A home energy audit in Salt Lake City, Utah that we did yesterday was kind of interesting. The home was built in the mid 1970's and had new windows and doors and was caulked and sealed up very well. I was impressed with just how well this home was insulated and especially how weather tight the ceilings and walls were. I started the energy audit at the front entry and placed the blower door in the garage entry door.
An energy audit in simple terms is when we close up all of the intentional openings and depressurize the home with a calibrated blower creating a negative pressure. Since the inside of the home is at a lower pressure than the outside, any place where "unconditioned" outside air can infiltrate into the home is quickly pinpointed out with infrared thermal imaging and included in the energy audit report.
This home was "tight" and was only flowing around 2,850 cfm at .020 water column inches inside pressure. However once I went into the basement living area I noticed the fireplace bricks were whistling. Actually we all though it was funny. After the home owner seals up these openings this older home will be as airtight as a new energy star home.
In the infrared photos - the blue areas is cold outside air entering the home around the brick chimney.
For more information: www.utahenergyaudit.com