What You Need to Know About Installing a Furnace in Your Attic

Updated: Oct. 06, 2023

If you're looking to increase livable space in your home, consider moving the furnace into the attic. This installation is more common than you think.

installing furnace in an atticperrygerenday/getty images

There is a common misconception that it’s impossible to have a furnace — a major component to an HVAC system — installed in the attic due to tight space and minimal access. This is not the case. As long as the attic is fully insulated, installing a furnace in the attic as part of an HVAC system makes a lot of sense for many homeowners.

Installing a Furnace in Your Attic

Typically a furnace is installed in the basement, a hall closet or the garage. But what if you don’t have a basement, garage or suitable closet?

“Attic furnace installation has been done for decades,” says Chris Roth, a licensed HVAC contractor and the owner/CEO of National Technical Institute in Las Vegas. “Space elsewhere in the home may not always be an option. This has led to the rise of people wanting to put their furnace in their attic.”

Many states allow furnaces to be installed in attics, as long as strict national standards and state codes are followed.

Benefits of Putting Your Furnace in the Attic

It can be easy to install

Most homes have an attic, and many modern furnaces can be installed vertically or horizontally, depending on the home. “More manufacturers are designing furnaces that can be installed in a variety of ways, like horizontally, which make them especially attractive for attic installations,” Roth says. A spacious attic can also make installation easy, whether on the attic floor or suspended from the rafters.

Using your attic clears storage space

If you have your furnace in the garage, the basement or a closet, you lose that space for storage. Attics are often left empty, making them a good choice for the furnace and freeing up storage space elsewhere.

Installation may be slightly cheaper

Installing a furnace in the attic can actually save you money because you can vent it directly through the roof, says Roth. “Duct work installation will not be as tedious or involved, which can make the cost lower,” he says.

Less risk of damage caused by flooding

A furnace housed well above ground is a lot less likely to suffer flood damage. Whether from heavy rain, a busted sump pump or ice and snow melt, flooding can severely damage, destroy or create a hazardous situation with a furnace installed in the basement or at ground level. You may have no choice but to replace a furnace damaged by flood water.

Drawbacks of Putting Your Furnace in the Attic

Problems may go unnoticed

One of the most common signs of a failing furnace are unusual noises, like a squeaky fan motor. “If the furnace is up in the attic, you may not hear the sound,” Roth says. “This can lead to not knowing there is an issue with the furnace until it is broken completely down.”

Increased chance of duct work issues

In the summer months, attics can get extremely hot. This can cause furnace duct work to develop pinhole leaks and small tears. When running the air conditioning, if you notice your cooling power has diminished, it could be a sign of leaky duct work.

Naturally lower efficiency

Remember your junior high science: Warm air rises, cool air sinks. A furnace installed in the attic forces warm air to the bottom floor instead of letting it rise naturally, as it will from the basement. That may lead to higher energy bills and less efficiency. So Roth says if you go with an attic installation, choose a high-efficiency model.

More holes into your ceiling

Because warm air rises, an attic furnace requires more duct openings in ceilings to push the warm air down and around and create a comfortable temperature in the home.

When Can I Install a Furnace in My Attic?

You can install a furnace in the attic at any time — during new construction or a remodel. We recommend hiring a licensed professional to do the installation to make sure all safety rules and local codes are followed.