When it comes to insulating your home, you’ve probably heard the old adage that you can’t make a house too tight because every house needs to “breathe.” Kind of a funny way of saying that the air in your home becomes more stuffy and stagnant the tighter it becomes. This stuffiness effect is in fact due to every house actually needing a proper air exchange (the breathing metaphor), which is why we don’t typically build our homes the same way we build refrigerators. A refrigerator is well insulated, sealed tight against its surrounding environment, and would basically kill us unless outside air was piped in from the outside. Unfortunately, this constant breath we and our homes need, limits how tight we can actually make our living space, which in turn limits how energy efficient we can actually become. Or does it?
The more control you have with your indoor air against its surrounding environment, the more energy efficient your indoor environment becomes, the more durable your house becomes, and the potentially the more healthy the inhabitants become. But before we can achieve an extremely tight house, we must first take a look at the missing link in most efficiency upgrade plans: ventilation. That’s right, we must purposely create new holes in our house that we can mechanically control. Then, we eliminate all the old holes in the house where outside air would either infiltrate in or out of the structure. The difference, however, between these new holes and old holes, is that we can control the airflow with the new ones. We can temper the air, so we’re not dumping 10 degree air in our 65 degree house. We can filter our air to eliminate dust and other harmful allergens and pollutants from entering our indoor environment. And we can exchange the humidity, allowing us to eliminate mold in wet climates or capture more humidity in dry climates. We can even set how much air we need or want depending on the type of day we’re experiencing.
Without mechanical ventilation, the holes we have in our house are dumb. They bring in the extreme opposite of what we want our indoor air to be. In the summer they let in hot, humid air into our dry, cool indoor climate. In the summer, they do the opposite, they bring cold air into our warm environment. And if this weren’t bad enough, most of the holes in our house are located in places we typically wouldn’t want to be breathing. Places like moldy crawl spaces, or fiberglass-filled attics, even CO vents from our furnace and hot water heater. In fact, very little of our air exchange comes from windows and doors, and unfortunately this is a place we’re encouraged to seal first, which totally eliminates the only true “fresh” air source we have in the house, leaving only extremely polluted air to enter.
There is a solution to all this mess though. It’s called an Energy Recovery Ventilator, or ERV. The system mechanically creates an air exchange in your home, which means you can eliminate all the other dumb holes in the house. And when I say eliminate, I mean try and seal up the entire structure. Seal the attic by pulling out all the old insulation and laying down a layer of polyurethane air sealant before blowing in new insulation. Seal the crawl space by sealing and insulating the concrete walls and sealing the dirt floor. And seal your gas appliances, like your furnace and hot water heater, with direct vent appliances which get their combustion air from outside. Then you turn on your ERV, and you’ll find you can almost heat your house from cooking a tv dinner and turning on the television (both of these generate heat which are usually lost from excessive infiltration). The ERV will act as an open window in your home with all the benefits and none of the drawbacks, it will bring in fresh clean outside air 24-hours a day, 365 days a year, tempering, filtering, and exchanging your stuffy, polluted inside air with fresh, clean outside air (or at least fresh and clean once it passes through the HEPA filter). Then, and only then, will your air be clean and your home energy efficient.
All of this comes down to breathing and control, and if you’re in yoga, or are a swimmer, or a runner, or a zen master, you know that controlling your breath is the path to a healthier and better you. The same is true for your home. But without control you’re left with bad air constantly infiltrating in. Air that you have to pay the utility company to heat, which brings in the dust you constantly have to clean up, and produces the mold you seem never to be able to get rid of. All of these are symptoms which say our home’s air is out of control, which can lead to not only a sick house, but an unhealthy you. Yes, a house, like any living thing, needs to breath, but how a house takes its next breath is totally up to you.
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