The obvious, but often overlooked, place for home air leaks

Published by Parisa Ostovari

Updated: November 11th, 2021

As an energy-conscious Des Moines homeowner, you probably read our blog post about how to reduce air leaks in your house. Following the tips outlined there will help your home be more comfortable, keep your HVAC system from working overtime, and keep your heating and cooling costs from increasing. But that’s not all …

An obvious, but typically forgotten, cause for air leaks is duct leakage.

Have you ever wondered why one room in your home isn’t heated or cooled as well as other rooms? Or, does your basement seem much warmer than it should be? These problems could be from a leak (or leaks) in the ductwork. Sound terrible? Don’t worry — it’s fixable. I’ll get to that in a moment, but first, it’s important to understand how the ductwork was designed. 

Design Factor in Leaky Air Ducts

The ductwork in your home allows air to move from the furnace and air conditioning unit to all parts of the house. Depending on your type of house, ductwork can run from the basement to the attic or vice-a-versa. Some homebuilders design the ductwork to run through the attic, with the air coming into the second (or third) floor via ceiling registers. This means if there’s a leak in the duct — that lost air never reaches its final destination and is unfortunately wasted in the basement or attic. In turn, the HVAC system has to work more to reach the desired temperature and you have to pay more in heating and cooling costs.

Preventing Ductwork Leaks

It’s ultimately up to the builders to ensure a quality duct system. Surprisingly, until the past decade, there had been no regulations ensuring ducts were leak-free. In the mid-2000s, building codes began requiring builders to seal ductwork for maximum energy efficiency. In fact, homes built since 2007 must pass an air leakage test.

Air Sealing Your House

If you think your ductwork may have a leak, here’s what to do. You can easily check for leaks any place the duct is exposed by feeling for escaped air. If you locate a leak, you can use mastic tape to seal it. Keep in mind, it’s possible there are more leaks hiding behind the walls, floors or ceilings.

This is why I suggest calling a professional. Sealing your ductwork using a product called Aeroseal® can help improve the comfort in your home and reduce leaks by up to 90%. Sealing your ductwork also provides better air quality because dust, dirt and pollen are not being sucked into the ducts and pushed around your house.