Wood Stove for Shop/Garage Questions

[CutterComp]

First, let me say I am new to woodstoves and new to the forums here. In an attempt to not be that new guy who posts up the dumb "Uhhh, what stove should I buy?" questions, I did my best to educate myself through the stickied threads at the top of the forums and of course, a bunch of other internet reading and videos over the past month or so.

So this thread is more of along the lines of getting feedback on the solution I've reached based on my own muddling. I'm hoping that if I'm on the wrong track, you folks can set me right.

Here's the background: I'm in southeast PA and setting up a machine shop in my garage. The garage was built in the '50s and is built into the hillside, so that the back wall of the ground floor is fully underground. So figure about half of the ground floor is actually underground which is great for insulation (terrible for water ingress... but that's a different matter). The building is two stories plus a walk-up attic. First story is cinderblock, the upper stories are wood framed and the second story, which was originally built as an apartment, is fiberglass insulated. The stairways are currently open with no walls or doorways, although I have temporary plastic sheeting at the top of the stairs leading up from the ground floor. The building is 25' x 25', so 625 sq. ft. per story. There is one 8 ft garage door at the front of the ground floor that I will be insulating shortly!

I have 5 acres, mostly wooded, which is one of the reasons I started looking at woodstoves. I don't mind the labor involved and the wood is free once I get ahead of things and have time to get a good quantity split and dried.

A potential downside I see to a wood stove is that the shop willget cold every night when I'm not there and the machines will take quite awhile to get warm the next day, with so much thermal inertia. A constant thermostatically controlled heat source would be nice, but I don't think I can afford to heat the shop 24/7 with another heat source, be it oil, propane... etc. If it becomes an issue, using wood alone, perhaps I can supplement with another heat source overnight to keep the place at least in the 50-60 range. Thoughts on this are welcome.

I'm mostly concerned with heating the ground floor. I'm sure through convection the second floor will stay semi-reasonable too. I will need to wall off the attic steps because the attic is uninsulated.

It's my understanding that I won't need a big stove for what amounts to 1250 sq feet (625 per floor). I've had a number of people I know recommend Jotul and so I started searching the local used classifieds for a Jotul F3. I found a very nice refurbished one for $950. It's a non-cat stove which I want.

I plan to use Duravent Durablack single wall stovepipe straight out the top of the stove to a support box in the ceiling above the stove, then Duravent double wall stainless 6" Class A pipe straight up from there on up and out the roof.

Pics are worth a thousand words, so I have included some pics below of the garage. I plan on placing the stove in the rear corner of the groundfloor where you currently see the bare blue/green air compressor tank.

Thoughts and recommendations?

Thanks.

 

[bholler]

Be aware using a solid fuel burning appliance in a garage is against code in the us. Because of that any insurance claim made regarding that stove will most likely be denied. If you are ok with that risk that's up to you

 

[Jan Pijpelink]

Be aware using a solid fuel burning appliance in a garage is against code in the us. Because of that any insurance claim made regarding that stove will most likely be denied. If you are ok with that risk that's up to you

I was waiting for this.

 

[bholler]

I was waiting for this.

Highbeam will be along soon to tell us how that isn't a garage so the code doesn't apply here. And no that car isn't really parked there either

 

[Jan Pijpelink]

Highbeam will be along soon to tell us how that isn't a garage so the code doesn't apply here. And no that car isn't really parked there either

That's why I waited for it. First thing I saw was the car and the half dozen bottles of oil. Not to mention all the sprays.

 

[bholler]

That's why I waited for it. First thing I saw was the car and the half dozen bottles of oil. Not to mention all the sprays.

And the gas cans

 

[Jan Pijpelink]

I am not familiar with all the codes and stuff. But as a petroleum chemist I think, OMG, WTF!

 

[weatherguy]

Be aware using a solid fuel burning appliance in a garage is against code in the us. Because of that any insurance claim made regarding that stove will most likely be denied. If you are ok with that risk that's up to you

I was going to say it but didnt want to steal Bhollers thunder.

 

[Seasoned Oak]

The hardest part will be finding 2Sf of empty space.

 

[nola mike]

That's not a garage, it's a basement.

 

[Sawset]

Installing Wood Stove in Garage | WETT Inspections for Barrie | Orillia | Midland | Alliston

Installing a wood stove in a garage is allowed by current rules and guidelines. Proper care must be taken to ensure flammables and combustibles are safe.

wett-inspection.com

 

[begreen]

"An appliance shall not be installed in a location where a corrosive atmosphere, flammable gas or vapour, combustible dust, or combustible fibres may be present."

"...the wording clearly prohibits a solid-fuel-burning appliance within a garage that is being used for what would be traditional vehicle storage purposes. It is for this same reason that some insurance companies will not provide coverage if a solid-fuel-burning stove is installed within a garage."

 

[peakbagger]

I will leave the safety debate to the pros. What I see is potential for lots of rusty precision equipment and high wood consumption. I agree that the ground is a lot warmer than the outdoors but its still a major heat sink with uninsulated block walls. If the ground temp is 50 F when you are trying to heat the space to 70 the large amount of wall and the ground behind sucks the heat right out of the room. While the heat is traveling into the ground, the moisture in the ground is getting sucked into room. The amount of water vapor that can be stored in the air increases as the indoor air temp goes up. This is not a problem until the space cools down but once the space cools down to the dewpoint of the air in the room the vapor goes back from a vapor to liquid. Same thing happens when I put a cold drink on the counter during the summer the surface is cooler than the dewpoint and then the vapor in the air condenses on the cold surface.

Ideally the walls need vapor barriers and insulation covered with durable wall covering that will hold up to machine shop operations. The floor also should have at a minimum a vapor barrier, unfortunately if you have water seepage just putting down a floor coating system may not work as the water under it may lift the coating. The bummer is most people want concrete floors for durability so that limits laying down insulation and vapor barrier unless you do so and then pour a new floor on top of it.

Once you deal with the thermal loss and vapor ingress you then end up with smaller stove and fuel supply. The space should hold temps longer and the dewpoint will be lower in the space so unless you are doing machining operations that introduce a lot of vapor in the air overnight condensation will be less of an issue but to really deal with it you need standby heat source to keep the place heated all the time above a reasonable dewpoint. Keep the water vapor out and you can maintain a lower temp but keep the open walls and floor and you need to increase the standby temp. There are dewpoint controllers to automate the setpoint but best approach is deal with the source of the moisture.

 

[WinterinWI]

Sounds like you want constant even heat, if so you might want to reconsider and look for a BK or other cat stove.

I have a non-cat in my shop (not a garage) and love it. You get good at quick warm ups. If you do a decent job insulating, you'll lose less heat than you think overnight. The uninsulated concrete floor will probably be your biggest enemy, but there isn't much you can do about it at this point.

 

[WinterinWI]

"An appliance shall not be installed in a location where a corrosive atmosphere, flammable gas or vapour, combustible dust, or combustible fibres may be present."

That description disqualifies wood stoves from being installed in just about any house I've ever been in. The average house has hairspray, aerosol cleaners, rubbing alcohol, gas lines, combustible fibres (furniture) ect ect ect.

 

[RandyBoBandy]

Does the OP have natural gas? The garage heaters/shop heaters you can buy from the box stores have thermostats to control and maintain a constant temp. I’ve been lightly looking into this myself. I’m just not sure how well they work from an economic stand point. I don’t know anyone who has one in their garage.

 

[Kevin Weis]

What bholler said, but I'm sort of in the same boat but my garage is new. Opting for propane fired heater forced hot air that the unit is mounted above on the rafters. I'm only in there a few times a week to actually work on anything so I can just turn it on when I need it so that fits the bill. All in all about 2000 to get it done.

 

[CutterComp]

Be aware using a solid fuel burning appliance in a garage is against code in the us. Because of that any insurance claim made regarding that stove will most likely be denied. If you are ok with that risk that's up to you

I'm sure this seems awfully ignorant on my part but being new to this, I honestly didn't know that. I will be sure to look into the code, it's good knowledge to have obviously. Where can I find this information? Also, what is the reasoning behind disallowing solid fuels in a garage? What is it about liquid fuels that makes them safer? Living out in the countryside, natural gas is not an option, so that leaves me with propane or heating oil or waste oil.

The hardest part will be finding 2Sf of empty space.

ha, I'm in the midst of rearranging most of the building, so things are in a chaotic state but I assure you it won't be so cluttered when I'm done.

I will leave the safety debate to the pros. What I see is potential for lots of rusty precision equipment and high wood consumption. I agree that the ground is a lot warmer than the outdoors but its still a major heat sink with uninsulated block walls. If the ground temp is 50 F when you are trying to heat the space to 70 the large amount of wall and the ground behind sucks the heat right out of the room. While the heat is traveling into the ground, the moisture in the ground is getting sucked into room. The amount of water vapor that can be stored in the air increases as the indoor air temp goes up. This is not a problem until the space cools down but once the space cools down to the dewpoint of the air in the room the vapor goes back from a vapor to liquid. Same thing happens when I put a cold drink on the counter during the summer the surface is cooler than the dewpoint and then the vapor in the air condenses on the cold surface.

Ideally the walls need vapor barriers and insulation covered with durable wall covering that will hold up to machine shop operations. The floor also should have at a minimum a vapor barrier, unfortunately if you have water seepage just putting down a floor coating system may not work as the water under it may lift the coating. The bummer is most people want concrete floors for durability so that limits laying down insulation and vapor barrier unless you do so and then pour a new floor on top of it.

Once you deal with the thermal loss and vapor ingress you then end up with smaller stove and fuel supply. The space should hold temps longer and the dewpoint will be lower in the space so unless you are doing machining operations that introduce a lot of vapor in the air overnight condensation will be less of an issue but to really deal with it you need standby heat source to keep the place heated all the time above a reasonable dewpoint. Keep the water vapor out and you can maintain a lower temp but keep the open walls and floor and you need to increase the standby temp. There are dewpoint controllers to automate the setpoint but best approach is deal with the source of the moisture.

Thanks for the good info. I know well that the lack of vapor barriers in the walls and floor are killing me. Fixing that, including tearing up and pouring a new floor is in the plans, but that's no small task and I just have to do the best I can with what I've got for now. I run a dehumidifier 24/7 and since I started doing that I haven't had much issue with machines rusting.

Sounds like you want constant even heat, if so you might want to reconsider and look for a BK or other cat stove.

You're saying a cat stove for the longer, more consistent burns? Still may not help me much overnight though.

That description disqualifies wood stoves from being installed in just about any house I've ever been in. The average house has hairspray, aerosol cleaners, rubbing alcohol, gas lines, combustible fibres (furniture) ect ect ect.

Hmmm indeed... haha

Does the OP have natural gas? The garage heaters/shop heaters you can buy from the box stores have thermostats to control and maintain a constant temp. I’ve been lightly looking into this myself. I’m just not sure how well they work from an economic stand point. I don’t know anyone who has one in their garage.

Unfortunately no natural gas out in the boondocks here. I've been told to stay away from propane if possible because it's expensive and the price is unpredictable. But maybe I should reconsider. I would prefer to meet code for insurance purposes. A waste oil heater is an interesting option but I personally don't come close to producing enough oil to run one and I've heard guys can struggle to find a good supply.

 

[Jackfre]

Sorry to pile on, but while I understand the desire to have a wood stove in the space it will be illegal and yes, you can hide it from the insurance company, well, at least until you need the insurance adjuster to visit, at which point they will walk and you are left holding the bag. It happens. They are not your friend. The other thing is space, as noted. You will be doing a doe-see-doe with that stove every time you walk in there. I think you would be best off harvesting and selling the firewood and using that dough to pay the propane bill. I have a Rinnai EX22 in my shop and it is excellent.

 

[bholler]

I'm sure this seems awfully ignorant on my part but being new to this, I honestly didn't know that. I will be sure to look into the code, it's good knowledge to have obviously. Where can I find this information? Also, what is the reasoning behind disallowing solid fuels in a garage? What is it about liquid fuels that makes them safer? Living out in the countryside, natural gas is not an option, so that leaves me with propane or heating oil or waste oil.



ha, I'm in the midst of rearranging most of the building, so things are in a chaotic state but I assure you it won't be so cluttered when I'm done.



Thanks for the good info. I know well that the lack of vapor barriers in the walls and floor are killing me. Fixing that, including tearing up and pouring a new floor is in the plans, but that's no small task and I just have to do the best I can with what I've got for now. I run a dehumidifier 24/7 and since I started doing that I haven't had much issue with machines rusting.



You're saying a cat stove for the longer, more consistent burns? Still may not help me much overnight though.



Hmmm indeed... haha



Unfortunately no natural gas out in the boondocks here. I've been told to stay away from propane if possible because it's expensive and the price is unpredictable. But maybe I should reconsider. I would prefer to meet code for insurance purposes. A waste oil heater is an interesting option but I personally don't come close to producing enough oil to run one and I've heard guys can struggle to find a good supply.

The quote begreen provided is directly from the section of irc concerning solid fuel heaters.

 

[WinterinWI]

The quote begreen provided is directly from the section of irc concerning solid fuel heaters.

"An appliance shall not be installed in a location where a corrosive atmosphere, flammable gas or vapour, combustible dust, or combustible fibres may be present."

In that case, to be code complaint, you'll need to start advising members that in order to install a wood stove in their house, the only way they can do so is to remove the following from their house:

Hairspray, flammable cleaners, aerosols, non-dairy creamer, flammable furniture, rubbing alcohol, nail polish/remover, LP or NG gas lines, ect.

 

[Ludlow]

If you have an integral garage in your house you cant have a stove?

 

[Sawset]

For an attached garage here, code required a 2hr fire rated drywall, attic door, and entrance door sealed from all other areas (living area, attic etc). Given that, then putting in the stove here, there was no mention of garage, living area, and stove in the same context, just the stove and living area. Am thinking a parked car in the basement here with a stove above, would be an issue.

 

[bholler]

In that case, to be code complaint, you'll need to start advising members that in order to install a wood stove in their house, the only way they can do so is to remove the following from their house:

Hairspray, flammable cleaners, aerosols, non-dairy creamer, flammable furniture, rubbing alcohol, nail polish/remover, LP or NG gas lines, ect.

As long as it isn't in the same room it's fine. Notice it says location not structure.

 

[bholler]

If you have an integral garage in your house you cant have a stove?

What sawset said is exactly correct. As long as the garage is seperated it's fine