# Choosing a shop heater



## beevis (Jul 30, 2010)

Hey all,

I'll soon be insulating my 20'x20' shop with 3" rigid foam panels (about R20) in walls and ceiling.

I am thinking of a ceiling hung Modine style propane heater because I don't want to sacrifice floor space, and because they are readily available used. Only downside I can see is that propane is pricey.

But, what about the combustion chamber on these? Aren't they essentially open? Even with dust collection is there a risk of fine dust particles ignited and causing a fire?

My shop is in my detached 2 car garage, so a lot of other options are impractical.
I could theoretically do an oil fired furnace, but they seem to take up a lot of space.

Thanks for any advice.
B


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## wapakfred (Jul 29, 2011)

If you buy a used one it will likely draw room air in for combustion, so yes it's basically an open chamber. Newer ones can be had with direct vent (outside air for combustion and a sealed chamber) and is what I have in my shop. This one is a Sterling Garage Guy, but it's pretty much the same as a Modine. Even so, I think the chances of fire are very slim even with an open chamber; although spraying lacquer in the shop would be highly discouraged. More likely, seems to me, is the chance of dust buildup on some electrical component causing a malfunction in the furnace. that's the main reason I bought the direct vent model. Sterling claims it increase efficiency as well, but I doubt it would be enough to measure without laboratory instruments. As for cost, this year the price of LP is pretty low (I paid 99¢/gallon) but of course last year was a completely different story. To heat my 24×32x8 shop (R19 walls and R40 ceiling) I burned 150 gallons last year, heating to 65ºwhen I'm in there (most days for 8 hours) and 55º at night. Still cheaper than electric, except for the initial installation.


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## BillWhite (Jul 23, 2007)

Look at the oil filled radiator style elec. heaters. That's what I use. No flame, fumes, danger from goofy stuff.
Might not be the best from an economic standard, but I sure feel safe with them.
Bill


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## timbertailor (Jul 2, 2014)

One thing most do not consider is that propane creates a very humid environment when burned. May not be an issue for some but it is worth mentioning.


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## TheGreatJon (Jan 9, 2015)

I also have a detached 2 car garage. Mine has a natural gas line extended from the house and the unit is hung from the ceiling like you describe. It was installed when I moved in and I honestly haven't inspected it closely, but it does draw the shop air through it with a fan. It's been really dusty in there and I've never smelled anything burning.

Natural gas is cheap. If you can feasibly run a line, I highly recommend it. My shop warms very quickly.


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## paratrooper34 (Apr 27, 2010)

Ben, I also live in Western Mass and can tell you that propane prices are the lowest I have seen in the five years I lived here; under 2.00 per gallon. If you own your own tanks, you can get some super deals.

Consider a two piece Heat/AC unit. Half of it mounts on the wall inside and the other half outside. Those units are a good option for heat and AC when other options don't work.


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## conifur (Apr 1, 2015)

Moisture from a propane heater is only a problem if it does vent to the exterior.


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## Finn (May 26, 2010)

> Look at the oil filled radiator style elec. heaters. That s what I use. No flame, fumes, danger from goofy stuff.
> Might not be the best from an economic standard, but I sure feel safe with them.
> Bill
> 
> - Bill White


I heat my 22×14 shop with one of these but it really does not get all that cold here in West Texas. Gets down to about 15° occasionally. I would not worry about using a Modine heater either.


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## conifur (Apr 1, 2015)

The electric oiled filled heaters are the least effective/efficient based on a Consumer Reports rating, the milk house style with a fan are the most, and around WI they sell for 17.00$. I have used one in my insulated, unheated basement shop of 15×15ft and worked fine.


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## AlaskaGuy (Jan 29, 2012)

The only way your going to have a dust explosion in your shop from an open flame heater is to have a cloud of dust so thick you couldn't see or breath much. So forget about that problem.

Here's a pretty good article of different heaters for woodworking shops written by Woodworkers Journal.

http://www.woodworkersjournal.com/best-way-to-heat-a-workshop/


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## SamuraiSaw (Jan 8, 2013)

The shop I've been in for the last 2 years has a Modine gas heater that is over 30 years old. During the winter it keeps the shop at around 65 degrees with no issues. In addition to copious amounts of sanding I spray finishes as well.


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## Knothead62 (Apr 17, 2010)

Whatever you buy, make sure it has a fan to circulate the warm air. Our gun club has a LP heater in the indoor archery range which is about 20X60. Turn it on and the fan warms the range in just a few minutes.
The oil filled heaters that I have seen are radiant only. Would take a long time to warm your shop. Good idea for the insulation.


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## DrTebi (Jun 16, 2009)

> Look at the oil filled radiator style elec. heaters. That s what I use. No flame, fumes, danger from goofy stuff.
> Might not be the best from an economic standard, but I sure feel safe with them.
> Bill
> 
> - Bill White


That's what I use too. It doesn't get that cold here though. Depending on how cold it gets, you may need a large model though.

A real-life example: Due to renovation I currently live in my living room, which is about 20×12 feet, insulated, with three windows. I use a cheapo electric oil-filled heater, 1500 watts max. It takes a while to heat up the room, but once it's warm, I just leave it on about 1/2 setting 24/7 and it keeps the room comfortable. However, it hasn't been below 40° F here…!

This is not the most economical solution, but in my opinion the simplest and safest.
With a bit of calculation (energy cost, how many hours you run the heater, how many watts it uses) you can quickly figure out how expensive it would be.

Heaters that blow hot air are probably more efficient, but it dries up the air, blows dust around, and makes me sick…


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## revanson11 (Jan 5, 2012)

My shop in Minnesota is 20' x 28' with 6" walls with fiberglass batts along with 16" of blown in insulation in the ceiling. I use a 35,000 BTW Empire direct vent LP wall heater. If I run my ceiling hung air filter when I first go out to the shop I can heat the space from 58 degrees to 65 degrees in about 30 minutes, even when it is -30 outside. As was pointed out earlier here the price of propane is less than 1/2 that of any type of electric heating system. If by chance you have natural gas in your area even better although with how cheap LP is this year it might even be cheaper than natural gas.


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## English (May 10, 2014)

I heat my shop with a thru the wall mounted window unit heat pump. 11,000 btu cooling and 8000 btu heating with electric backup strip heat. Very economical. I set it at 55 when not in the shop and bring it up to 62 when working.

My shop has r15 in walls and r19 overhead. R6 on the rollup door and double pane windows.

It adds about $20 to the monthly utility bill.


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## beevis (Jul 30, 2010)

What do you guys think about a ventless propane infrared heater? There is one for sale near me used that looks good, but I know very little about that technology. Would that be dangerous around dust?

Thanks


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## wapakfred (Jul 29, 2011)

I wouldn't worry about the dust, but rather the moisture it puts into the air. I had one in my garage at the last house, it was insulated but no vapor barrier in the ceiling. ran one of the ventless heaters one day and for some reason had to go into the attic for something. The roof deck was dripping heavily with the moisture that had condensed from the heater. I removed it that day and gave it away.


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## WoodNSawdust (Mar 7, 2015)

Last summer I installed a Mitsubishi ductless heat pump unit. The outside unit looks like a regular AC unit and the inside is a low profile unit. In last August's heat and the current cold (lows in the teens highs in the twenties) it is costing me around a dollar per day to run. In both the heat and cold it had no problems keeping the shop at 60 degrees. The unit plus installation ran around $3000.


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## conifur (Apr 1, 2015)

Propane heater if not vented to the outside dumps about a gallon of water in your heated space for every 100K BTUs burned.


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## Gene01 (Jan 5, 2009)

That's what I use. Brand name ProComm. My shop is 24 X 36 and the heater has 5 plaques. It gets down below 0 at night and our water well tank and pumps are in the shop. So, it's heated 24/7. Last winter, we used 200 gallons.
There's been no problem with dust. I'll occasionally blow it out.


> What do you guys think about a ventless propane infrared heater? There is one for sale near me used that looks good, but I know very little about that technology. Would that be dangerous around dust?
> 
> Thanks
> 
> - Ben


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## eflanders (May 2, 2013)

I had a ventless unit in my old garage shop. I lived in SE WI at the time and it kept things warm enough to work in but it took quite a while for it to heat things up from a cold start. I quickly learned that if I didn't maintain at least 60'F in there that I experienced issues with condensation and rusted equipment.


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