According to the Department of Energy, the typical duct system in America has an average leakage rate of 25%. This means ¼ of the air moving through your duct system is either leaking outside or being sucked into your ducts. Over my years of doing energy audits, I have seen leakage rates as low as 3% to as much as 60%. What a waste!
Leaks on the return side of a system means hot, humid, dirty air from your attic, crawl space or basement is being sucked into your system to be redistributed throughout your house. Leaks on the supply side means the air you are paying to condition is being lost outside, wasting money. Both of these situations decrease the performance of your HVAC equipment, decrease the indoor air quality in your home, and cost you extra money on your utility bill.
What’s the cure? NOT TAPE! Many HVAC technicians tape the heck out of the duct connections hoping it will minimize leakage. The problem is that the adhesives WILL FAIL! Even the higher end foil faced HVAC tapes will eventually fail. By the way, just because it’s called DUCT TAPE doesn’t mean you should EVER use it to seal your ducts or HVAC equipment.
So what’s the real cure? DUCT MASTIC! Duct mastic comes in a tub and looks a little like drywall mud. It is waterproof and somewhat flexible. When applied properly (about the thickness of a nickel) it basically forms a semi-flexible cast over the connections. Mastic (again if applied properly) should last many years.
If your ducts leak significantly, you would be amazed at the difference in the air flow once they are properly sealed. I have sealed many a duct system and I’m never surprised by the comments made by the home owners. So do yourself (and your home) a favor and have your ducts checked for leakage. You’ll thank me when you pull up the blanket in the middle of the night because it’s a little chillier in your bedroom than it used to be.
If you have any other questions on this subject, please leave a comment below or you can email me at JonL@theNRGguy.com or contact me through Facebook or my Website. Until next time…..Don’t throw money at your problems, throw knowledge, it’s a lot cheaper.