What Size Propane Heater Do I Need?

Do you know how big a propane heater needs to be to heat a certain size room, garage or workshop space? The answer is fairly simple and is explained here.

The first thing you need to know about is the rating of a heater, which will be stamped in the information label somewhere. The rating is depicted as a number followed by the letters BTU, which stand for British Thermal Unit.

Now you might jump to the conclusion that this is an American heater, so what have British measurements got to do with anything? Well, this is an old measure that has been adopted pretty much all around the world, so might as well keep it since its pretty universal.

How is BTU Defined?

One BTU is the amount of heat needed to heat one pound of water by 1 degree Fahrenheit. OK, you cam breathe a sigh of relief, cause at least there's no metric stuff in there to confuse things! We all know what a pound of water is and what degrees Fahrenheit are, right?

There is a simple way to work out the amount of BTUs you'll need to heat a space, measured in cubic feet. You first need to measure the room you need to heat and write down the floor's width, length and the height of the ceiling.

Working Out How Many BTUs You Need

Once you know the dimensions of the room you want to heat, you need to do a little simple arithmetic. Multiply these three number together (W x L x H) and that will give you its volume in cubic feet.

By way of an example, if your room is 10ft wide by 20ft long and 8ft high, then the calculation will look like this:

10 x 20 x 8 = 1,600 cubic feet

Then multiply the result by between 2 and 4 depending on how well the room is insulated. If you're not sure, err on the low side and multiply by 4. This will give you a figure of:

6,400 BTU per hour

All you then need to do is check the BTU rating on a few propane heaters that you have in mind and choose the one that comes closest. That's about all you need to do to get a heater that will definitely be capable of heating up your space efficiently and with minimal cost, since propane is still a relatively cheap fuel compared to other forms of energy.

Simple? Sure it is!