Once you determine that you want a heated garage, you have to select a heater. There are a number of different heaters available. The two recommended heaters for a garage are a forced-air heater and a low-intensity infrared heater. Be sure that you don’t purchase a high-intensity infrared heater because these are dangerous to use in a garage.
The size of the heater you need is going to be determined by a number of variables. You will need to consider the size of the garage, the climate, and the desired working temperature of the garage. The heater is going to be measured in BTUs. BTUs are British Thermal Units and the higher the BTUs the more heat the heater will produce.
Forced Air Heaters
If you decide to purchase a forced-air heater, you should be looking for something no less than 45,000 BTU if you have a 2 car garage. 60,000 BTU is recommended for a 3 car garage. However, the climate in your area will have a lot to do with choosing your heater. Those in areas with very cold winter climates have used forced air heaters up to 80,000 BTU with no problem.
Low-Intensity Infrared Heaters
Low-intensity infrared heaters use a different process to raise the temperature of your garage. A 2 car garage can be adequately heated with a 30,000 BTU unit. A 50,000 BTU unit is recommended for a 3 car garage. Again, areas with an extremely cold climate will probably have to increase these levels for adequate warmth in the winter months.