garage furnance reviews - Mr Heater

lhfarm · Oct 9, 2009

RonMar said:
I just finished insulating my 24X24 grage early this last spring. It is a whole different space now, and requires very little heat compared to what it used to.

Your heat demand is going to be a LOT less after you insulate, so something properly sized for that will surely be inadequate without the insulation, and something sized for no insulation will be way to large once the insulation is up. I am not sure what your coldest temps are and how much wind you have, or your insulation plans, but 75,000 BTU/HR sounds like a LOT of heat for a well insulated space... I heat my home thru the winter in the PNW primarilly with a pellet stove kicking out 12,000 BTU/HR... As mentioned, best to start with the ceiling, but untill you get to it, a visqueen vapor barrier stapled across the bottom of the rafters will make a Huge difference in room comfort by just stopping warm air from rising above the rafters.

Those heaters look like they are designed to mount up near the ceiling, but personally, I don't like the idea of any open flame heater in a space where I work on fueled vehicles.

Good suggestions. I'm debating the size. It can be really cold in central Indiana, with the rare sub-zero days. I like the vapor barrier on the ceiling idea. It has already gotten chilly here (an early fall?) and I doubt I can get going on the insulation for a few more weeks.

These style heaters mount within an inch of the ceiling and are rated for garage installation. But I understand your safety concern.

Thanks,

Pilot · Oct 10, 2009

I understood that ceilings shouldn't have a vapor barrier, although I really don't know why. Our well insulated house doesn't have a vapor barrier there, nor did our last house. Check with an expert. Visqueen stapled there until you are ready to put up sheetrock is probably a great thing.

dave1949 · Oct 10, 2009

Pilot said:
I understood that ceilings shouldn't have a vapor barrier, although I really don't know why. Our well insulated house doesn't have a vapor barrier there, nor did our last house. Check with an expert. Visqueen stapled there until you are ready to put up sheetrock is probably a great thing.

Ceilings - at least in areas with cold winters, should definitely have a vapor barrier. I prefer 6 mil blcak plastic to visqueen - it is much tougher and less prone to deteriorate.

The reason for the vapor barrier is heated air can contain more humidity than cold air. As the heated air rises, carrying the humidity with it, it with pass through sheetrock, wood, etc into the attic area. As it moves through the insulation layer and begins to encounter cold air, the dew point is reached and moisture condenses out. The moisture saturates the insulation, can even form an ice layer.

This makes the insulation useless and can lead to rot, etc.

Vapor barriers are always installed on the heated side of walls and ceilings.

Dave.

radman1 · Oct 12, 2009

I have a Modine 75,000 btu heater in my 24x24 well insulated, detached shop. Way overkill and heats it up in 10-15 minutes to 70F from 35-38F. 75,000 btu should be fine for 24x40 shop and is probably more ideal. I use a low temp thermostat and keep it at 35-38F in the winter and store the stuff I don't want to freeze.

dodge man · Oct 12, 2009

I also have a heater very similar to what you are looking at for a 28'x30' garage, and yes it is oversized. The guy that put it in for me said it was to big, but it was only like $50 more than the smaller one. It is really nice having it oversized, as I keep it at 40 degrees most of the time and it warms it up to 60 degrees in just a few minutes.

CinderSchnauzer · Oct 12, 2009

Since you have the NG line, another potentially inexpensive option might be a used house furnace. I have an office / washroom area about 8x15, in the shed, with a storage deck above. There is a furnace up there with just one large output duct that blows downward into the shed. I just set the stat for 55F and turn up manually if more heat is needed.

ultrarunner · Oct 12, 2009

I've got an old Reznor ceiling mounted furnace with blower... I think it's 40,000 Btu.

It will heat the shop up in about 10 minutes... I keep the pilot off unless I am going to use it.

One of my friends uses only an infrared heater over his bench... he likes it because it keeps the bench in his tools warm to the touch...

In the old days I just used my red-neck heater... I would run my errands and pull my car into the garage... it made a noticeable difference in comfort with the car just sitting there with the motor-off and the heat dissipating...

coobie · Oct 13, 2009

lhfarm said:
Good suggestions. I'm debating the size. It can be really cold in central Indiana, with the rare sub-zero days. I like the vapor barrier on the ceiling idea. It has already gotten chilly here (an early fall?) and I doubt I can get going on the insulation for a few more weeks.

These style heaters mount within an inch of the ceiling and are rated for garage installation. But I understand your safety concern.

Thanks,

I live in southern Michigan and just had another pole barn built(24X34X13).I went with the spray foam insulation about 3 inches thick(ceiling & side walls)I went with a unvented 28,000 btu LP gas wall heater,it about drives you out of the barn on the lowest setting.coobie

lhfarm · Oct 14, 2009

Thanks for all the good information. I've found a Modine dealer just over the state line and I am going to try to make a road trip to save shipping. I'll do a follow-up report after I make my purchase and at least start the install.