We've all had them, done them, bad jobs. You might even find a song or three about crumby jobs. It's said they build character, one must "pay their dues" to get ahead. That may be true. Yet no matter how you phrase it, no matter how play it, it just sucks!
Take for example this furnace install. Bad work, work that is done without care or in this instance without regard for the safety of the occupants of the house is not just bad, it's criminal.
Now you might be looking at this furnace and asking, What exactly is wrong? I would absolutely expect most people, homeowners, not to know. Which is exactly why, the company, the people that you hire have been give a huge amount of trust to do the job correctly and safely.
The biggest problem with this install is that the system lacks return ducts. The air filter at the return plenum at the bottom of the unit is "filtering" air taken directly from the mechanical room, not the living space. You will also notice another heating system, a gas boiler, sticking into the picture at the right. Also present in this cozy little room are three gas fired water heaters. All four of these appliances are atmospherically vented, meaning that the gases from combustion vent naturally, without powered assistance.
When a furnace fires up, the burner warms up the heat exchanger, and then the blower inside the furnace, just behind that air filter, begins to spin pushing warm air into the house. A furnace fan, a blower, is designed to move a lot of air. Anyone who has felt the warm air blowing from a single supply duct will understand the force is strong. Now multiply that by 10 or more and you can understand the force of the air being pushed throughout the ducts in a forced air system.
What blows must also suck. In other words, you can not blow air into a closed space, the force of resistance will stop the flow. Therefore a return duct is necessary to create a recirculating system.
This is efficient. This is safe.
However placing the return in the same room with the furnace is strictly verboten. That same duct also can not be within 10 feet of any atmospherically vented appliance.
Why?
Because all that sucking the furnace fan does creates a huge vacuum in the room if so installed. It vacuums the air from the room. It also vacuums the combustion gases from the atmospherically vented appliances. Where do those combustion gases then end up? They are very efficiently distributed through out the living space through the supply ducts.
The picture of the top of one of the three water heaters near the furnace shows that severe back venting has been occurring, judging from the condition, for a very long time. Notice the melted plastic rings around the pipes.
While some jobs may be bad, when it comes to the job of a furnace, all the blowing and sucking must be done in a harmonious, and above all, safe equilibrium.
Comments(27)