When air sealing we use what’s called a Blower Door Test to determine air leakage in a home.
With air sealing, air penetration can explain the loss of 30-40 percent or more of a home’s heating/cooling costs. It can cause also cause more problems with moisture, noise, dust, indoor air quality, and pests. Proper air sealing can cut down on these specific issues to reduce heating/cooling costs.
Air Leakage is when outside, uncontrolled air enters through cracks and openings into the conditioned air existing in your home. Air Leakage can also contribute to moisture problems that can affect the health of those living in the home, and the durability to the home structure. It is recommended that you reduce air leakage as much as possible and to provide controlled ventilation as needed. (Do not rely on air leakage as a means for air ventilation).
When looking at air sealing generally, ceilings, walls, and floor/foundation separate the inside conditioned space from the outside or unconditioned space forming both the air barrier and the thermal barrier for the house. A visual inspection is used to verify the thermal barrier, but a Blower Door Test is used to measure a home’s airflow and can help find leakage sites. Reducing the amount of air leaking in and out of your home is a cost-effective way to cut cooling and heating costs, improve the life of your home, increase comfort, and create a healthier indoor environment.
To effectively air seal we use caulking and weatherstripping. Caulk is usually used for cracks and openings that are stationary in the home, such as windows and door frames; while weatherstripping is used to seal moving areas such as doors and windows which open and close.
Testing your home for air tightness can help to identify where leakage is occurring. Once discovered, a determination can be made as to what appropriate steps are necessary to remedy the air leakage. Air leaks can be found, but are not limited to, areas where plumbing, electrical, and ducting come through walls, floors, ceilings, windows, doors, window and door trim, can lights and soffits above cabinets. Also, air sealing around the chimney, furnace and gas water heater vents can be areas of leakage.