What Size Furnace is Right for My Home?

The wrong sized furnace can cause a long list of problems for your home during winter. If it’s too small, it will run harder than it needs to and still won’t heat your home properly. If it’s too large, it will turn on and off too often, a problem known as short-cycling that decreases your furnace’s lifespan, causes moisture build-up, and results in costly heating system repairs.

Measuring Heating Capacity

Finding the right sized furnace depends on its BTU’s (British Thermal Units, a measurement of how much heat a furnace radiates) and efficiency. The equation looks like this:

BTU x Efficiency = Total Heat

Therefore:  A 1,000 BTU Furnace that is 80% Efficient = A Furnace Radiating 800 BTU’s of heat

That’s the easy part. Determining how many BTU’s your home needs to be comfortably heated is trickier. Variables like the amount of windows, insulation performance, whether you have duct sealing, and so on, all affect the size furnace your home requires.

Calculating Size

If you’re replacing your furnace, the easiest way to determine the size of your new unit to look at your old one. If you are switching to a new type, however, sizing varies according to things like the model’s energy efficiency.

One way to help you pick a new model is with a J Load Calculation Manual, a helpful tool available from the Air Conditioning Contractors of America (ACCA). The manual helps you calculate all your home’s unique variables to determine the right size furnace. EnergyStar also offers a free online calculation tool to help you determine your needs.

Better still, a professional heating system repair company can come into your home and provide an evaluation and estimate for you. The friendly, professional HVAC contractors at Precision Air and Heating can help you make your selection, as well assist with heating maintenance plans to keep your furnace in top shape for years to come. For all your  duct cleaning and heating system repair needs, call Precision Air and Heating at 602-fix-my-ac or schedule an appointment online.


Precision Air & Plumbing June 8, 2017


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