For this step you ll need to determine how well the garage is insulated to get the last variable for the equation.
How many btu to heat uninsulated garage.
These are very effective at providing heat to large spaces they contain a blower fan connected to a heat exchanger that allows for heat to be provided directly at a desired location.
Procom tank top propane heater double burner 30 000 btu model pctt30 propane heaters are a good low cost solution and can put out a lot of heat.
Newair s portable electric garage heater has a heating capacity of more than 19 000 btus enough for most 2 car garages in a cool climate.
This likely isn t a problem in a garage with no insulation but every garage is different.
If desired the unit heater may be connected to a thermostat for ideal.
If you want to heat a garage pole barn or a workshop or any space like that the best way to do this is with one or more unit heaters.
Insulation quality x total cubic feet x desired heat rise 1 6 btu required.
You need a heater with at least a 21 780 btu output.
For example if your uninsulated garage is 484 square feet your formula is 484 200 x 9 000 or 21 780.
3 position the garage heater in the desired location.
Many other heating options portable electric baseboard heaters can provide an energy efficient source of warmth for smaller garages with a convenient low profile.