Heating the Shop in a Cold Climate

A discussion of the choices for heating a large, poorly insulated shop, including radiant gas burners, wood-fired boilers, and more. March 22, 2013

I have a 2400 sq. ft. cabinet shop with 14' ceilings (about 34,000 cubic feet of air volume). The space is fairly air tight, or at least there's no major air leakage. But there's little insulation and it's concrete block construction.

I currently have a Modine oil burner hanging from the ceiling. The thing makes a lot of noise and the oil cost is quite high. Without much roof insulation, it stays cold down near the concrete floor and the place is uncomfortable unless I've run the oil burner for a long time. The white noise is so loud from the burner and blower that I'd almost rather be freezing.

I've heard of the propane radiant heaters that mount on the ceiling and radiate heat with zero noise and zero electricity consumption, heating objects rather than the air. Can anybody recommend a system that would be appropriate for my size shop and take a guess at the relative cost to oil heating? Any particular products I should check out? I would consider a portable model if it put out enough heat to keep me warm in the 1,000 square feet I spend most of my time - at the work bench, chop saw, table saw, CNC, etc.

Forum Responses
(Cabinetmaking Forum)
From contributor B:
I have a radiant tube in my shop that is 1400 sq ft with a 17 ft ceiling. My tube is 135,000 btu that will warm my shop in a matter of minutes. I ran it the first year on propane and was quite surprised at the cost. I had 2 large cylinders that cost $425 for the first fill up. 28 days later they refilled the tanks to a tune of $380 and it was the same all winter. The next summer I converted to natural gas and it now runs $80 to $100 a month. I keep my shop about 60 degrees all the time. Radiant tubes work best on a high ceiling and you should be great for height.

From contributor X:
Differences if you own the building or are renting. Raw or finished ceiling with a complete open area. What would your insurance man say?

From contributor J:

Can't help you on the radiant heat. Both shops I've worked in have had gas fired forced air and I can't imagine wanting anything else! It's simple and as close to maintenance free as it gets. I have a programmable thermostat set so it kicks on about an hour before I get in and it runs fairly quiet even though the furnace is right in the corner of the shop.

Costs are similar to what contributor B pays for my 2k sq. ft. shop with 10' ceilings in an uninsulated concrete block building. If you have the gas company spread the cost out over the year, a little over $100 a month.

If you have access to gas, a furnace isn't too bad. My landlord just replaced mine last year and I believe it ran something like $2500 installed.

From contributor T:
I am running forced air as well. Just a regular furnace in the corner, running off of LP. I clean it out really well with compressed air each fall, and have it serviced every other year. I shut the pilot light off during the summer months.

My shop is about 1000 square feet with 9' ceilings. I am located in the mountains of central Vermont. The building has decent insulation but I have a crappy overhead door (get a weatherstripping kit - they help!). If it is sunny, my shop will almost warm up on its own. I have 3 9' long windows along the front wall. I will run the heat in the morning, and cut it back in the afternoon if it is in the upper 20's or 30's. In the fall, I don't even bother with heat unless I am curing finishes. My heating bill ran about $650.00 last winter.

From contributor P:
My shop is 2200 sq ft and I heat it with a woodstove. It's great in so many ways. Planning on also hooking up a loop through it to install radiant heat for my spray booth floor.

From the original questioner:
I'm renting my space. Trust me, I'd love to have a woodstove for obvious reasons, but I can't do it without permission from the landlord and fire department. Ain't gonna happen. Natural gas isn't on the street, so that's not an option either. I will probably have to stick with the oil tank for now.

From contributor K:
I'm in Maine. I have an outdoor wood boiler. Love that thing. All wood scraps go in and I can get a 24 hour burn unless it's wicked cold. Expensive up front, but in a few weekends I can have enough wood cut up to last the winter.

From contributor T:
Insurance companies typically won't allow use of a woodstove in a cabinet shop. I would love to have one, and of course I live in a state where 90% of people heated their homes with woodstoves up until 1990. However, too many people who just have no clue managed to start fires, so they are considered dangerous by the powers that be.

From contributor J:
I really like the idea of an outdoor wood boiler! If I last long enough to ever buy my own building, I may just have to look into one. I hate having to give away all the hardwood scraps.

From contributor E:
In my 2400 sqft shop, I ran a duct straight down from the peak to about three inches above the floor. Before the last section I put in a duct fan with a switch. This pulls the warm air down. Two of these have made a temperature difference for me.

From contributor A:
Insulation is far more important than the heat source. I get the noisy heater; however, if it's not running as often, it won't be as noisy. Portable radiant may be a temporary solution. I would be slightly concerned about dust getting on the radiators. However it's a very local solution. Do you own the building?

From the original questioner:
I rent. I will get a portable radiant heater for this winter and see how it goes. Most of my time is spent in one small area of the shop, so this should help.

From contributor E:
I also have a wood boiler. I put radiant floor heat in but didn't insulate under the slab. That was a big mistake - the ground acts like a big heat sink. All it would've taken was a thin metallic bubble insulation to break that contact. I use a forced air heat exchanger instead. Now if only briquetters weren't so expensive and I could burn my sawdust also.

From contributor L:
We've got radiant tube heat. Much better than the forced air unit heaters in my old place. Extremely quiet, and very even heat. Concrete block buildings are horrible to heat. Your body radiates to the cold surfaces. Make a deal with the landlord to share the cost of insulation.