Insulation and Air Sealing
Enhancing your home’s energy efficiency can seem like a tricky process for many Seattle-area homeowners. After all, there are a variety of different directions to go in when choosing home performance upgrades, some of which will likely be more suitable for your home than others. Insulation and air sealing can make the biggest difference to the comfort of a home.
Insulation: A Sweater for Your Home
It’s no secret that the winter chill can make it difficult to properly condition a home. This is especially true if your home isn’t properly insulated. Insulation products act as a sweater to slow heat transfer across the shell of the home (ceiling, walls, and floor) to help keep heat in in winter and heat out in summer. Most homes have low levels of insulation, or no insulation at all.
Air Sealing: The All-Important Windbreaker
While insulation acts as a sweater for your home, a sweater itself isn’t enough to keep the cold at bay if there is any air movement. Air sealing is the “windbreaker” over the sweater. Here in the Northwest, we know all about layering. The air sealing process is a matter of locating the holes, and even potential holes, and sealing them up. When combined with the right insulation, air sealing makes all the difference in the world in terms of your home’s comfort, heating and cooling bills, and energy efficiency.
FAQ 1: I’ve heard that homes can be sealed too tightly, which can create indoor air pollution and cause moisture build up in the walls and attic. Isn’t that a problem?
A: Yup, it can be. There are decades of building science research that have taught us how to do it right so we don’t trap moisture and do allow for drying if moisture find its way in. We know how to ventilate to prevent indoor air pollution, how to monitor for gases, and how to locate and eliminate pollution sources. If energy were free and there was no such thing as global warming, we’d just put in huge furnaces and leave the windows open all time.
FAQ 2: Do what? Seal and ventilate? Um, why don’t we just leave well enough alone? My house is old, it was built to breath, and it’s in very healthy condition.
A: That’s true, your house may be very healthy. The wood may be in excellent condition in large part because your home has been breathing for the last 100 years. A couple problems here: energy is not to be wasted anymore, and the breathing your house does is actually very erratic. The breathing it does is driven by temperature differences between outside and inside air, so it most likely over ventilating in the winter when the differences are greatest. Summer is not usually an issue in our climate because it’s not so hot out usually that we can’t open windows. So the home is hyperventilating in on the coldest days, then not enough at other times. The solution is to seal it up, very carefully so as not to trap moisture, and then to control the ventilation rate mechanically to get the right amount of ventilation all the time.