Air Sealing
Thursday, February 24, 2011: Updated Sunday April 14, 2013
Getting solar panels will reduce/remove your electric bill but they won't make your house any more energy efficient. They won't do a thing for the gas bill either. Or the kids Orthodontia.
I recently had an energy audit from a company called "Green Label Solutions".
They came over on a Friday morning and for 2 hours took thermal images of my entire home.
They measured everything from the flame in my gas furnace to the ice cubes in my freezer.
They suggested I have the following things done to my house:
- Seal all the air leaks around my windows and doors.
- Put foam pads behind all exterior wall plates.
- Put in more baffles for my soffit vents in the attic.
Why don't home builders spend an extra $2 per windows and install them correctly? Insulate and air seal please. Also, why put in an energy star vinyl basement window only to have them set into a steel frame? That defeats the whole reason for having a vinyl casement in the first place. Now I have Energy Star windows being nulled out by thermally conductive casings.
There is nothing I can do about my 7 basement windows without first removing them and re-doing the entire install. What a pain.
While I'm on the topic, I have a gripe about Energy Star Windows. In order to qualify for energy star, they must be able to leak less than 0.3 cubic feet of air per minute. This spec is like an ice cream shop advertising that their milk shakes are guaranteed to contain less than 0.3 cups of poop per serving.
It is beyond me why they continue to produce such windows and call them energy star. Give me one that carries a zero cubic feet/min leakage rate please!
Update 3/12/2012:
It has been over 1 year since I had Green Label Solutions come out and air-seal my home. I went back and compared my last 3 months worth of natural gas bills to the same 3 months the year before.
Not only were there significant savings on my gas bill, my electric bill went down too, especially in the summer time when the Central AC is running.
The following chart shows my electric usage (not my net usage as my solar panels offset nearly all consumption) the season before and after air-sealing my house.
July of 2011 was unseasonably hot and humid. I assume this is why the savings were not as significant that month. In 2011, I installed a ceiling fan in the living room and added a misting system
to the Central AC. These additional improvements in efficiency skew the data a bit. I assume that air-sealing alone contributes to an 18-20% efficiency improvement while the other improvements make up the rest.
The additional shading cast by the solar panels on my roof reduce the home's air conditioning needs by an estimated 5%.
Update 2/18/2013:
We have replaced our home's furnace and central air conditioner with a ground-loop heat pump. I will not be able to report on any long-term damage caused by misting the cooling coils on the central AC. Upon removing the A/C coil, it had some evidence of hard water deposits (probably from before the lines were fed with soft water) but was still in good working condition. I resold it to recoup some of the costs of the Geothermal system.