Join Date: Nov 2009
Location: Downers Grove, Illinois
Up until last year I used a 220v Fahrenheat 5,000 watt (17,000 btu) electric heater for my 20X22' detached garage/shop (440 sq ft). It worked fine but really made the electric meter spin when it was in use. The nice thing with electric is it's 100% efficient. I have R-11 in the walls and R-19 in the ceiling which, while not super, isn't bad. Last November I hung a 45,000 btu Big Maxx and as expected it heats the garage twice as fast with less cost per therm. I am really happy with it and glad I made the conversion to NG.
There are a couple things you need to consider before buying any heater: 1) how cold does it get in your region, 2) how often are you working in the garage and how warm is "warm enough", and finally 3) how well is the garage insulated?
Regarding the last question, a heater in a poorly insulated garage is just throwing money out the window. Case in point. A buddy of mine heats his garage with a LPG torpedo heater rated for 150,000 btu. His garage is the same size as mine but he only insulated the wall, not the ceiling. He also never covered the walls after he hung the fiberglass batting. When he fires up his torpedo it warms the place up alright, but after shutting it down the place gets cold pretty quickly. In other words he isn't holding the heat in. He goes through a 20lb bottle of gas at least once a week. We had a long Winter here this year and at $20-something a pop he's paying dearly for warm air. I've tried to tell him to put some insulation up in the ceiling and to cover those walls with osb but he's one of those stubborn mule types. Oh well, it's his money.
So getting back on track, if you are in a cold climate, make sure your insulation is up to snuff first.