Choosing The Right Furnace for Your Needs

Choosing The Right Furnace for Your Needs

In choosing the right furnace that gets the job done, of course, you'd want to select the one that not only keeps your home warm but also does not burn a hole in your pocket. 

The common myth that bigger furnaces are always better must be debunked. Generally, bigger heaters are perfect for large areas, but what good does that do when the space you're trying to warm up is modest in size? 

If you want to know about the criteria to look out for in choosing the right furnace, read until the end of this article.


Why does the correct furnace size matter?

Before we go through the guide, we believe it is best to discuss why choosing the right size for the furnace matters. A furnace that fits perfectly into your house will warm it gradually. It will require fewer repairs (lowering your overall maintenance cost), may last longer, and is more energy-efficient than an oversized or undersized furnace. It will also heat your house evenly, so no area is hotter or colder than the rest of the house. 


Some numbers

In choosing the proper furnace size, you need to crunch a few numbers. First, you have to consider the size of the room you're trying to heat up. Get the square footage. If you already have that, then good. 

Next, you have to determine the BTU requirement of your home per square foot, depending on which climate zone you belong to. BTU is the acronym for British Thermal Unit, the designated unit used to measure heat energy in energy sources or fuels. It is the amount of heat required to raise the temperature of 1 pound of water in liquid form by 1 degree Fahrenheit at the temperature that water has its greatest density (approximately 39 degrees Fahrenheit). For the climate zones, refer to the guide below:


  • Zone 1: 30 to 35 BTUs (such as Southern regions in the United States (such as Houston, Miami, and New Orleans) 
  • Zone 2: 35 to 40 BTUs (such as Tennessee, North Carolina, parts of Oklahoma, and coastal California)
  • Zone 3: 40 to 45 BTUs (such as Virginia, Kentucky, Kansas, and Delaware)
  • Zone 4: 45 to 50 BTUs (such as New York, Chicago, and Boston)
  • Zone 5: 50 to 60 BTUs (most of the northernmost states)



The following examples will help you calculate the BTU Output your furnace must have: 

  1. If you live in a well-insulated house that is 1,200 square feet at zone one, you must multiply 1,200 by 30, which results in 36,000. This means that you need a furnace with a 36,000 BTU output. 
  2. A poorly insulated house with 1,000 square feet is located in zone four. Multiply 1,000 by 50 to get a product of 75,000. This means you need a furnace with a 75,000 BTU output.

Another way of calculating the BTU output is by multiplying the furnace's input with its efficiency. For example, a furnace that has a 75,000 BTU input with a 90% efficiency will have an output of 67,500 BTU.


Other factors affecting furnace selection


Other factors that you may consider in choosing the correct furnace for your home may include the following:

  • Family Size
  • Windows and Number of Floors
  • Sun Exposure and Roof Color (darker roofs absorb more heat)
  • Ceiling Height and Ceiling Fans
  • House Shape
  • Preferred Temperature



When searching for a furnace to heat your home, the size is important. A furnace that is too large or too small can not only result in uneven heating in your home but may also increase your energy consumption. Thus, it will cost you more money. 

Do you have concerns with your HVAC system? Please feel free to contact so that their team can help you find solutions to your problems.

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