If your garage is not heated but you would like a way to raise its temperature, installing a propane heater is one viable option. Propane heaters are widely available, and there are many units capable of heating a garage that's 600 square feet or less. However, before you decide to install the propane heater, there are some factors to consider.
Pro: Propane is an efficient heating fuel.
The alternative in a small garage space is often an electric heater. These are far more expensive to run than a propane heater. Propane is also a pretty eco-friendly gas. It burns cleanly, does not result in a lot of smoke or exhaust, and you can run your heater for many days even on a small tank of the gas.
Con: You will need to get a propane tank filled.
Propane does not come into your home via underground lines like natural gas does. You will either need to buy a large propane tank and have it mounted in your yard, or you will have to keep hooking small, grill-size tanks up to your heater. Since having a large tank installed is pretty expensive, many people choose to use grill tanks in their garages. This is pretty affordable, but you will need to remember to have the tanks refilled or replaced quite often.
Pro: Installing this heat system is easy.
When you're just heating a garage, there are no ducts to worry about. You can just buy a heater with a single fan to blow the heated air out through your garage space. This means the heater will only take your HVAC contractor a few hours to install, at most. You won't need to make any extensive renovations or pay an expensive installation fee. Your heat can be up and running the same day!
Con: Propane heaters do have an open flame.
Since there will be an open flame associated with your propane heater, you will need to be very careful around it. You won't want to spray any finish or other material that is combustible in your garage. If you have kids, you won't want to leave them unattended in the garage with the heat on.
As long as you're willing to go through some safety protocols and exchange tanks, propane heating is a very smart choice for your garage. Talk to an HVAC contractor in your area to see what make and model they recommend for your space.