Does Furnace Have to Be in Center of House?

Furnaces should not be placed in an unheated area such as an attached garage or closet, nor should they be located in corners where airflow would be restricted.

The reason given in the above statement is that “airflow would be restricted,” which could lead to poor circulation of air through the house. However, there are no specifications regarding how far from a corner it can be. I found at least one site where the furnace was placed within 3 feet (1 meter) of a corner:

The furnace should be centrally located in the house for maximum efficiency.

It should not be placed near a corner or wall but instead should have at least 30 inches of clearance on all sides.

Are you wondering what determines whether there is enough space to avoid airflow restriction around an object that gets hot (such as the furnace)? Is it assumed that hot air rises? Also, could you get away with placing the furnace closer than 1 meter from a corner if there were no walls within 10 feet (3 meters)? There are currently six windows and four doors where you want to place the furnace and an exterior wall; does this affect anything? Are there any other essential factors besides “at least 30” inches?

To answer these and other questions about furnaces and their location in houses, we researched the Internet. Most of the information we found was along these lines:

“To avoid restricted airflow, you need at least 3 feet (1 meter) around any heating appliance.”

“If there is no wall within 10 feet (3 meters), then it should be OK to place the furnace closer than 1 meter from a corner.”

“The heat rising from objects that get hot can make people feel hot even if they are not near them; thus, do not place heating appliances near walls or corners.”

This website gave the most specific advice I found: “For proper ventilation and efficient performance of the heating system, the furnace needs to be located in the center of the house with a clear space around it. There should be at least 10 feet (3 meters) on two sides and 4 feet (1.2 meters) on each other side, as well as above it.”

Other sites had more general advice: “Make sure there is plenty of room all around your new gas-fired furnace for both the service technician and the fumes from combustion.” “Situate your gas heating appliance centrally in the room. Allow a clearance of at least 15 inches on all sides, away from walls and furniture […] Furnaces located too close to a wall will not draw properly.”

Most experts recommend a minimum installed distance between furnaces and interior walls or corners of 3 meters or more, 10 feet being a typical minimum distance.