systems). If you choose to replace your gas heating system, you'll have the opportunity to install equipment that incorporates the most energy-efficient heating technologies available.

Since retrofits are fuel-specific, see the following sections for retrofit information:

Gas-Fired Furnaces and Boilers (includes units fired with natural gas and propane)
Oil-Fired Furnaces and Boilers

Other retrofitting options that can improve a system's energy efficiency include installing programmable thermostats, upgrading ductwork in forced-air systems, and adding zone control for hot-water systems, an option discussed in the Heat Distribution Systems section.

Replacing Your Furnace or Boiler

Although older furnace and boiler systems had efficiencies in the range of 56%-70%, modern conventional heating systems can achieve efficiencies as high as 97%, converting nearly all the fuel to useful heat for your home. Energy efficiency upgrades and a new high-efficiency heating system can often cut your fuel bills and your furnace's pollution output in half. Upgrading your furnace or boiler from 56% to 90% efficiency in an average cold-climate house will save 1.5 tons of carbon dioxide emissions each year if you heat with gas, or 2.5 tons if you heat with oil.

If your furnace or boiler is old, worn out, inefficient, or significantly oversized, the simplest solution is to replace it with a modern high-efficiency model. Old coal burners that were switched over to oil or gas are prime candidates for replacement, as well as gas furnaces with pilot lights rather than electronic ignitions. Newer systems may be more efficient but are still likely to be oversized, and can often be modified to lower their operating capacity.

Before buying a new furnace or boiler or modifying your existing unit, first make every effort to improve the energy efficiency of your home, then have a heating contractor size your furnace. Energy-efficiency improvements will save money on a new furnace, because you will need a smaller furnace. A properly sized furnace will also operate most efficiently. You'll also want to look for a dependable unit and compare the warranties of each furnace or boiler under consideration.

When shopping for high-efficiency furnaces and boilers, look for the ENERGY STAR label. If you live in a cold climate, it usually makes sense to invest in the highest-efficiency system. In milder climates with lower annual heating costs, the extra investment required to go from 80% to 90%-95% efficiency may be hard to justify.

You can estimate the annual savings from heating system replacements by using Table 1. The table assumes that both furnaces have the same heat output. However, most older systems are oversized, and will be particularly oversized if you significantly improve the energy efficiency of your home. Because of this additional benefit, your actual savings in upgrading to a new system could be much higher than indicated in the table.

Specify a sealed combustion furnace or boiler, which will bring outside air directly into the burner and exhaust flue gases (combustion products) directly to the outside, without the need for a draft hood or damper. Furnaces and boilers that are not sealed-combustion units draw heated air into the unit for combustion and then send that air up the chimney, wasting the energy that was used to heat the air. Sealed-combustion units avoid that problem and also pose no risk of introducing dangerous combustion gases into your house. In furnaces that are not sealed-combustion units, backdrafting of combustion gases can be a big problem.

High-efficiency sealed-combustion units generally produce an acidic exhaust gas that is not suitable for old, unlined chimneys, so the exhaust gas should either be vented through a new duct or the chimney should be lined to accommodate the acidic gas (see the section on maintaining proper ventilation, below).

Table 1. Annual Estimated Savings for Every $100 of Fuel Costs by Increasing Your Heating Equipment Efficiency*
Existing System AFUE	New/Upgraded System AFUE
Existing System AFUE	55%	60%	65%	70%	75%	80%	85%	90%	95%
50%	$9.09	$16.76	$23.07	$28.57	$33.33	$37.50	$41.24	$44.24	$47.36
55%	----	$8.33	$15.38	$21.42	$26.66	$31.20	$35.29	$38.88	$42.10
60%	----	----	$7.69	$14.28	$20.00	$25.00	$29.41	$33.33	$37.80
65%	----	----	----	$7.14	$13.33	$18.75	$23.52	$27.77	$31.57
70%	----	----	----	----	$6.66	$12.50	$17.64	$22.22	$26.32
75%	----	----	----	----	----	$6.50	$11.76	$16.66	$21.10
80%	----	----	----	----	----	----	$5.88	$11.11	$15.80
85%	----	----	----	----	----	----	----	$5.55	$10.50
90%	----	----	----	----	----	----	----	----	$5.30

*Assuming the same heat output

Maintaining Furnaces and Boilers

The following maintenance should be provided by a heating system professional.

All systems:

Check the condition of your vent connection pipe and chimney. Parts of the venting system may have deteriorated over time. Chimney problems can be expensive to repair, and may help justify installing new heating equipment that won't use the existing chimney.
Check the physical integrity of the heat exchanger. Leaky boiler heat exchangers leak water and are easy to spot. Furnace heat exchangers mix combustion gases with house air when they leak-an important safety reason to have them inspected.
Adjust the controls on the boiler or furnace to provide optimum water and air temperature settings for both efficiency and comfort.
If you're considering replacing or retrofitting your existing heating system, have the technician perform a combustion-efficiency test.

Forced-air Systems:

Check the combustion chamber for cracks
Test for carbon monoxide (CO) and remedy if found
Adjust blower control and supply-air temperature
Clean and oil the blower
Remove dirt, soot, or corrosion from the furnace or boiler
Check fuel input and flame characteristics, and adjust if necessary
Seal connections between the furnace and main ducts.

Hot-water Systems:

Test pressure-relief valve
Test high-limit control
Inspect pressure tank, which should be filled with air, to verify that it's not filled with water
Clean the heat exchanger.

Steam Systems:

Drain some water from the boiler to remove sediments. This improves the heat exchange efficiency
Test low-water cutoff safety control and high-limit safety control
Drain the float chamber to remove sediments. This prevents the low-water cutoff control from sediment clogs
Analyze boiler water and add chemicals as needed to control deposits and corrosion
Clean the heat exchanger
See also the section on steam radiators.

Maintaining Proper Ventilation for Combustion Systems

Anytime you maintain, retrofit, or replace a gas heating system you also need to be concerned with air quality. Combustion air is needed by all oil and gas heating systems to support the combustion process. This air is provided in some homes by unintentional air leaks, or by air ducts that connect to the outdoors. The combustion process creates several byproducts that are potentially hazardous to human health and can cause deterioration in your home. You can protect yourself from these hazards, as well as maintain energy efficiency, by ensuring that your chimney system functions properly and that your gas heating system is properly ventilated. In some cases, installing a sealed-combustion furnace or boiler can also help.

Chimneys

Properly functioning chimney systems will carry combustion byproducts out of the home. Therefore, chimney problems put you at risk of having these byproducts, such as carbon monoxide, spill into your home.

Most older gas furnaces and boilers have naturally drafting chimneys. The combustion gases exit the home through the chimney using only their buoyancy combined with the chimney's height. Naturally drafting chimneys often have problems exhausting the combustion gases because of chimney blockage, wind or pressures inside the home that overcome the buoyancy of the gases.

Atmospheric, open-combustion furnaces and boilers, as well as fan-assisted furnaces and boilers, should be vented into masonry chimneys, metal double-wall chimneys, or another type of manufactured chimney. Masonry chimneys should have a fireclay, masonry liner or a retrofitted metal flue liner.

Many older chimneys have deteriorated liners or no liners at all and must be relined during furnace or boiler replacement. A chimney should be relined when any of the following changes are made to the combustion heating system:

When you replace an older furnace or boiler with a newer one that has an AFUE of 80% or more. These mid-efficiency appliances have a greater risk of depositing acidic condensation droplets in chimneys, and the chimneys must be prepared to handle this corrosive threat. The new chimney liner should be sized to accommodate both the new heating appliance and the combustion water heater by the installer.
When you replace an older furnace or boiler with a new 90+ AFUE appliance or a heat pump. In this case, the heating appliance will no longer vent into the old chimney, and the combustion water heater will now vent through an oversized chimney. This oversized chimney can lead to condensation and inadequate draft. The new chimney liner should be sized for the water heater alone, or the water heater in some cases can be vented directly through the wall.

Other Ventilation Concerns

Some fan-assisted, non-condensing furnaces and boilers, installed between 1987 and 1993, may be vented horizontally through high-temperature plastic vent pipe (not PVC pipe, which is safely used in condensing furnaces). This type of venting has been recalled and should be replaced by stainless steel vent pipe. If horizontal venting was used, an additional draft-inducing fan may be needed near the vent outlet to create adequate draft. Floor furnaces may have special venting problems because their vent connector exits the furnace close to the floor and may travel 10 to 30 feet before reaching a chimney. Check to see if this type of venting or the floor furnace itself needs replacement. If you smell gases, you have a venting problem that could affect your health. Contact your local utility or heating contractor to have this venting problem repaired immediately.

Building Biologists: They can tell you exactly (almost) how healthy your home is!

Kenton Shepard (Peak to Prairie Inspection Service) — Wed, 11 Apr 2007 19:41:54 -0500

By Kenton Shepard

Building biology is the study of how buildings impact life. It involves disciplines from a number of areas such as building science, which studies how building react to changes in moisture and temperature levels, Indoor Air Quality, sound building design and construction principles, solar heating and cooling principles, the study of man-made electromagnetic fields and the use of healthy and sustainable matrials in the home. These studies are pursued by following 25 basic principals.

Relatively unknown until rising energy prices began to drive interest in Green Building, building biology is gaining in credibility. The International Institute for Bau-biologie^TM and Ecology, Inc. (IBE), established in Clearwater, Florida in 1987, is a non-profit educational organization dedicated to bringing together the technical expertise, biological understanding and ecological sensitivity to create healthy homes and workplaces.

As a home inspector I find a wide type and number of unhealthy conditions in the homes I inspect. That's why I carry a full-face respirator for crawlspaces and attics. Many of the problems I find may seem insignificant alone, but when enough insignificant concerns are combined, the sum is something to worry about.

There are also a number of concerns which to many people are not real concerns... such as low-level, long term chemical exposure or exposure to environmental hazards with which most people are not familiar... such as histioplasmosis, hantavirus and raccoon roundworm encephilits or high levels of mold spores in indoor air cause by a moisture problem. These are real concerns which have appeared again and again in my healthy home research.

It's an interesting field, still somewhat in it's infancy, but it has a place in a world with an ever-increasing number on people and homes. If you or someone you know has been having reocurring health problems and are having a difficult time nailiing down the cause, you might try calling a bulding biologist in your area.

ROOF CONSIDERATIONS

Kenton Shepard (Peak to Prairie Inspection Service) — Wed, 11 Apr 2007 19:04:47 -0500

By Kenton Shepard

ROOF CONSIDERATIONS

Roof Drainage Systems

Gutters and downspouts which drain roof runoff away from the home are an important part of protecting the foundation. Moisture is the primary cause of foundation problems because it affects the ability of the sol to bear the weight of the building structure.

Roof Flashing

To avoid moisture intrusion of the wall or roof it's important flashing is present and properly installed in the following areas:

Vents

Roofing should extend over the uphill portion of flashing, but on the down hill side flashing should extend out over the roof-covering material.

Drip Edge

Drip edge is a flashing installed along the sloped edges of a roof to protect roof sheathing from moisture. Levels areas of the roof, such along the bottom of a sloped area, are usually protected by the overhang of the roof-covering material.

Roof to Wall Junctions

Step flashing should be used with roofing materials installed in courses such as tiles and shingles.

Chimneys

Chimneys, especially masonry chimneys can be extremely difficult to flash correctly and often require cutting a slot into the chimney to accept counter flashing.

Skylights

Home-made skylight flashing is relatively commend and ineffective

Pitched (sloped) Roof

Roofs with a steeper slope will shed water more quickly than flat or low-slope roofs. In most cases this will lessen the chances for leakage. The exception is situations in which water running down one roof may run up under the shingles of an opposing roof, such as at valleys.

Low slope and flat roofs sometimes allow water to pool. Pooled water will stand until it evaporates, giving moisture more time in which to find an avenue through or around the roof-covering material and underlying membrane.

Type of Roof Covering Materials

Different types of roof-covering materials have different lifespans. Among the roof-covering materials with long lifespans (all things being equal) are...

slate
tile
metal

The lifespans of roof-covering materials are affected by the following:

Material quality
Installation method and quality
Number of existing layers (less is better)
Roof orientation (South-facing roofs deteriorate more quickly)
roof pitch (amount of slope)
Climate (snow, rain, ice, hail, etc.)
Building site (overhanging branches, protection from wind, etc.
shingle color (dark colors absorb more heat)
Elevation (deterioration from ultra violet light)
Roof structure ventilation (cooled roofs last longer)
Quality of maintenance

Indoor Air Quality and Electronic air filters... maybe not such a good idea

Kenton Shepard (Peak to Prairie Inspection Service) — Wed, 11 Apr 2007 18:54:01 -0500

By Kenton Shepard

Although it's hard to make accurate, general statements about electronic air filters since they're not all the same, here are a few concerns...

Probably the main concern is ozone. Although it occurs naturally in the upper atmosphere where it protects living organisms by preventing damaging ultraviolet light from reaching the Earth's surface, too much exposure is toxic to humans. The FDA has set a safe limit of .05 parts per million for human exposure.

Excessive exposure can cause lung damage and especially vulnerable ar those with Asthma, lung disease and impaired imune systems. Hey! It's the same bunch who are vulnerable to problems from exposure to high levels of mold spores in indoor air!

There are air purifying systems which claim to work by producing ozone. Ozone generators should definitely be avoided.

Don't take my word, here's what the EPA has to say...

Some studies show that ozone concentrations produced by ozone generators can exceed health standards even when one follows manufacturer's instructions.

Many factors affect ozone concentrations including the amount of ozone produced by the machine(s), the size of the indoor space, the amount of material in the room with which ozone reacts, the outdoor ozone concentration, and the amount of ventilation. These factors make it difficult to control the ozone concentration in all circumstances.

Available scientific evidence shows that, at concentrations that do not exceed public health standards, ozone is generally ineffective in controlling indoor air pollution.

The concentration of ozone would have to greatly exceed health standards to be effective in removing most indoor air contaminants. In the process of reacting with chemicals indoors, ozone can produce other chemicals that themselves can be irritating and corrosive.
ELECTRONIC AIR FILTERS may or may not put out enough ozone to be harmful, depending on the manufacturer's design. They may require frequent cleaning of the plates, especially in homes with excessive (I don't know, you tell me) tobacco smoke or dust. Some brands may need to have the plates washed as often as every 3 days. In the meantime, they will be noisy, crackling as they pick up dust. More typical might be once every week or two. This does mean that you won't have to pay for new pleated filters 3 or 4 times a year.
The really great solution for those who can afford them are whole-house High Efficiency Particulate Air (HEPA) filters. These filters are usually installed in-line with the duct system and will remove over 99% of airborne particles down to 3 microns, which includes mold spores, so they're very good. Bit pricey though.

Wood discoloration/mold fungi information

Kenton Shepard (Peak to Prairie Inspection Service) — Tue, 10 Apr 2007 15:13:21 -0500

This article is about wood discoloration. Although it uses logs as an example, the information extends to all wood products and it's very instructive about the nature of mold.

Sorry to provide just the link, but for those interested in wood decay and other mold fungi problems, this article is worth investigating, as is the Forintek wesite.

http://www.forintek.ca/public/pdf/fact%20sheets/discolor_eng.1oct02.pdf

I need your opinion on a feature of my website

Kenton Shepard (Peak to Prairie Inspection Service) — Tue, 27 Mar 2007 22:49:09 -0500

I've installed landscape paintings as banners across the tops of most of the pages in my website. I think they look good but whether they look professional or are appropriate is another question. I'd like some opinions please!

If you scroll through the top of the menu there are good ones and also in the GREEN BUILDING section near the bottom of the menu. If I get a positive response I'll install on the other 60 pages.

Thank you

-Kent

Link fixed, thank you Mary!

improving my AR rankings

Kenton Shepard (Peak to Prairie Inspection Service) — Mon, 26 Mar 2007 17:02:46 -0500

State, County and City rankings... is there any way to tell who's ahead of me and to know how to reach the #1 spot in each? What are the citeria?

Insulating Unvented Attics With Spray Foam

Kenton Shepard (Peak to Prairie Inspection Service) — Mon, 26 Mar 2007 16:31:21 -0500

I didn't write this one, but it's good information...

by James Morshead

Written for the Journal of Light Construction

March 2007 issue

Closed-cell polyurethane foam provides the insulation, air barrier, and vapor retarder necessary for an unvented attic assembly

As a general contractor, I was taught that attic and cathedral ceiling assemblies should always be vented. Since then, however, studies have shown that properly designed and installed unvented attic assemblies outperform vented assemblies. They reduce energy loss and protect against rot and mold by preventing moisture from passing through the insulation and condensing on cold surfaces. Although many builders - and even some building inspectors - are unfamiliar with them, unvented assemblies are already part of the 2006 IRC and will soon be allowed by most building codes (see sidebar).

Code Provisions for Unvented Attics

Every state except California and Hawaii has adopted some version of the IRC. And California is expected to adopt it in 2008.

Until recently, the IRC required all attics and enclosed rafter spaces to be vented. But the latest version allows unvented attic assemblies if certain conditions are met.

According to Section R806.4 of the 2006 IRC, unvented assemblies are allowed if "no interior vapor retarders are installed on the ceiling side (attic floor) of the unvented attic assembly" and if "air-impermeable insulation is applied in direct contact with the underside/interior of the structural roof deck."

There is an exception that allows air-permeable insulation (fiberglass and cellulose) to be used in unvented assemblies in certain parts of the South (climate zones 2B and 3B).

It has long been possible to get an unvented assembly approved by the inspector as an "alternate construction method." But once states update their codes to the 2006 IRC, it will no longer be necessary to get special approval for unvented assemblies.

In the meantime, the fact that the 2006 IRC allows unvented assemblies should make it easier to get special approval in states that have adopted earlier versions of the code.

Do not build an unvented attic assembly without first talking to the local building inspector. Unvented assemblies are new in the IRC, and your state might be using an older version of the code. Also, the committee that wrote this section is still working on it, so more changes may be on the way.

I work for a company in Northern California that installs spray polyurethane foam (SPF) insulation, and we are frequently asked to insulate unvented assemblies. Sometimes the building has a flat roof or a cathedral ceiling that would be difficult or impossible to ventilate (Figure 1). In other cases, the existing framing cavities are too shallow to accommodate a sufficient amount of insulation plus a vent space. And occasionally customers request unvented attics because they make the building more comfortable and energy-efficient.

Figure 1. Spray foam is a good choice for roofs that are difficult to vent, like a turret with converging rafters (top) or a flat roof with its rafters hung between flush beams (bottom).

Why Install Roof Venting?
Traditionally, venting has been used to deal with problems that occur when heat or moisture escapes into the attic (Figure 2).

Figure 2. While attic ventilation can mitigate problems caused by ineffective insulation or leaky air or vapor retarders, a better approach is to build the attic as an unvented assembly. The foam insulation used for unvented attics stops air movement and with it the transport of moisture. Any hvac equipment located in the attic is within the conditioned shell of the house, which also cuts energy losses.

In cold climates, the escaping heat can cause ice dams by melting the snow on the roof. Venting the space above the insulation helps keep the roof cool by carrying this heat away. If moisture enters the attic through the ceiling (usually as an air leak), the vents are supposed to allow it to exit before it condenses on something cold.

However, ventilating above fiber insulation comes with an energy penalty. Fiber insulation is designed to be enclosed in an airtight cavity. When air flows over and through fiber insulation, there is a substantial loss of thermal performance.

Also, most hvac ducts and air handlers leak to some degree, so when these are installed in vented attics, conditioned air is lost to the exterior. And because vented attics are subject to extreme high and low temperatures, additional energy is lost through the thin insulation on the hvac equipment.

In cooling climates, venting the attic can bring humid outdoor air into contact with attic ductwork. If the ducts are not properly insulated, they can be cold enough to cause condensation.

Venting and shingle temperature. It's a common misconception that code-required venting significantly lowers the summer temperature of the roof surface. In fact, tests have shown that it lowers the surface temperature of asphalt shingles by at most about 5°F.

For many years, roofing manufacturers required that shingles be installed over vented substrates, but today, several companies - including Elk and CertainTeed - will guarantee shingles installed over properly constructed unvented roofs.

How Unvented Assemblies Work
A properly constructed unvented attic is immune to the moisture problems that occur in vented assemblies and is much more likely to be energy-efficient.

In an unvented assembly, anything below the insulation - including an attic - is considered conditioned space. Turning the attic into conditioned space saves energy; if heat or air escapes from the hvac equipment, it remains within the conditioned space (Figure 3).

Figure 3. The ducts visible in this unvented attic will be concealed after drywall is installed. But because they are in conditioned space, they won't be subject to the extremes of temperature typical of attics.

If enough energy is saved in this manner, the hvac system can actually be downsized, reducing installation and operating costs.

A number of insulation materials can be used in an unvented assembly, but the one with the greatest applicabil-
ity across the country is SPF. It's an extremely effective insulation and air barrier all in one, and since it's spray-applied, it conforms to irregular shapes that otherwise might be difficult to insulate and seal (Figure 4).

Figure 4. This barrel ceiling (top) would be difficult to insulate and seal with traditional materials. It's an ideal candidate for spray foam, which conforms to its irregular surfaces (bottom).

Despite the multiple brands of SPF, there are only two main kinds: open-cell foam and closed-cell foam. Chemically, all brands are nearly identical - contrary to some advertising claims - and contain about the same proportion of agriculturally derived resin from corn, sugar beets, sugarcane, or soybeans. None of the spray foams contain formaldehyde or use toxic or ozone-depleting blowing agents.

The important differences between products have to do with density, R-value, and permeability.

Open-cell foam. The typical open-cell foam weighs 0.5 pound per cubic foot and has an insulation value of R-3.5 per inch of thickness. This type of foam is relatively permeable; at 5 inches thick it is rated at about 10 perms. Open-cell foam is an air barrier but not a vapor retarder.

When sprayed, open-cell foam expands to about 100 times its liquid volume, so it usually has to be trimmed flush to the framing. Fortunately, it's soft and easy to trim.

Closed-cell foam is denser and less permeable than open-cell material. The typical closed-cell foam weighs 2.0 pounds per cubic foot and provides R-6.6 per inch of thickness.

When sprayed, closed-cell foam expands from 30 to 50 times its liquid volume, making it easy to apply without completely filling the framing bay. If the bay must be filled completely, the applicator can overfill it and then trim off the excess.

Trimming closed-cell foam is not as easy as trimming the open-cell material, but it can be done.

Advantages of Closed-Cell Foam
Both types of SPF are excellent insulation materials, but our company uses closed-cell material in unvented assemblies because we think it provides the best overall performance. With it, we can pack more R-value into a small space, which is helpful when the existing rafter bays are shallow; for example, we can get R-30 into a 41/2-inch space.

In our climate zone, it's important to avoid excessive vapor diffusion, and we think the best way to do this is to use closed-cell foam. One of the great benefits of closed-cell foam is that if you install it to a thickness of at least 2 to 2 1/2 inches, it will have a permeance of 1.0 perm or less.

This means that in addition to being an air barrier, closed-cell foam is a vapor retarder. It's actually a vapor retarder from both sides, so it ends the debate about which side of the insulation to put the vapor retarder on in climates where interiors are both heated and cooled.

Some companies that make both open-cell and closed-cell foam advise insulation contractors not to use the open-cell material in unvented assemblies - or to do it only in certain climates where vapor diffusion will not be a problem.

In conditions of extreme vapor drive - an indoor pool or spa, for instance - it may be necessary to further reduce the permeability of closed-cell foam by coating it with a spray-applied liquid vapor barrier.

Cathedral Ceilings
In a vented cathedral ceiling, the insulation is in contact with the back of the drywall and there's an air gap (the venting space) above. But in an unvented assembly, the insulation must be against the bottom of the sheathing.

Sometimes, if the rafter bays are unusually shallow, we have to fill them all the way up with closed-cell foam (Figure 5). But because this type of foam has such a high R-value, in most cases we have to fill the cavities only partway.

Figure 5. Open-cell foam, which expands to about 100 times its liquid volume, typically has to be trimmed flush to framing members - an easy task, since the foam is so soft. Because of its lower expansion rate and higher R-value per inch, closed-cell foam doesn't usually have to be trimmed. When it does, as in this shallow rafter bay (top), the author's crew uses a scraper - in this case a horse curry comb - to clean the framing in preparation for drywall (bottom).

Contractors often ask about the air space below the foam; most were taught that it's bad to leave an air space below insulation. This is true of fiber insulations because convection currents can form in gaps and degrade the insulation's thermal performance. But it is not true of foam, which can't be infiltrated and is relatively unaffected by surrounding air currents.

Any space left below the foam is considered conditioned space (Figure 6).

Figure 6. Fiberglass and cellulose insulation are usually installed in contact with the back of the drywall; the concern is that leaving a space there allows convective air currents to degrade the insulation's thermal performance. Because closed-cell foam is unaffected by air movement, the space between it and the drywall is not a problem.

Dealing With Can Lights
It's easier and more energy-efficient to build a cathedral ceiling as an unvented assembly, but dealing with recessed light fixtures can be a real challenge.

There are two issues: how to insulate and seal the area above the fixture, and how to provide enough space around it so it doesn't overheat. Even if the fixture is an IC unit, you can't embed it in foam.

Insulating above. If we're lucky, there will be room to spray a full thickness of foam above the fixture and still maintain the desired 2 to 3 inches of clearance between foam and fixture.

If there isn't enough space or access to spray above a fixture, we sometimes install a piece of nonperforated foil-faced rigid foam above it instead. Before spraying, we mask the fixture to keep it clean, then create an airtight seal by lapping the SPF onto the rigid foam (Figure 7). If the rigid foam butts to framing, we caulk that joint with polyurethane sealant.

Figure 7. Code requires that a space be left between can lights - even IC-rated cans - and spray foam insulation. In shallow bays, the author's crew installs foil-faced rigid foam above fixtures and creates a seal by lapping the spray foam onto it (top). An alternate method, which may soon be required in California, is to isolate fixtures from the foam by installing them in metal boxes (bottom).

Clearances. Few building codes contain specific requirements about clearances between foam and can lights, so it's a good idea to talk to the building inspector about the issue. SPF is such a good insulator it can cause a fixture to overheat, tripping the temperature-limit switch and cutting power to the light. Excess heat could also damage the wire sheathing or even the foam itself.

In California, new code provisions are being developed that will require builders to take one of three measures with recessed lights: leave 3 inches of clearance around a fixture, box around it, or wrap it with 2 inches of mineral fiber. A 3-inch clearance is already required around hot appliance vents.

SPF is compatible with PVC and CPVC, so it's okay to spray it on Romex, PVC pipe, and CPVC sprinkler pipe.

Air Sealing
Any surface we spray will be sealed against the movement of air, but there are always some surfaces we can't spray.

For example, the gaps between doubled-up framing members are too small to spray with foam, yet a significant amount of air can leak through at these spots. It's best to seal these joints during framing by installing compressible foam gaskets between the members. If that isn't done, you can caulk the joints after the foam is installed.

When the gaps are too wide for caulk, we fill them with foam from a can. The canned foam should be the low-expansion type; it contains more closed cells than the high-expansion material. We stay away from the latex foams because they're very permeable.

Fire Resistance
When the unvented assembly is a cathedral ceiling, the foam will be covered with drywall, which is a code-approved thermal barrier. In an attic, though, the rafter bays are not normally covered by drywall, so the issue of fire-resistance comes into play (Figure 8).

Figure 8. When insulating an unvented roof assembly, the author prefers closed-cell to open-cell foam because it's both an air barrier and a vapor retarder. To finish an unvented cathedral ceiling insulated with closed-cell foam, most codes require a layer of 1/2-inch drywall or an equivalent thermal barrier (top). Depending on local code, the spray foam in an unvented, or "cathedralized," attic (bottom) may not require drywall covering unless the area is accessible for servicing equipment. In some cases, the foam may have to be sprayed with an intumescent coating.

This can be a gray area in the code, so be sure to check with your building department before building an unvented attic space. Most codes state that if the attic is accessible for the service of utilities, the foam must be covered with an ignition barrier. Certain water-based intumescent coatings qualify as ignition barriers.

If the attic area is not accessible or is not "accessed for the service of utilities," it may be possible to leave the SPF exposed. Many contractors are confused about how to treat this enclosed attic space. Providing access through a ceiling hatch is okay but not necessary; venting to the room below is prohibited by the fire code.

Other Issues
Unlike fiber insulation, which can be blown through a hose or stuffed into hard-to-reach areas, SPF can't be installed without sufficient access. The applicator must be able to get close enough to the sheathing to spray from 16 to 24 inches away - and do it from pretty much straight on.

Cost. In our area, the installed cost of an average-size closed-cell foam insulation project is between $1.10 and $1.40 per board foot of material.

For R-30, that comes to about $5 per square foot of roof area. That's more than other insulation materials would cost, but not much more if you factor in all of SPF's advantages - future energy savings, increased comfort and moisture control, the greater design flexibility that comes with being able to fit the necessary R-value into small framing cavities, and the possibility that the mechanical system can be downsized.

James Morshead is senior project manager and technical director for American Services Co. in Dublin, Calif.

Home Inspection Structural Problems: Recommend a Contractor or Engineer?

Kenton Shepard (Peak to Prairie Inspection Service) — Mon, 26 Mar 2007 15:52:02 -0500

By Kenton Shepard

Once structural problems are found during the home inspection, the inspector will be faced with the decision of whether to recommend a qualified contractor or a structural or soils engineer. The agent and the client may or may not agree with with the inspector's decision.

The advantage to recommending the engineer is that for the inspector, it's safe. The engineer will assume all the liability. For the client, it's safe- the client will get (arguably) the professional most qualified to identify the problem and recommend a solution.

The disadvantages are primarily disadvantages for the client. Good structural engineers are busy and may not be able to respond quickly. They are also expensive and although they may identify the problem, they are most likely to recommend a solution which protects them from liability and cost will probably not be their main consideration.

The advantage to recommending a qualified contractor is that they will often evaluate the problem, issue a recommendation and give you a price for correction... all for free! With an engineer, the client only gets two out of three and pays a lot of money for them.

There are very experienced contractors available who are perfectly qualified to evaluate problems which don't require engineering calculations or whose experience allows them to be comfortable making decisions in situations which might ordinarily require engineering calculations.

The word "qualified" is very important in picking a contractor. This is not a situation in which someone should throw a dart at the yellow pages. Unscrupulous contractors may invent problems where none exist because they want the work or because they don't understand what they're looking at. Homes are complicated collections of systems and components. Unqualified contractors may make recommendations which address the symptoms of a problem, but not the fundamental problem itself.

I routinely recommend a foundation contractor who's been in the same business for 40 years and who has an engineer on his staff.

When I find roof trusses which have been cut and it appears to me that the alterations were not performed according to engineered drawings, I always recommend a structural engineer.

The final choice in deciding whether to recommend a contractor or engineer will depend on the nature of the problem and the relationships and confidence the inspector, client or agent has with local contractors.

Hot/Hot	8.3	66	Hot/Hot	.329	20
Hot/Warm	6.3	50	Hot/Warm	.247	15
Hot/Cold	4.3	34	Hot/Cold	.164	10
Warm/Warm	4.3	34	Warm/Warm	.164	10
Warm/Cold	2.3	18	Warm/Cold	.082	5
Cold/Cold	0.4	3	Cold/Cold	---	3

Hot/Hot	6.5	52	Hot/Hot	.248	15
Hot/Warm	4.9	39	Hot/Warm	.186	10
Hot/Cold	4.3	27	Hot/Cold	.124	7
Warm/Warm	3.4	27	Warm/Warm	.124	7
Warm/Cold	1.9	15	Warm/Cold	.062	4
Cold/Cold	0.4	3	Cold/Cold	---	3

Appliance	Temp.	Time	Energy	Cost(1)
Electric oven	350ºF	1 hr.	2.0 kWh	16¢
Convection oven (elec.)	325º	45 min.	1.39 kWh	11¢
Gas oven	350º	1 hr.	.112 therm	7¢
Frying pan	420º	1 hr.	.9 kWh	7¢
Toaster oven	425º	50 min.	.95 kWh	8¢
Crockpot	200º	7 hrs.	.7 kWh	6¢
Microwave oven	"High"	15 min.	.36 kWh	3¢

Household Product	Typical Wattage	Typical Usage	Cost Per year @ $.76/kWh
Bathroom fan	60	1hr/day	$1.66
Black & white television	556	0.6 hrs/day	9.15
Bottled water dispenser - (hot & cold)	65	24 hrs/day- 203 kWh/hr	15.43
Ceiling fan	23	hrs/day-5mos/yr	2.22
Clock	860	24 hrs/day	1.33
Coffee maker	200	2 times/day	10.16
Color television	200	6 hrs/day	33.29
Computer	250	2 hrs/day	11.10
Dehumidifier	200	7 hrs/day-5 mos/yr	19.95
Electric blanket	200	4 hrs/day-5 mos/yr	9.12
Electric mower	900	12 hrs/yr	0.82
Furnace fan	300	1600 hrs/yr	35.36
Garbage disposal	450	22 hrs/yr	0.75
Humidifier	170	360 hrs/yr	4.66
Instant hot water	7000	2 hrs/wk	55.33
Iron	1100	4 hrs/mo	4.01
Spa/hot tub (electric)	2000	3 hrs/day	166.44
Sump/sewage pump	500	80 hrs/yr	3.04
Toaster	1100	2 hrs/mo	2.03
Toaster oven	1500	4 hrs/mo	5.47
VCR	20	4 hrs/day	2.22
Waterbed heater	350	7 hrs/day	67.96
Well pump	750	1.5 hrs/day	31.21
Whole-house fan	375	6 hrs/day-5 mos/yr	25.65
Window fan	200	3 hrs/day-5 mos/yr	6.84