Attic Furnaces: Why would you put a furnace in your attic?

Attic furnaces are something more homeowners have been considering in both residential and commercial buildings. Typically, residential and commercial buildings have furnaces installed in their basements but moving your furnace to the attic or having a furnace installed in your attic can provide greater convenience and safety.

Attic furnaces can at times be more challenging to service, but this is mainly because most attics are smaller than basements. Outside of negotiating the tight quarters for furnace maintenance, there are many benefits to an attic furnace, one of them being convenience. For many the advantages of putting a furnace in the attic outweigh the few occasions where furnace maintenance may be necessary.

Furnace in attic pros and cons


Installation can be simple: A lot of hvac manufacturers are designing a wider variety of furnaces to fit all types of homes and living spaces. Attic furnaces were a natural and necessary innovation because not everyone has a basement, garage or functional closet.

For homes and living spaces with attics modern furnace designs allow you to install them either vertically or horizontally. Horizontal attic furnaces are increasing in popularity because they can be hung on a wall or rafters and are easy to install, especially if you have a decent amount of space.

More affordable installation: An attic furnace can be ventilated outside much more easily because of the location. Venting the furnace here requires less ductwork than in other areas of the home assuming you do not have a concrete or slab roof. This enables many to save on the cost of furnace installation due to less ductwork being necessary.

Choose an Electric or Gas Furnace: Installing or moving a furnace to your attic should only be done if you have measures to detect any issues and proper ventilation in the space. A gas furnace in your attic is just as easy to install as an electric one, just ensure your alarm systems work correctly so you can quickly detect any leaks. When your furnace is in the attic it is out of sight, so small issues arising will be less obvious.

Saves space: Attics usually are left empty with no real utilization of the space. Sometimes this is because the space is too small to make functional, but it could be just big enough for an attic furnace. This could help free up space in a basement or garage if that is where your furnace is currently located.

Less risk from flooding:

If your furnace is currently in your basement and your basement floods, there’s a chance it will incur some damage. A furnace that is damaged by water may need to be replaced for your safety. Regardless of the cause of the flooding (rain/snow, sump pump malfunction, natural disaster), with a furnace at ground level or below it creates a hazardous situation.

An attic furnace or any furnace well above your ground level is less susceptible to flooding.


Can Lower Efficiency: One thing to consider with an attic furnace is that heat rises. When your furnace is in your attic it must push the warm/hot air downwards throughout the house to bottom floors. With a furnace in the basement the warm/hot air is allowed to naturally rise, and this dynamic is more energy efficient.

Out of sight out of mind: When a furnace or other hvac system aren’t functioning correctly a lot of times the warning signs are apparent. If you hear unusual and/or squeaking sounds coming from your furnace this could be a sign your furnace is currently or soon will begin failing. With an attic furnace you may not be able to hear the rather obvious warning signs there’s an issue. Without a few furnace maintenance checks throughout the year you may not recognize you have a problem until your system has failed.

Potential ductwork issues: In the summertime your attic is one of the hottest places in your home. The heat from here can cause furnace ductwork to develop very tiny tears/holes. Because you aren’t running your heat in the summer this potential ductwork issue is more noticeable when running your air conditioning. If you feel that the cooling power has decreased, it could be a result of tiny holes in your ductwork caused by hot temperatures.

How much does an attic furnace cost?

The cost of an attic furnace is going to vary based on the type of furnace that makes the most sense for your space. Whether you choose horizontal or vertical, gas or electric, every home will have different requirements that make having a furnace in your attic both efficient and functional.

The average cost of a furnace can range from $1,795 – $6,290 and the price will vary based on a number of variables. Check out our furnace cost guide to read about the ones that matter the most.

A good option if you are considering a furnace in your attic is to get one with high efficiency. A high efficiency furnace in your attic can help balance any decreases observed by trying to move heat against its natural direction throughout the house. High efficiency furnaces require less energy to run than traditional furnaces but can cost up to twice as much.

Learn more about high efficiency furnaces here.

Attic furnace requirements

Attic furnace installation must comply with either local mechanical code or International mechanical code (IMC). Below are some attic furnace requirements that align with most codes based on regions in the United States.

An attic furnace passageway minimum dimensions are: 30 inches high, 22 inches wide and 20 feet max length. The dimensions must be large enough to remove the largest hvac system or furnace appliance installed up there.

How to install a furnace in your attic?

The process for installing a new furnace in your attic or moving a furnace to your attic depend on a number of variables. Your home layout, the size of your attic as well as temperatures in hot and cold seasons locally should impact how you approach this.

For assistance with your attic furnace installation or help answering any questions you have related to the installation process please contact us.

How Much Does HVAC Replacement Cost?

Average Cost: $3,250 – $12,586

Like your home and needs, your HVAC project cost will be unique. Use the calculator to better estimate your investment.

*Estimate is based on current data and does not represent a guaranteed price. For accurate pricing contact a local HVAC dealer.

$5,000 – $6,000

Estimated Total

The average cost for a new HVAC system is $3,250 to $12,550, which includes equipment and labor fees for the installation of a central AC unit and gas furnace. The chosen HVAC brand, necessary ductwork repair, and your location will influence the project cost.