going to want to heat it when the weather turns cold, and the best way to do it is with a garage heater. Garage heaters come in a variety of shapes and sizes. What you use your... car and some are 4. It's best to get a measuring tape and measure the garage area so you know how much coverage you need. The average garage heater warms from 150-500 sq. ft.... of space. If your garage is bigger than 500 sq. ft. you might need to invest in a couple of different options. Together 2 electric garage heaters can warm up to 1,000 sq. ft. You're...