On Dec 20, 4:52�pm, "RBM" rbm2(remove wrote:
Don't know if there is a formula for this and I'm not looking for a typical
heat loss calculation. The scenario is this: Garage is 24' X 24' with 12'
ceiling. There is sheetrock and insulation in the ceiling and three walls.
The garage has two standard overhead doors. Temperature is aprox 32 degrees.
I want to raise the temperature to 60 degrees in about one hour. How many
BTU's do I need?

Thanks for any help, Roy

Easiest way is just to run the car for a while... sorry,
couldn't resist. Find it hard to believe you want to do this
electrically, unless, as another suggested, you have super cheap hydro
power. Might want to put foamboard on the doors, improve seals if
warranted.