You’ve decided to make the switch to a propane heater, which is a great choice. A propane heater is cheaper than gas or a wood-burning fireplace, and burns clean. It’s non-toxic, and doesn’t harm the environment. It is safer to have in your home than natural gas because of its high burning point (it has to be much hotter to light propane than gas, making for fewer accidents).

So now where do you go? Well, you need to determine how many BTUs you need for your propane heater. BTU stands for British Thermal Unit, and is a measure of energy unit equal to 1055 joules. According to Wikipedia, “A BTU is defined as the amount of heat required to raise the temperature of 1 pound (0.454 kg) of liquid water by 1 °F (0.56 °C) at a constant pressure of one atmosphere.”

There are two factors in defining how many BTUs you need. The first is the size of your home, and the second is the climate zone you live in. Obviously it takes more energy to heat a larger home than a smaller one, and a home in a cooler area of the country requires more energy to heat than one in a warmer region.

The formula is straight-forward: Start with the square footage of your home. Next, refer to this reference guide and match up your square footage and climate zone.

For instance, say you have a 1500 square foot home in North Dakota. North Dakota is a Zone 5 climate. That’s 50 to 55 BTUs per square foot.

1500 (for square footage) x 50 = 75,000 BTUs to heat your home.

If you are looking for a smaller propane heater to heat a separate area of your home, then the same principles apply. Simply plug in the square footage of the desired room or rooms to be heated.