Shop Heat Solutions

Ideas and suggestions for heating a woodworking shop. March 26, 2008

Question
I'm looking for the best way to heat my shop. I have 1000 sq.ft. with no gas plumbed to the building. I've tried the propane tank setup, but it seems to give off an unpleasant/unsafe odor. A wood burning stove could heat it but I don't feel comfortable going that route. I know electric is expensive but I'm in California so it's only needed here and there. Can anyone recommend a good electric heater or other way to safely heat a cabinet shop?

Forum Responses
(Cabinetmaking Forum)
From contributor D:
edenpureheater.com makes one that will heat 1000sf.



From contributor A:
"I've tried the propane tank setup but it seems to give off an unpleasant/unsafe odor."

This would mean you had a gas leak. No gas leak, no problem. Many people use Modine Hot Dawg propane/natural gas hanging units. These are safe and work well.



From contributor B:
You might consider an electric flat panel heater(s). Go to peopleheaters.com. These panels are about an inch thick and typically mount to the ceilings. They provide a very comfortable radiant heat. A nice bonus is they have zero flame or glowing coils that could ignite finish fumes or airborne sawdust.

They are not a robust commercial unit, but for a smaller size shop such as yours, three or four panels would keep you nice and toasty I'll bet. They are 220 volt and are pretty easy to run through a programmable thermostat. The thermostat is a good idea because these panels are not a quick heat. They work more by warming the surroundings rather than heating the air like a furnace. If you could have them come up to temp 1/2 to one hour before working in your shop, you would enjoy the comfortable heat and warm equipment. In my shop, I have them set back to around 50-55 degrees when I'm not using the shop (nights, etc.) and come up to around 65 degrees when in the shop.

If I remember correctly, the panels are all two feet wide by one foot long increments up to maybe ten-twelve feet long depending on your space and heating needs. Let them know the general specs of your shop, ceiling height, number of windows, insulation, outside temp, etc. and they can recommend the size and number of panels you need. They seem fairly economical to operate because the radiant heat feels warmer at a lower temp than say a bunch of hot air blowing around.



From contributor P:
"These panels are about an inch thick and typically mount to the ceilings. They provide a very comfortable radiant heat. A nice bonus is they have zero flame or glowing coils that could ignite finish fumes or airborne sawdust."

So might they be at all applicable to use in finish rooms? (I'm thinking only of preheating and after-spraying curing.) I went to the website and found it pretty well useless. Lots of links but no real information.



From the original questioner:
Thanks for the info. The Eden Pure Heater claims to be capable of heating 1000 sq.ft., and is made overseas (the wrong sea), but it only costs $400. The People Heaters are made in Connecticut, are $275 for a 2'x8' panel, and they say you need one panel for every 100 sq.ft. Yes, their website needs help and the pictures they provide don't have me running to the checkbook.

I could get one Eden Pure and if it's not sufficient, buy another... $800. Or, spend about $2800 on 8 people heater panels ($300 for thermostat, $300 shipping).

Contributor B, you do seem happy with yours. I'm gonna think about it for awhile. Contributor D, do you use an Eden Pure yourself?



From contributor R:
Why are you asking wood butchers? Call a qualified HVAC person. My HVAC guy doesn't ask his peers how to build cabinets! :-)


From the original questioner:
That was my first route. His recommendation was one of those tube/strip heaters. I'm not sure of the proper name, although I do have one above the office in storage which I received for free. It just needs to be wired. It seems to be more appropriate for task heating in a small area. But you're right, I should ask another HVAC guy.


From contributor B:
That is more panels than I assumed you would need. There are a lot of factors to consider. I made the assumption that with your climate, you wouldn't be trying to heat your shop when it was 20 degrees outside. If you have a fairly uninsulated metal building type of shop, you will need something more robust. I have them in my shop but it is about 500 square feet and insulated. Once they have been on for a while, it is a nice comfortable heat. When I bought mine, I bought their woodshop series, which I think just means they are slight blems cosmetically and so they sell them for a little less. I did opt for the set-back thermostat, however, so that I can keep the temperature swings in the shop (at nights) down to a range that works well with these panels since they are slow to heat the room up.

As for a finish room heater, they could work, but remember they have a somewhat slow heat-up time if you are switching them on and off.

These panels are really low tech and no mystery. They are simply a thin aluminum panel for the face, behind which there is a layout of electrical wires something akin to the look of radiant floor tubing layout, and then backed up with about an inch of dense fiberglass insulation. The whole sandwich is surrounded with what amounts to no more than an aluminum picture frame type molding.



From contributor N:
When I started I built a shop about your size behind the garage. I used a gas-fired heater (just change the orifice for propane) that didn't need electricity. I did add a fan for a little better efficiency. I pulled air in from outside and exhausted out, both from the back. Mine was an Empire. I bought it from the local P & H shop.


From contributor S:
If you need to retrofit, you can run hot water baseboard off an electric water heater with a pump and expansion tank. Very cheap to set up and very efficient. No fuel refills needed and no exhaust fumes to deal with and no open flame. If you are going new, then you can do the same thing but run the loops in the slab for radiant floor heat.

Picture is our setup for in-floor heat. The only difference for radiant baseboard would be to run hard copper lines instead of the plastic in floor ones. Plus with that small of a space you don't need a manifold and multiple feeds. You would just need a single loop with one pump. We keep tank on at all times during winter but have it set up to a digital thermostat so it turns on when needed. If we need to override settings it is just hitting a couple of buttons.


Click here for higher quality, full size image



From contributor Y:
I have basically the same setup as what you show in the picture except I run my off of an on-demand water heater. How many square feet is your shop and what does it cost you to heat the shop on an average winter month? What size of water heater do you use in your setup?


From contributor S:
This was an add-on just for the finishing area, roughly 500 square foot. Rest of shop is forced air system. We also put in an outside air input vent so we don't draw warm air out of shop along with the dust.

The first year before we put this unit into spray area the heating bill was $6,000 in oil and gas (two furnaces) because we were drawing the warm air out of shop. The furnace ran nonstop during spraying.

After adding digital programmable thermostats, installing this system and putting in vent to draw in outside air, the bill is less than half that even with the increase in oil pricing. If the price was the same, I would think we are probably 1/3 of what it was before. In other words, it paid for itself the first year. The electric bill didn't go up either, since the blower unit didn't have to run full time on furnace it made up the difference to heating the water.

That was another thing with our setup. It is far away from water in building and has a sealed loop system. Every other year we replace coil and top off the water by hooking a hose up to it. I think it is a 50 gallon unit? I will have to check the BTU rating.

What kind of heater unit do you have? Does it have a holding tank with recirculating water and an exterior element on it? I bet you save a few bucks by not having to keep the core temperature up. I would be interested in replacing existing with your style unit when this one craps out.



From contributor Y:
I have a Bosch 117000 btu heat on-demand instant water heater. I bought if from Home Depot for around 500.00. I have a circulating pump that is wired to a thermostat. When the thermostat calls for heat, it turns on the pump and the water circulating through the water heater turns on the flame. My heating guy tells me that the Rinnai heaters are a lot more efficient than these Bosch units. I also have it plumbed into a wood stove that I built with a bladder inside it. It works but the temperature isn't constant enough to keep the slab at the right temperature. For a 2400 sq ft shop it runs me about 400.00 per month.


From contributor I:
I have a 1500sq ft shop. 14 ft drop ceilings. I put a wood stove in, and two 52" ceiling fans, and I'm happy with the heat. Winters don't seem to be that bad anymore in the Northeast. Mind you, I have a natural gas furnace, forced air, to boot! Don't like to use it because of the cost.