What Size Furnace Do I Need?

Furnaces don't come in a one-fits-all size. Every home has its own heating needs; therefore, the size of the furnace differs among homes. If you're not a professional in these units or have never used one before, it can be hard to figure out your home's ideal size. But there are ways to find an appropriately sized furnace to match your home's heating capacity.

 

Furnace Heating Output

The capacity of a furnace is measured in British thermal units (BTU) per hour. For instance, you can get a furnace with a manufacturer rating of 100,000 BTUs per hour. The outputs of different furnaces vary with a range of 20,000 BTUs. This means you're likely to get furnaces of 60,000 BTUs to 100,000 BTUs for moderate heat output.

 

But you should not only stick to the BTU when shopping for a furnace. Also, consider the efficiency rating. A furnace with a 70% efficiency rating and 60,000 BTUs will deliver 50,000 BTUs heat output. The 10% difference will be the heat lost in the process.

 

Output Per Square Foot

To get the right BTU and efficiency rating, you must know your furnace's heat load depending on your home size. For homes that measure 3,000 square feet, you figure about 40 to 45 BTUs per square foot, so you would get a furnace that can produce 120,000 BTUs to 135,000 BTUs. For homes that are 2,400 square feet and you figure 35 BTUs per square feet, get a furnace that can produce 84,000 BTUs. The calculation of heat output per square foot also depends on whether your climate is cooler or warmer.

 

Other Factors to Consider

Along with your home size per square foot and your area's climate, other factors that determine your ideal furnace's heat output include:

  • Your home

  • Glass doors and window sizes

  • Availability of other heat-generating sources such as fireplaces

  • House layout (open floor plan or small, closed rooms)

  • The house orientation

Get a Professional Calculation

Calculating the size of furnace your home needs is not rocket science, but it can be challenging if you have to factor in so many things. Save yourself from the trouble by working with experts from New River Heating & Air. We help Radford, VA, residents come up with an accurate assessment of their heating needs and the load requirement. Let's work together to ensure you get maximum comfort during the chilly winter months.

HeatingNaomi PluchelFurnace Installation, Heating System