Quote Originally Posted by waxthis View Post
My garage is a tad over 700Sq, well insulated and 45k is plenty...I would say up to 1000Sq... This may help you

http://www.heater-store.com/heater_calculator_info.htm
It's about 1,000sq ft w/tall ceilings, three windows (w/coverings), two doors and two overhead doors (one double wide) w/insulation panels and all is drywalled. House was built about 4yrs ago and is an energy efficient home so I hope some of that spilled over into the garage as they were building as well. I'm pretty immune to weather so I don't need it to stay 70 deg or anything... just a little warmer in the winter.