Monday, May 4th, 2020 by Erin Dougherty
Under insulated attics are a huge source of energy loss and leaves homeowners feeling uncomfortable.
In the summer, the sun beats down on your roof, heating your attic well beyond outside temperatures. In turn, your attic heats the ceiling, which radiates down into the rooms below. This means rooms below your attic become uncomfortable, maybe even too hot to use and seem impossible to cool down.
What if your HVAC is in the attic too? Then your duct lines are being baked in the attic, warming up to over 100 degrees. When you pump cold air through them, the ducts heat the cold air up. Now, you’re sending significantly warmer air into rooms you’re trying to cool down! Your air conditioning runs more, putting wear and tear on your unit and increasing your energy bills and you are still uncomfortable.
In the winter, your attic is the same temperature as it is outside. Because our homes are naturally leaky, the warm air produced by your heating system is rising through your home and meeting the cold ceiling. The air is cooled down and falls. This cycle is called convective looping and can make rooms feel drafty and hard to heat and cool.
With ductwork in the attic, the lines cool to the same temperature and suck the heat out of the conditioned air you are trying to send to the rooms below. We’re now trying to warm cold rooms with cool air. It leaves these rooms too cold and uncomfortable; we use space heaters to try and make up the difference, but ultimately, we’re spending more money to be uncomfortable.
The solution to uncomfortable rooms, air loss, and high energy bills? Proper insulation and air sealing in the attic.
R-value is an insulation’s resistance to heat transfer. Too little insulation refers to a low R-vale. The lower the R-value, the more heat transfers through the material to the rooms were trying to condition. Adding additional insulation and increasing the R-value will reduce the transfer of heat. This means in the summer, less heat from the attic will transfer to the ceiling and radiate to the rooms below. In the winter, the ceiling will not get as cold, sucking the heat from the air.
However, just insulating isn’t enough. Air sealing your attic is a big piece of ensuring that your home is not only comfortable but energy efficient. Building Science and The Stack Effect tell us that conditioned air escapes through gaps in our home’s construction. These gaps include top plates, bath fans, recessed lighting, and utility penetrations. If we do not stop the air from escaping, we will continue to replace it with unconditioned air at the bottom of the home, leaving us with high energy bills, poor indoor air quality, drafts, and uncomfortable rooms.
Air sealing all the holes in the attic will allow us to greatly reduce the amount of air escaping out of the top of the home, keeping more of the air you paid to heat and cool inside your living space, and therefore making your home more comfortable and energy-efficient.