Heating Woodshop

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Forum topic by BiologistAngler posted 01-28-2021 03:50 PM 722 views 0 times favorited 22 replies Add to Favorites Watch
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31 posts in 759 days

01-28-2021 03:50 PM

I have a detached garage space that I use as my wood shop, it is not heated or insulated at this time. I have the chance of installing a wood burning stove to heat it during winter months while I’m out there, otherwise I have to work in the cold. I’m worried about how the heating and cooling of the shop will affect wood movement and project pieces like tabletops. I won’t be out there every day, and when I am it is only for a few hours at a time. The real challenge working in the winter is finishing projects. I have no space in the house I can safely apply finishes because of fumes getting into the living space, it will be helpful to have a place that can be heated as coats of finish dry. My question is will the constant heating and cooling of my workspace make wood movement too unpredictable? I’m trying to get better at taking my time when dimensioning lumber (waiting for it to acclimate to shop and after planing, etc.) but if the shop is going up and down in temperature will that present too much of a challenge?

22 replies so far

View BurlyBob's profile


8492 posts in 3275 days

#1 posted 01-28-2021 03:54 PM

Something else to consider is condensation on metal surfaces like your table saw, causing rust issues.

View teetomterrific's profile


119 posts in 1371 days

#2 posted 01-28-2021 04:19 PM

If you cannot keep the shop within a reasonable working temperature range you will be constantly be fighting changes in wood moisture content and experiencing unexpected wood movement. I keep my shop at a constant 65 degrees all winter long with a Modine Hot Dawg HDS enclosed combustion heater. The enclosed combustion keeps it form introducing excess moisture into the shop from burning gas and also prevents combustion of VOCs from finishing and of course sawdust. It cost’s me an average of about $30 a month in gas to keep my shop comfortable 24×7. I do have the shop well insulated though. The up front cost for the heater and insulation was well worth it. I can work whenever I want and can be assured my projects will not warp or crack on me.

A wood stove seems like a terrible idea to me for a myriad of reasons not the least of which is the fire hazard. The inconsistency of the temperature and the requirement to feed the beast would be too much of a PIA for me.

-- Tom, Adams, TN

View bilyo's profile


1303 posts in 2112 days

#3 posted 01-28-2021 04:46 PM

Your best first step is to seal and insulate as thoroughly as possible. That will make all other measures to heat/cool much easier and less costly and more efficient. If you need to do finishing in the winter, you will need a system, much like in your house, that can safely and automatically maintain a proper temperature for many hours during application and curing. I question whether the wood stove is the proper system for that.

View splintergroup's profile


4687 posts in 2232 days

#4 posted 01-28-2021 04:58 PM

I heat my detached workshop with wood in the winter and living in the southwest, the humidity is never an issue as it currently hovering around the 20% mark. It is insulated and I’ll heat it up to about 70 on the weekends when I’m out there, otherwise It’s left unheated and it’ll settle around the high 40’s low 50’s. No problems whatsoever with wood movements, but again I’m not fighting humidity.

View Fred Hargis's profile

Fred Hargis

6834 posts in 3503 days

#5 posted 01-28-2021 05:03 PM

Your best first step is to seal and insulate as thoroughly as possible. That will make all other measures to heat/cool much easier and less costly and more efficient.

- bilyo

This^^^^^. I’ve worked in a occasionally heated workspace for sometime, and not had a problem. But that space was always insulated and the temps seldom fell below 40º. Once I had a furnace i kept the temps around 50º when I wasn’t working, and 65 when I am. BTW, One of the things I had early on was a wood stove. While i, too, think it’s more work getting the wood and such, along with the hazards involved and likely insurance issues…..there’s something really nice about working wood with the crackle of a fire going.

-- Our village hasn't lost it's idiot, he was elected to congress.

View woodbutcherbynight's profile


7739 posts in 3418 days

#6 posted 01-28-2021 05:21 PM

Small radiator heater can keep shop temp stable at 55 all night then warm to 65 with forced heat of some kind.

-- Live to tell the stories, they sound better that way.

View AlaskaGuy's profile


6398 posts in 3319 days

#7 posted 01-28-2021 05:23 PM

Seal, seal, seal …....insulate, insulate, insulate. Then choose a heat source

-- Alaskan's for Global warming!

View therealSteveN's profile


7241 posts in 1584 days

#8 posted 01-28-2021 05:38 PM

I’m in the humidity capital of Ohio, we have fluctuating humidity levels of up to 90’s and down to 20%. Sometimes within a few days of each other.

My shop has the houses old furnace, and it’s on LP gas. I leave it at 50 when I’m not out there, it uses surprisingly little fuel at 50. The win is I can go out, turn it to 65, and within a very short time be in shirtsleeves, comfy, and because I keep it at 50, the cast iron isn’t like a block of ice, that immediately numbs my fingers.

I haven’t seen any changes in the wood, as the furnace is also doing it’s thing for dehumidification, and I have a constant dripping out as it runs. I just have to empty my water container every few days. Running it straight outdoors, it does freeze in the cold, so I keep the wet inside in a sealed container tank.

Generally a furnace, and wood dust is not a good mix, but my HVAC guy had me build a 2 filter stack to mount the furnace on, so it’s up over where the dust layer hangs, and the intake air is twice filtered before it goes to the burn chamber. I’m 6’2” and the bottom of the furnace is about nose high on me. Fortunately my 12’ ceilings allow for the blower box they built on top.

If/when it fails, I’ll just swap to a standard LP hanging heater. Now that I have heat, I’m not going unheated again.

-- Think safe, be safe

View bondogaposis's profile


5950 posts in 3361 days

#9 posted 01-28-2021 06:01 PM

I have heated my shops with wood in the past have not had issues with wood movement. I live in a dry climate, though. How bad the daily fluctuations will be depend a lot on where you live and how cold your winter temps get. One thing that has been said is insulation will help a lot. It will help trap the heat you create and make it last much longer into the night and maybe even until morning to where your shop temperature will be warmer than the outside. That will help to even out any wood movement issues.

-- Bondo Gaposis

View BiologistAngler's profile


31 posts in 759 days

#10 posted 01-28-2021 08:34 PM

I was going to start a new thread but here goes: I may have another option; there is a side room to my house (log cabin) about 18’x18’ it has a stone floor and while the walls are not insulated, a ventless propane heater was installed that keeps it fairly well heated. This may be a possible shop space, but I had two concerns. The first is that I’ve read that these ventless gas heaters produce water vapor in the air as they burn gas (thus possibly messing with wood movement). I’m going to get a humidity meter so I can gauge what the humidity is in the room and how it changes with various settings on the heater. I wonder if this problem could be mitigated using a dehumidifier. The second concern is that as you can see, the heater burns gas behind a perforated mesh, and I’ would worry about saw dust clouds being a fire hazard. This may not be as big of a deal if I use vacuum collection at the dust ports of all machines.

View Lazyman's profile


6640 posts in 2397 days

#11 posted 01-28-2021 11:16 PM

If you have enough sawdust in the air to be a fire hazard, you have a bigger problem with air quality and your lungs that you would need to deal with.

I doubt that the occasional and temporary fluctuation in relative humidity as you heat and cool your shop will have a significant impact on the MC of any wood in your shop. Remember, the rule of thumb is that it takes about a year per inch of thickness for green wood to air dry so a few hours of lower RH while you heat it and and few hours of higher RH as it cools won’t be long enough for the wood to take in or give off a significant amount of moisture. You will see a greater impact due to the longer term average RH changes with the seasonal variation than these temporary fluctuations.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View Woodmaster1's profile


1656 posts in 3596 days

#12 posted 01-29-2021 01:42 AM

My 33×30 shop is heated with a 50,000btu ng bigmaxx heater. It cost me $120 a year to heat it at 70 24/7 from October to March.

View Badgerstate's profile


14 posts in 42 days

#13 posted 01-29-2021 01:48 AM

Ive got what I believe is an insulated 2-car detached garage (I say believe because I dont know that its insulated but even when its 20 degrees outside, the garage never gets below 40 degrees) and I just use a small, 1500w space heater.
Its plenty warm enough to keep the garage warm when I work out there but it doesnt seem like it effects the wood that I store in the garage (and I keep the wood on the bench, right next to the heater).

View BiologistAngler's profile


31 posts in 759 days

#14 posted 01-29-2021 08:30 PM

I measured the temp and humidity in my potential shop area that has the ventless heater. With the heater level at 2 out of 5, it is about 65 degrees F and 25% humidity. If that is accurate, I think that sounds ideal for a wood shop. The room even has a 230v receptacle in the corner that I can use for a dust collector.

View Foghorn's profile


1039 posts in 396 days

#15 posted 01-30-2021 12:57 AM

I’d recommend a direct vent LP or natural gas forced air overhead heater with a fully enclosed combustion chamber (no open flame). I chose a Modine Hotdawg for my last shop. Works great.

-- Darrel

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