Thursday, February 18, 2010

Green Thoughts: Duct Sealing - The Fight To Keep Your Air

--Duct Sealing

So once you have taken an energy audit and sealed the leaks in your attic and building shell, you want to make sure that you are getting clean conditioned air from your heater or air conditioning, depending on the season. Heating your home is extremely important in the frigid winter like it is now, just ask anyone who lost power during the recent snowmageddon in the mid-atlantic region. Making sure you have clean conditioned air is is important year round - it's equally important to get cold conditionad air in the summertime, but since it is the winter, I'm using that example.

Keeping your conditioned air inside your building shell is important for several reasons. First of all, it ensures the air within your home is clean and filtered (ideally- more on your hvac and combustion appliances in a latter post). You want to be breathing and living in the clean filtered conditioned air and not dirty, unfiltered air leaking in from the attic or the outside. Keeping your conditioned air also increases the efficiency of your heating system, which decreases the amount of energy it takes to heat your home. Increasing your efficiency helps the environment and your wallet by using less energy and electricity every month.

When it comes to the appliance heating your home, even the best HVAC systems do not work to their maximum efficiency- even the best are in the 80-90 percent efficiency region- so no matter what you do, there already will be some inherent inefficiency in your system. But if you have leaky ducts, you can lose up upwards of an additional 40% of that conditioned air out through your ducts and into your attic or the open air. So, by inspecting and sealing your ducts, you can ensure that you are efficiently using as much of your conditioned air as possible.

The duct work in many homes, especially older homes but even homes that have been built within the last 5 years, is often incomplete- many duct connections are not sealed correctly. Worse, they are sealed with duct tape, which isn't actually good for sealing ducts because it will deteriorate quickly, often over just a few months. The first step is to mastic and properly tape all available connections.

If your ducts are not accessible to be masticed and taped, the best solution may be Aeroseal, an Elmers glue like product that blows through your ducts and binds together to seal the gaps. No matter how leaky your system is, Aeroseal will bring your duct efficiency to the 3%-5% range. It is a simple, but relatively time intensive process, but it is well worth doing for the amount of clean air it will keep in your house and the amount of money you will keep in your wallet by increasing the efficiency of your house.

To see more Green Thoughts on Thursday posts, please go to

Full Disclosure: EDGE Energy hired us, as Sum of Change not individuals, to produce several videos for them including the ones in this post. We have not been hired to distribute, recommend, or advertise for EDGE Energy, rather we are using these videos to explain a vital service and we appreciate them letting us do so.

To learn more about the energy audit from Edge and see more of our videos, please go to and see Edge's youtube page

1 comment:

  1. Aeroseal seems like a very clever solution to heat loss. Another heat loss tip is to seal your garage as well as your attic. If you notice the room above your garage is a lot cooler than the other rooms in your house look in the ceiling of the garage for leaks. A little expanding foam can seal them up.