By Joel Wensley
While duct tape may have many uses, ironically, sealing heating and cooling ducts is not one of them.
As it turns out, the adhesives used on standard plastic duct tape dries out quickly and ceases to hold.
Solution: The real stuff, which is called aluminum foil tape. This is a two-mil aluminum foil duct tape with a paper release liner. It goes on easily and stays on the duct for the duration — even the lifetime of the ductwork in most cases.
Sealing both the supply and return ducts are beneficial for a few reasons. Sealing the supply ducts (the ducts that the air is forced through and then up into your home) is a great idea to keep the air flowing where it was intended to and not through unsealed cracks and seams, which makes some areas hotter or cooler than they should be. A good example of the latter is how cold it tends to be in your basement when you’re running your central air conditioning.
In many cases, ductwork is exposed openly in a crawl space of a home. We definitely don’t want to lose any heating or cooling there. That’s just money down the drain.
For return air ducting, it’s important for the furnace or air conditioning blower to “draw in” just as much air as it pushes out. This is what return air does. It draws the air in to give the blower something to blow. Leaking return ductwork can mean it’s drawing air in from places you may not want it to, such as crawl spaces, musty basements, laundry rooms or even bathrooms.
One other way to save money by sealing your ductwork is to use what’s called mastic adhesive. This is a type of a paste that is made especially for sticking to and sealing up the metal pipes and lines that your air flows through.
Simply use a mastic brush and paint it on over the areas where you feel the air leaking out from. Let it dry, and it’s as easy as that.
You can get both of these products at your local home improvement store, and whichever way you choose to keep the air in, you’ll be saving money and staying more comfortable all season long.
Joel Wensley is a licensed mechanical contractor in the state of Michigan, a member of the Comfort Institute, and is also the president of Mechanical Heating & Cooling in Dearborn Heights.