When anyone thinks about weatherizing and “tightening” their home, their thoughts typically turn immediately to new windows, and perhaps doors. But, is this really the best, most efficient way to weatherize your home?
In actuality, most homes lose the majority of their warm/or cool air through smaller, less obvious routes. Foundation cracks, chases (attics), all the various penetrations that a house has for utilities (such as for plumbing) are small areas where heat loss happens. Sealing these routes and adding insulation is the most cost-efficient method to energy conservation.
How do you know if your house is leaky? A blower-door test is the best way. During a blower door test, one of your exterior doors will be opened and the other exterior doors and windows will be closed. Interior doors will be opened and woodstoves and fireplaces covered, and dampers closed.
The opening where the door has been removed is then fitted with a blower-door apparatus that utilizes a calibrated fan. The fan speed is slowly increased, and air is drawn out of the house until the pressure inside the house is reduced, relative to the pressure outside. Then the fun begins.
Air-flow is measured in either Cubic Feet per Minute (cfm) or in Air Changes per Hour (ach). Typically, most technicians work with cfm measurements. The next question is, what’s a good rate of air movement and what’s a bad one?
Think about it. To heat, or cool your home, you are heating or cooling the air inside the house. If you set your thermostat at 70°, and the outside air is 20°, then any air being drawn into the house will need to be heated up by 50°. Conversely, the air inside the house, which you have paid to heat up, is leaking out into the cold.
A leaky house can lose so much heat, that it is equivalent to leaving a window wide-open in the dead of winter! Think of that. This allows all that hot air, that you paid to heat up, to just flow outside.
Literally, every minute you hesitate, you’re paying to heat (or cool) air that is simply leaking to the outside. Before you waste more money, contact a weatherization professional and ask them to perform a blower door test and find out where you can save money.