Heating a workshop

September 29, 2009 10:30 AM

What's a good portable and safe way to heat a detached garage that's used as a workshop.

I have a detached garage that I use for woodworking and electronics projects. Since there will be a lot of sawdust around, I don't want to use a traditional space heater because of fire fears.

An oil-filled portable radiator seems like it might work, but it looks like they take a while to heat up.

Is there a better solution that I'm over-looking?

posted by drezdn to grab bag (10 comments total)

Try a kerosene heater, there's all kinds of models - they actually blow out hot air, as opposed to those radiators that only heat surrounding air. Those work great in a room with a drafty window or something, so it might do ok in a drafty garage, but it'll be slow to heat the space from scratch. Those kerosene heaters are what my mechanic friends usually use, most commonly I see them using those torpedo-looking models but there are smaller models that look kinda like overblown camping lamps.
posted by eatdonuts at 10:37 AM on September 29

How about a garage heater?
posted by caddis at 10:39 AM on September 29

An oil-filled portable radiator seems like it might work, but it looks like they take a while to heat up.

We use oil-filled portable heaters in all the main rooms of our house, and I've never noticed that they take long to heat up. They produce a very comfortable, radiant heat that fills the whole room. I'm guessing they would be perfect for a garage/workshop (if it's a two-car-sized garage, you might want two heaters -- one of each side -- for a more even distribution of warmth). Best of all, they're not a fire hazard and most units have an automatic shut off feature if they get tipped over.
posted by amyms at 10:45 AM on September 29

What eatdonuts is talking about. One advantage, you can get lots of heat without having to run 240V service to the shop, although depending on how fancy you make your shop you probably want that for some of the bigger tools anyway.
posted by caddis at 10:45 AM on September 29

If you go with kerosene or other combustion don't forget to vent:

VENTILATION
WARNING: PROVIDE A FRESH AIR OPENING OF AT LEAST THREE SQUARE FEET (2,800 SQUARE CM) FOR EACH 100,000 BTU / HR RATING. PROVIDE EXTRA FRESH AIR IF MORE SPACE HEATERS ARE BEING USED. THE MINIMUM VENTILATION REQUIREMENTS MUST BE FOLLOWED TO AVOID RISKS ASSOCIATED WITH CARBON MONOXIDE POISONING. MAKE CERTAIN THESE REQUIREMENTS ARE MET PRIOR TO OPERATING SPACE HEATER.
Example: A 200,000 Btu / Hr (58.6kw) space heater
requires one of the following:
• a two-car garage door [16 feet (4.88 meter) opening]
raised 5 inches (12.7 cm)
• a single-car garage door [9 feet (2.74 meter) opening]
raised 8 inches (20.3 cm)
• two, 30 inch (76.2 cm) windows raised 15 inches
(38.1 cm)

posted by caddis at 10:52 AM on September 29

I think you'd enjoy reading some heater reviews on Cool Tools:

Cool Tools: Dyna-Glo Pro Heater

Cool Tools: ProCom Unvented Propane Heater

They aren't really just single product reviews; they discuss alternatives etc.
posted by Perplexity at 11:21 AM on September 29

Somewhere out on Make I have seen people use solar. Not photovoltaics, but big columns and rows of soda cans spraypainted black. The air circulates up through a carefully controlled channel and emerges, hot, at the top. Not that I'm Mr. Hippie Solar or anything, but if you're really concerned about flaming hydrocarbons, it's an alternative.
posted by adipocere at 11:30 AM on September 29

I recommend the electric oil heater. They're cheap (mine was $19 at Lowes), require no ventilation, and they don't force air circulation, so that means it's not apt to suck in sawdust and either get jammed or start a fire. Plus, you can easily move it around. If you set it to max heat and then turn it down once it's warm enough, it doesn't take too long to warm up the room. I estimate you'll reach the temperature you want in roughly 30-45 minutes, which I think is fine.

The more wattage the heater uses, the faster it will reach the desired temperature. Energy efficiency isn't so much what this is about as current load, since this is based on using a thermostat to heat oil and then radiate the heat to the room from there. My model draws 1500 watts if you switch both elements on, or it can draw only 700 or 800 watts if you only flip on one element, so it's adjustable.

I recommend you stop by the hardware store, see if you can find a cheap one, and make sure you can return it. If it's too slow for you, just take it back. Obviously, it's too heavy to ship.
posted by mccarty.tim at 11:51 AM on September 29

First I use a kerosene "salamander" style heater to knock the chill out of my garage. But I don't like running it for long periods of time because it burns a lot of fuel and it creates carbon monoxide (which is why you are suppose to run them with a door or window partly open for ventilation).

Once the garage is warmed up I switch to one or two other heat sources. I have two radiant (quartz) heaters that sit on my workbenches and face my front and back sides. They do an excellent job of keeping me warm as long as I stay at my workbench. They are also cheaper to run than the typical electric hot air heaters.

When it gets colder and I need more heat I also run a propane catalytic heater that attaches to the top of a 20-lb. propane tank. It puts out a lot of heat and it can be run indoors safely, although you can get burned if you get too close to it.

Much of the floor is also covered with 2x2-foot interlocking foam mats that are about an inch thick. They've been very durable and even though they make cleaning up sawdust (or swarf in my case) a little harder, they also make it more comfortable to stand for long periods and they help insulate my feet from the cold concrete floor.

I've also closed off a portion of the garage with tarps to help hold in the heat. The storage loft above my work area also helps a lot with that.
posted by 14580 at 12:12 PM on September 29

IANA professional woodworker, but my understanding is that fine sawdust can be explosively flammable, so you should avoid anything that produces an open flame. Same with certain kinds of varnishes.

Personally I use an oil heater and it works fine - you just have to turn it on a few minutes before you go out into the garage. They don't take that long to heat up.
posted by kenliu at 6:04 PM on September 29