Suggestions for heating 21'x44' shop

[bob_mp]

Greetings,
I am looking at options for heating my new shop. The ceiling in the center is 13'. I live in the Bay Area in California. I'll keep the shop heated in winter to high 50's, to control humidity, all the time and to a higher temperature when I am working out there. Separated combustion a must have.

I was planning on a Modine Hot Dawg 75, near the back of the garage, with separated combustion air. I am concerned about how well a single heater will distribute heat more-or-less evenly in this space.

A few thoughts came to mind:

1. Does it make sense to have two heaters of smaller size on opposite ends of the shop? The heat will be more even for sure. Not the cheapest option.

2. Use a radiant tube heater? I expect the heat would be pretty uniform. Perhaps something along the lines of a Re-verber-ray tube heater?

3. One heater and a big *** fan, something like a Big *** Fan ISIS to be specific.

Suggestions most welcome.

Thanks,
Bob

 

[Shop Specialties]

The Hot Dawg 75 would be overkill. I would go with the Hot Dawg 45 on one end blowing towards the garage door and call it good. If you want a quicker recovery when the big door opens and closes go with the Hot Dawg 60. One 56" ceiling fan in the center that has adjustable speed so you can turn it way down.

 

[ForceFed70]

For best heat distribution, you'll want the heater blowing in the "long" direction of the shop. You'd also place it about 1/3rd of the way across the building instead of against a wall.

Finally, I'd reccomend a ceiling fan to help move air.

 

[bob_mp]

Thanks guys.

I noticed Modine makes two versions of the 60k separated combustion heater -- one with a propeller and one with a blower.

The blower version has a longer heat throw. It's also considerably more expensive, particularly as compared to the 45k unit without the blower. Is the blower option worth the extra expense?

For a new install, any suggestions on using a concentric vent versus separate vents for combustion air and exhaust.

Best,
Bob

 

[ForceFed70]

Sorry, I don't have experience with the different fan types so can't say if it's worth it. Although I'd still reccomend a ceiling fan vs upgrading to a blower.

Why the seperated combusion? Are you planning to regularly deal with flammable vapors in your garage? Most people seem to get by fine with non-seperated.

 

[bob_mp]

No, but I worry about gas fumes related to leaks/accidents.

When replacing the engine in my truck, 12 years ago, I forgot to tighten the fuel injector supply manifold. After trying to start the engine a few times, I started smelling gas. Then I really started smelling gas.

There was gas all over the floor from the fuel system leak, an astonishing amount, actually. If there was a source of ignition in the garage, I suspect the situation would have ended very badly.

I don't know how to gauge the risks of a separated combustion versus regular heater. The peace of mind is worth it for me.

Bob

 

[Shop Specialties]

Mount it 8 foot off the floor and you will be fine. In 22 years of selling and servicing waste oil heaters up to 500,000 BTU I have never had a customer go boom from a fuel leak/fumes.

 

[BadgerBoilerMN]

First, a Manual 'J' heat load to properly size the heat source.

I would only consider a two-stage infrared tube heater with combustion air from outside.