Maine.
I'm looking to maintain heat in my small garage all winter because I don't like to go "fire up" the heater in a frozen garage, wait for it to warm up, then still have frozen tools, toes, etc. I currently have a real need to utilize my shop more in the winter and my tools are slowly deteriorating from condensation. I've done quite a bit of research and would like some input.
Garage specs:
14'x24' 10' ceiling
Concrete slab
2x4 walls
Fiberglass insulated.
9x8 insulated garage door (this is my weak link, I will be installing weatherstripping and additional insulation to the door)
I am in the process of adding 3" rigid foam insulation to the exterior and in the attic. Making it very tight.
I would like to go propane. I like it, seems to require less maintenance (correct me if wrong). I currently use a small wall mount propane heater, I own a few 100lb tanks that are all set up, lines, etc.
First I was looking at the Mr. Heater Big Maxx units which are reasonably priced but I got reading that having separate combustion heating is more desireable? So now I am looking at the Sterling GG45, which with the concentric vent kit is twice my initial budget. But it gets great reviews and I think it would be worth the investment.
Questions...
1. I know a heater that is too small will not be effecient. What about a heater that is too big? I'm thinking the 30k btu might be pushing it so I decided the 45k would be a better choice?
2. Am I to understand that by drawing combusion air from outside that this heater will not need to draw cold "make up" air into my heated area? increasing effeciency over the Big Maxx and similar heaters?
3. What temperature should I maintain in the winter to avoid excessive condensation, then when I am in the shop I can turn it up.
Any input is appreciated.
Thanks.