Two old saws turn up when I speak to homeowners at every home energy audit I do. And I’m not talking about your grandfather’s hand saw that cuts on the push stroke instead of on the pull. But it’s my duty to educate homeowners, so I proceed.
The first old saw is the almost universal, “I know my windows are leaky.”
I ask, “Does heat rise?” Most homeowners look at me as if I were out of my mind and answer with a condescending version of “Yes.” I freely confess that it’s a sucker punch.
“Sorry,” I reply. “Heat does not rise. Warm air rises. Heat goes from warmer to colder, regardless of what direction it must travel to do so.”
For those who get it, we go on a merry journey through conduction, convection, and radiation; air pressure in buildings; safe combustion appliances; and how their homes can be safer, more comfortable, more energy-efficient, and more durable. On a good day, a contract is signed for improvements and everybody wins.
Somewhere along the line, the second old saw rears its ugly head: “But houses have to breathe!”
Ummm … no. People have to breathe. Houses are made of inanimate stuff. They just sit there until we screw them up.
This occurs rapidly if we build them poorly out of cheap materials or slowly if we build them well out of good materials. Either way, the real enemy is water in vapor, liquid, or solid form.
Breathing is about obtaining the right mixture of gases in air or water (for sea creatures) to support life. People and other animals are combustion appliances, and they have a lot more in common with furnaces, water heaters, cars, and motorcycles than they do with houses. All of the above need a steady supply of a fluid (air or water) to keep them running. Buildings just sit there.
More than 10,000 homes across the U.S. have earned LEED certification through the LEED for Homes program, according to the U.S. Green Building Council as of April 2011. Source: U.S. Green Building Council
Houses don’t need anything but thoughtful use and regular maintenance. They are the equivalent of a cave with doors, windows, and a widescreen TV. Caves don’t need to breathe to be durable, and houses would be perfectly happy and durable in a vacuum.
You could take your house and wrap it completely in plastic wrap like a big, stinky (but delicious) onion that you want to save in the fridge. Just as you don’t dry out the onion for storage, neither do you dry out the house. Nor do you soak the onion, so neither should you soak the house. Thirty percent to 40% humidity is about right.
Now put the house someplace where the sun can’t beat down on it and the temperature is moderate — say 68° F — and go away for a while. You can come back in two days, two weeks, two years, or two centuries and the house will be right there, ready to be unwrapped and moved back into. It wasn’t bothered at all by not breathing. Try that with your mother-in-law.
So forget about the house breathing and concentrate instead on fresh air for you and the cat or dog. In fact, let’s make the place as tight as possible and provide fresh air mechanically. We don’t want to bring the outside inside; we want to keep the outside outside. None of this is in any way inconsistent with the business of remodeling. Building performance should be a basic component of remodeling, right there alongside the paint color fans, whiz-bang faucets, and breathtaking door hardware.
When all is said and done and time lumbers on into the future, the building performance component may turn out to be the most important part of all.
—Ed Voytovich, a 40-year remodeling veteran, is BPI-certified, a HERS Rater, and a licensed home inspector in New York state. He works with Home Energy Performance by Halco. Reach him at ed@TheBER.com.