Another heater size dilemma

[Dart53]

Hello all,

I'm about to install a Hot Dawg or similar type ceiling mounted heater to my unheated garage here in MA and am struggling (maybe overthinking) to determine the right size.

The garage is 22'x23'x8.5' with two 9'x7' insulated ovhd doors, four dbl-hung windows(48 sf) and an insulated man-door(17.8 sf). The walls are 2x4 construction and are sheetrocked. Only one wall, the 23' one without the ovhd doors is insulated (R-13). The ceiling is sheetrocked and insulated (R-30). The concrete floor is uninsulated.

I've received several estimates from contractors proposing heaters from 30K to 60K Btu's. I've checked out a couple online calculators but they seem pretty general and don't take into account doors or windows. Using them I get 30K-45K heaters.

Should just go with the average and get a 45K heater? Any suggestions?

 

[dogdas]

45 is big and a 60 is stupid. With that size you can get away with the 30. You only have 4300cf. I have on my attached a 75 at 9000sf and that is fine. The last thing you want is the unit cycling too much. That just beats the **** out of things. Your garage is insulated well so I would go with a 30 and be done with it, its not that cold in MA.

 

[Dart53]

Thanks for taking the time to respond, Dogdas. I think I'll go with a 30K unit.