HVAC Systems and Roofs: How They InteractThere are a number of factors that affect how your HVAC system works, many of which you probably don’t even think about. One of those factors is your roof. The materials it’s made of and how it’s installed can raise or lower your energy efficiency.

Here’s how, and what you can do about it.

Heat Absorption and Reflection

If your roof is covered with dark, asphalt shingles, they’re absorbing heat. In the summer, they can reach over 150 degrees in direct sunlight. That heat then heats up your attic, and from there, spreads to the rest of the house, forcing your HVAC system to work harder to keep the space cool.

The good news is, many modern asphalt shingles are coated with a special material that allows them to reflect the sun’s heat. If you have an older roof, replacing it with newer shingles to keep out the heat might be a good investment. You might also consider tiles made of slate or clay, which can be obtained in a variety of different colors. By selecting a lighter color, you can help your roof reflect heat instead of absorbing it, keeping your house cool.


If you do decide to install a new roof in your home, be sure it’s properly insulated. By putting a layer of insulation underneath the tiles or shingles, it creates a barrier to stop the heat from getting into your home. Talk to your roofing contractor about proper insulation and what that option will cost. Keep in mind that it’s an investment. While it might cost extra, you’ll make up the money in lowered energy bills.

If your ductwork runs through the attic, consider insulating that too. When the attic gets hot, the ducts do too, and the cold air running through them is less cool by the time it reaches your home. By insulating your ductwork, you keep your HVAC system working at peak efficiency.

To learn more about how your roof affects your HVAC system, contact us at Mowery Heating, Cooling and Plumbing. Indianapolis trusts us for all their heating and cooling needs.

Our goal is to help educate our customers in Brownsburg, Indiana and surrounding areas about energy and home comfort issues (specific to HVAC systems).