I currently have a York 92k BTU output gas furnace in the garage. It takes up a lot of floor space I'd like to free up. I also have concerns about pulling combustion air from so low (about 22.5") and flames for the burner so low. This furnace will keep it as warm as I want and is probably overkill. The garage is 24'x30'x10', walls are R13 and ceiling is R3 rigid foam. I'll put R19 unfaced batts above the rigid foam in the ceiling soon.
I'd prefer to keep the existing 4" B vent and use a ceiling mount garage heater. I was looking at the Sterling GG heaters as you can convert them to separated combustion with an adapter on the intake port on the rear of the heater. I'd prefer to retain the existing B vent through the ceiling and roof, and run an separate intake vent (likely through the wall) if I go that route. It seems if venting vertically B vent is acceptable for most of the ceiling mount garage heaters. What I'm not sure on is that when going to a separated combustion model, or even the same model but adding a separate fresh air intake (Sterling GG) it seems like a concentric vent may be required. I'd rather use my existing double wall B vent, I don't see why adding a separate intake through the wall would have any effect on exhaust venting requirements but some of what I've read suggests it does. Can anyone clarify this, maybe specifically for the Sterling GG or Modine HDS units?
Beyond that, what BTU should I be looking at? Any specific heaters that would be good for my application? Is separated combustion worthwhile? I'd rather not spend the extra time reworking the chimney and roof penetration,while it's an option I prefer a quick and easy install.
I'd prefer to keep the existing 4" B vent and use a ceiling mount garage heater. I was looking at the Sterling GG heaters as you can convert them to separated combustion with an adapter on the intake port on the rear of the heater. I'd prefer to retain the existing B vent through the ceiling and roof, and run an separate intake vent (likely through the wall) if I go that route. It seems if venting vertically B vent is acceptable for most of the ceiling mount garage heaters. What I'm not sure on is that when going to a separated combustion model, or even the same model but adding a separate fresh air intake (Sterling GG) it seems like a concentric vent may be required. I'd rather use my existing double wall B vent, I don't see why adding a separate intake through the wall would have any effect on exhaust venting requirements but some of what I've read suggests it does. Can anyone clarify this, maybe specifically for the Sterling GG or Modine HDS units?
Beyond that, what BTU should I be looking at? Any specific heaters that would be good for my application? Is separated combustion worthwhile? I'd rather not spend the extra time reworking the chimney and roof penetration,while it's an option I prefer a quick and easy install.