Where Should A Furnace Be Located In A House?

Are you figuring out where to place your newly purchased or rented furnace inside your home? Finding the perfect spot for such a large system can be confusing. Therefore, we researched and have a few ideas to share below!

The location of a furnace in a house should be in either a confined or unconfined space with adequate space and ventilation. Similarly, the furnace size and type determine the best location.

These are the common areas where you can place your furnace:

  • Attic
  • Crawlspace
  • Garage
  • Basement or utility room
  • Large laundry room

Keep on reading to find out more about the types of furnaces and the characteristics of each location for each type. We will also answer other related questions which you may have in your mind. Let's begin!

A home high energy efficient furnace in a basement, Where Should A Furnace Be Located In A House?

Things To Consider When Placing A Furnace

A home high energy efficient furnace in a basement

There are basic factors you need to consider when choosing your furnace location:

Furnace Type

There is a wide selection of furnaces. Each type has a unique speed, valve settings, and installation requirements.

Gas-Fired Furnace

The most popular furnace needs a natural gas pipeline. Thus, its location must be near the line. Also, people usually install it along with a central AC unit.

Oil-Fired Furnace

You must allot a bigger space if you want a pressure burner or oil furnace. It should cater to the 275-gallon oil tank reserve.

Propane Furnace

This is an alternative if your locality has a low oil or gas supply. Changing the propane tank frequently, its location must be readily accessible.

Electric Furnace

The best choice is an electric furnace if there is no main gas line nearby. Its sizes are usually compact. Without the need for vents, their installation and replacement are straightforward.


The bigger the furnace, the more space you need to have for its clearance and accessibility during maintenance.

Ventilation And Airflow

To function correctly, a gas furnace needs a continuous combustion air source for gas-fired. Thus, the proper vent system will prevent air leaks. Otherwise, the air source will be from inside your home.

A louvered door is mounted for proper air circulation when the adjacent area is well-ventilated. But for a confined space, a fully sealed solid door is better.

Door Open Vs. Door Closed

Leave the door open to maintain even heat distribution within the furnace closet. In contrast, keep the door closed if you have toddlers and pets. This will also help in reducing potential gas spillage.

Energy Intake

Check the heating system label's Annual Fuel Utilization Efficiency (AFUE) rating. Unlike the SEER rating for AC units, the AFUE rating measures the energy efficiency of a heating system like a furnace.

The higher the percentage, the higher the initial cost. Nonetheless, the high efficiency will help you gain bigger savings in the long run.

The Department of Energy requires a good AFUE of at least 80% for gas furnaces. Advanced furnaces have high efficiency ranging from 90 to 90.8% AFUE. Electric furnaces have the highest ratings (95 to 100% AFUE).

Heat Generation

Although people interchange thermal efficiency with AFUE, these ratings are different. Thermal efficiency rating measures the amount of heat generation per amount of work.

Common Locations For Furnaces

A home high efficiency furnace with a residential gas water heater & humidifier.

Attics and crawlspaces are confined spaces, whereas garages, basements, laundry, and utility rooms are unconfined spaces.


The attic is an isolated part of the house you can maximize for your gas furnace.

If you do not want to be disturbed by the noise of a furnace, choose an unused attic to fit in the furnace and its drainage pan system. Support beams are strong surfaces to situate your duct.


Placing your furnace horizontally in a crawlspace is ideal for an electric furnace since it is not combustible. As long as you put up fire-resistant materials on the flooring over the unit, other types will still be safe in the crawlspace.


A garage is an option if you do not have another vacant area in your house. Elevating a furnace in a garage requires an 18-inch platform.

Basement Or Utility Room

This room offers the easiest access. Lift the furnace with a 4-inch gap from the floor and put a drainage pan.

A furnace in the middle of the basement and HVAC equipment like a water heater or softener is a typical set-up for a more organized utility room.

Large Laundry Room

If you opt to put your furnace in your laundry area, do not block airflow with your laundry or clothesline.

Common Furnace Problems

Technician servicing heating boiler

Owning or renting a furnace comes with responsibility and challenges as a homeowner. Here are the possible problems you will encounter or issues you want to prevent.

Intake Backflow

The combustion gas backflow allows carbon dioxide and carbon monoxide to diffuse inside your home. A high concentration of byproduct spillages is a health hazard.

Following the US EPA, nine ppm and 35 ppm are the air quality standards for carbon monoxide per 1-hour and 8-hour periods, respectively.

Measure the carbon monoxide levels within your house using a portable carbon monoxide tester with audio-visual alarms between 35 ppm and 200 ppm. It comes with a carrying pouch and batteries.

Check out this carbon monoxide tester on Amazon. 

Moreover, the best precaution is to ensure that there is a backdraft damper or valve during ductwork. This functions as a guard against backflow. The butterfly valve will quickly close to stop horrid odors and particles from entering the duct.

Check out this backdraft damper on Amazon.

Uneven Temperature

Some areas are cooler than others. This is a usual sign of inadequate insulation.

Hence, apart from the insulation within your ceiling and walls, you can install a crystal-clear window film inside your house. This will increase the energy efficiency of your furnace.

Check out this window insulator kit on Amazon.

Likewise, leaks within your doors, windows, and other openings are also sources of inconsistent temperature.

Whether indoor or outdoor, this waterproof sealant protects your window against water, air, and moisture problems. Similarly, it resists mold and mildew.

See this white silicone sealant on Amazon.

Poor Air Quality

Another problem you will encounter is poor airflow due to a dirty filter. The system is forced to work harder to keep you warm. Hence, the quality of air suffers.

For this reason, you need to change the furnace air filter every three months. By doing this, you will get rid of trapped and unwanted particles such as lint, mold, and pollen.

Check out this furnace air filter on Amazon.

Does A Furnace Have To Be In The Center Of The House?

A home laundry room with a dryer, washer, a high efficiency furnace with a residential gas water heater & an humidifier.

As an HVAC technician shared in a forum, proper ductwork is key to balanced heat distribution. Ductwork includes heat exchangers, valves, steam, and hot water pipes.

Thus, your furnace doesn't have to be in the center. Placing your furnace in the attic compared to the basement has no significant difference unless your furnace and other important heating system parts are not properly installed and gauged.

Can You Install A Furnace Yourself?

Due to the technical labor involved in furnace installation, it isn't easy to do it yourself. We recommend seeking competent service providers for this.

Despite that, knowing the overview of the procedure will help you notice the discrepancies.

  • Measure load calculation of the home.
  • Perform ductwork with proper sizing.
  • Install gas line and electrical wiring.
  • Create a PVC drain system or flue liner.
  • Calibrate the airflow compatibility of the furnace and air conditioner.

How Much Does It Cost To Install A Furnace?

The average cost of complete furnace installation in the US ranges from $3,850 to $7,325. This depends on the size, location, and type of furnace.

The gas furnace is the most expensive, while the electric furnace is the most affordable. The installation cost includes the furnace, repair, wall changes, ductwork, ventilation, permits, and labor fees.

Changing your furnace location is possible. However, it will be complicated and costly.

Thus, if you have concerns regarding the current location, you may ask a reputable HVAC company to assess the situation and the need for transfer.

What Should You Not Put In A Furnace Room?

As a rule of thumb, avoid storing anything inside your furnace room. Avoid flammable items like paint, cat litter, and cleaning products.

However, when you have limited space and storing non-flammable items is unavoidable, put some distance. Remember the minimum 30-inch clearance around your furnace.

It eliminates serious accidents and malfunctioning.

Safety Tips For Using A Furnace

Follow these tips to ensure the safety and proper functioning of your furnace:

  • Install ample lighting and secure a flashlight for easy maintenance.
  • Clean the dust and debris regularly. It is a common breeding ground for insects.
  • Conduct regular maintenance and inspection to assess the need for repair or tune-up.
  • Dispose of the old filters properly because it is a fire hazard.
  • Ready fire extinguisher, first aid kit, and emergency contact number.
  • When toxic gases are inhaled, they cause breathing difficulty, poisoning, and even death. Consult your doctor or nearest poison center immediately.

A home high energy efficient furnace in a basement

To Wrap It Up

With the freezing temperatures, furnaces are typical heating systems in American homes. Thus, placing your furnace in a location compatible with several factors mentioned is essential.

Even warm air distribution boils down to proper installation and maintenance.

Thanks for reading! If you enjoyed this post, visit these articles about other HVAC systems:

Furnace Won't Reach Set Temperature - What To Do?

Hot Water Heater Only Lukewarm - What To Do?

How To Hide Kitchen Vent Pipe?

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