Monday, November 2nd, 2020 by Ashley Walther
What is air sealing?
When people realize their house is too cold in the winter and too hot in the summer, most of them think that the solution is to add more insulation. However, insulation only addresses one way that air moves. Insulation will slow heat transmission, meaning it does its best to keep warm or conditioned air from escaping the home. Think of it like wearing a sweater in cold weather; it will keep you warm but it’s not airtight so you still lose body heat through the sweater and cold air from the outside can still get through and make you cold. Air sealing is like adding a windbreaker over that sweater. It’s an added layer of protection that further prevents heat from escaping by ‘sealing’ leakage points. Air sealing is an important solution for homes that have existing insulation but are still facing comfort and efficiency issues.
How does air sealing work?
Aire sealing reduces the stack effect in your home. The stack effect happens in every home all year round but the easiest way to understand it is through the winter scenario. As you heat your home, the warm air rises to the highest point and easily escapes through unsealed penetration points (usually found in the attic). These points can be bath fans, ceiling registers, recessed lights, and top plates (the top part of walls that have gaps alongside them where the drywall meets). Heated air moves upwards and can escape through these leakage points and into the attic.
Heated air also escapes through open chases. A chase is like an elevator shaft that runs up from the basement to the attic. Usually, it is there to run the chimney for the furnace/water heater in the lower level up to the roof. Sometimes it can be for duct work to reach the upper floors. This is a direct connection from the attic to your home and the largest holes you could have in the attic floor.
A reversed example is what happens in the summer time. Because hot air always moves towards colder areas, you will have hot, humid summer air entering your home through these leakage points in the attic. This can cause your HVAC system to run 24/7 to overcompensate for the hot air that is leaking in.
Air sealing reduces the number of air exchanges, keeping the conditioned air you’ve paid for in the home. Sealing these leakage points also prevents allergens and mold spores from entering the air in the home and controls the humidity level in the home during warmer months. It also has a side benefit of requiring no maintenance once it is installed. Air sealing is a great solution for homeowners looking for year-round comfort and energy efficiency, without having to keep adding insulation.