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What’s the Right Size Furnace for My Home?

What’s the Right Size Furnace for My Home?

What’s the Right Size Furnace for My Home?

Have you ever moved into a new home and felt your furnace wasn't heating your new space evenly? If this is the case, the furnace is probably not the right size for your home. A furnace will heat rooms poorly if the unit is too small or too big for the space. When it comes time for a furnace replacement, you may be wondering what size furnace you should be investigating. At Restano Heating, Cooling and Plumbing, we've put together some tips on how you can determine the right size furnace for your home!

The Importance of Furnace Size

The size of your furnace is crucial. If you end up with a furnace that is too small for your home, you will have uneven heating and high energy bills. The furnace will also have a shorter lifespan because it is working harder to heat a larger space.


If your furnace is too big, it can cause parts of your home to be sweltering hot or unevenly heated and lead to a failing heat exchanger. The furnace will also cycle on and off too frequently, causing your furnace to wear out faster.

Consider Your climate Zone

Another essential aspect when choosing a furnace is the climate. If you live in a colder winter climate, your furnace will be used more than if you live in a mild climate. Pittsburgh homeowners live in a cold, frigid climate zone. Your home will require a more powerful furnace than someone in California in a mixed dry or hot, dry climate zone. So you will be looking for a furnace that is more heavy-duty.

Find or Calculate the Square Footage of Your Home

Gas furnaces can be differentiated by their British Thermal Unit (BTU) capabilities. One BTU represents the amount of energy that is required to heat one pound of water by one degree Fahrenheit, so to determine the correct BTU for your home heating, you will need to make some calculations.


The square footage of your home should be on the paperwork you received when you bought your house, or you should be able to reach out and ask your realtor. If you can’t determine the square footage from these options, then you can calculate the square footage yourself.

Begin by measuring the length and width of each room in your home. Multiply the length and width of each room together. This will give you the square footage of each room. Once you’ve determined the square footage of each room, add them all together to get the square footage of your entire house. It’s important to note that most furnace size charts assume that your ceilings are eight feet high. IF they are higher or lower than eight feet, be sure to adjust your measurements. When taking measurements, keep in mind that you do not need to measure rooms that do not have ductwork or that you don’t plan on heating, such as a sunroom.

Many of the furnace size charts follow similar guidelines such as:

  • 1,200-square-foot home will require between 35,000 and 75,000 BTUs
  • 1,800-square-foot home will require between 45,000 to 90,000 BTUs
  • 2,100-square-foot home will require between 65,000 to 125,000 BTUs

There are a variety of furnace size charts available, and each of them gives you a comparison between home square footage and the BTUs required to heat the home.

Furnace Installation Services, Pittsburgh

As your local heating and cooling company, Restano Heating, Cooling, and Plumbing can help you find the right furnace for your home when it comes time for a replacement. Our expert team can install, service, and replace your furnace system to ensure you stay warm this winter season. Restano Heating, Cooling & Plumbing offers a free estimate for furnace installation, assisting homeowners in their furnace size calculation. When you search for "furnace installation near me," be sure to choose Restano for unbeatable customer service and competitive pricing.

Recently Rich & Mimi, Restano Heating, Cooling & Plumbing customers experienced the process of a furnace installation to replace a 45-year-old furnace. Read about their experience! "Bill and Jeremy completed our furnace and air conditioner replacement (we had a 45-year-old furnace) in such an efficient manner. They were so diligent, polite, and thorough. Brian, who came out to assess and gave us a quote, was also great - so surprises and scheduled us quickly. Excellent overall experience - we were unnecessarily dreading this - they just got to work, cleaned up everything, including old/unused equipment left behind by previous workers. The cost was also reasonable (we researched 4 companies)."


Call Restano Heating, Cooling & Plumbing, your trusted Pittsburgh heating and cooling company, for assistance with a furnace replacement. Contact us today to learn more!