Updated: April 2024

When sizing a furnace for your home, your HVAC professional will calculate the correct measurements in BTUs. Knowing a bit about how many BTUs your home’s heating system needs will help you get an idea of how to size a new one.

What is a BTU anyway?

A BTU is a measure of thermal energy and stands for British Thermal Unit. It’s the amount of energy required to heat one pound of water by one degree on the Fahrenheit scale. For example, burning a four-inch kitchen match to ashes will produce approximately 1 BTU.

How many BTUs do you need to heat your home?

As a rule of thumb, you need between 40 to 45 BTUs to heat one square foot of your home. If your home is 2,000 square feet in size, you need a heating system that generates between 80,000 and 90,000 BTUs. You can use this rule of thumb to get a rough estimate of how much a new heating system will cost. However, it’s important to have a heating professional make the final calculation.

An HVAC professional uses a more complicated system, like the Manual J Load Calculation, to calculate the number of BTUs your new heating system will need. This system factors in how many windows are in your home, your home’s layout, insulation, efficiency, as well as the number of floors you have to heat. All these factors can increase or decrease the number of BTUs you need to keep your home comfortable during the winter.

Why is proper sizing so important?

Buying a home heating system that’s too large will cause it to turn off and on frequently. This cycling is not energy efficient. It also causes more wear and tears on your equipment, increasing repair costs. If you purchase a system that’s too small, it will run continuously, driving up energy costs.

If you need to get an accurate BTU estimate for your new furnace, contact Pipe Works Services today. We service Chatham, Morristown, Basking Ridge, Union, and the surrounding areas!

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