EPA vs non EPA wood stove in shop

[skidud]

I am putting a stove in my shop this winter and am starting to do a little C/L shopping. I'm hoping for a little advice on what I should be looking for. Insurance is on board and I understand the risks of a stove in a shop so please don't turn this into a thread about how stoves in shops are a bad idea.

First off, my shop area is going to be the front corner of a larger pole building. 27x34 with 6" studs and R-19 insulation on the walls and ceiling. It will be on a 6" concrete slab. I live in northern Ohio and we saw temps in the negative 20's last year.

I don't plan to burn wood 24/7 but rather fire up the stove before I go out there to work. I may or may not supplement the heat with some type of electric heat to keep the building from freezing. I don't know if there are non EPA airtight stoves but for this post, I am considering EPA stoves to be airtight and vise versa.

My questions are as follows:

Would a non airtight stove heat up faster or be better for a flash fire? I ask because my dad's old Fisher seems to get up to temp in a quarter the time as my Napoleon 1900. I'm more efficient in the long run but efficiency isn't my primary concern here, fast heat is.

Does burn time rely more on fire box size or will an airtight stove offer better burn times, how much of a difference is there?

Would a radiant or convection style stove be better?

Now the dumb question, are the differences between convection and radiant stoves obvious (since I'm looking at used stoves) and how do I tell?

Any other thoughts would be appreciated.

 

[jharkin]

Most of the time when I hear issues about stove in shops due to insurance and codes its specifically aobut stoves in garages where flammables like gasolin,etc is stored. If you have building inspector and insurance go-ahead sounds like you are good.

Does burn time rely more on fire box size or will an airtight stove offer better burn times, how much of a difference is there?

Just to eliminate any occlusion, I think you are asking about EPA certified vs pre-epa. there where a lot of pre-epa stoves marketed as "airtight" since they where sealed enough that you can regulate the heat of fire by the air intake. The difference is an epa stove has some sort of secondary combustion system.

To get a non-airtight stove you have to look back at 1800s era box stoves, like an old potbelly or franklin fireplace, etc.


To answer your question, a modern EPA stove may or may not have a longer burn time on a load than an old stove, but given the same amount of wood it will be throwing more heat. (you could take an old smoke dragon and choke it way down low for a long smoulder but its not heating much).

Would a radiant or convection style stove be better?

Now the dumb question, are the differences between convection and radiant stoves obvious (since I'm looking at used stoves) and how do I tell?

All stove give off at least some heat both ways. Radiant stoves like your typical cast iron Jotul, VC or soapstone Woodstock etc give off more radiant heat obviously so they work best when everything to be warmed up is line of sight.

Stoves marketed as convection will add a blow to help heat the air in the room by convection faster. (like a Blaze king, Lopi, Englander, etc with a blower).

Some convective stoves take this a step further having an inner firebox surrounded by a decorative (sometimes iron) jacket, and use the blower to force air thought the space in between. One example I can think of here are the Pacific Energy iron jacketed stoves. These stoves give off the least amount of radiant heat.



Having said all that, for a shop that you need to warm quickly you have two concerns -
1- You want to bring the air temp up fast
2 - Even once the air is heated up all the equipment will still be very cold and act like a giant heat sink making the space still feel cold.


So I think you want a stove with a strong convective element that also radiates to help warm the mass of the room (so something with a blower that's not double jacketed). You want a stove that heats fast (iron or even better steel, not soapstone) and you want a stove that's most efficient at hot short/medium duration fires (so burn tube style non-cat more suitable than a catalytic).


Honestly this setup sounds like the perfect recipe for a simple steel box burn tube stove with a blower. Bigger the better. Like and Englander NC-30 or similar.

 

[Jags]

I'm gonna cut right to the chase...in a cold shop with cement floors you need firepower. Not only the cement floors but the steel benches and tons of tools and bolts and whatever else is in your shop is cold. Real cold...and dense.

I am a backer of EPA stoves, but there ain't many on the market that will beat an old papa bear or aunt Sara for raw btu's in a hurry. I have a big old steel box in my shop. Its a homemade unit. I ain't proud of it (cuz its consumption is a down right sin), but it is a beast. It works for me because I get shop time in small bursts. For this type of use I don't know that the difference between Convective or radiant will make a bunch of difference. Its all about the BTUs. I would probably think differently if my shop was used more consistently.

I am looking for a cheap NC30 to replace my steel box. I think it is a guilt thing.

 

[spirilis]

SOme convective stoves take this a step further having an iner firebox surrounded by a decorative (sometimes iron) jacket, and use the blower to force air thought the space in between. ONe example I can think of here are the Pacific Energy jacketed stoves. These stoves give off the least amount of convective heat.

nitpick, I think you mean "These stoves give off the least amount of radiative heat" there.

 

[jharkin]

nitpick, I think you mean "These stoves give off the least amount of radiative heat" there.

correct, that was a typo. fixed.

 

[Lumber-Jack]

I put an older larger non EPA wood stove in my shop. It's actually an old insert, but I have it in a free standing configuration. I went with the older non EPA stove for no other reason then it was cheap. I got the stove and a bunch of insulated chimney from my neighbor for $100, and considering how well it does the job it was heck of a deal.
I can't get long overnight burns out of it like I can with the EPA stove in the house, but I can get my shop from sub zero temps to comfortable working temp in about a half hour. (My shop is 24' x 20'), and I can get the place sweltering in a couple hours.
The wood stove is the only heat source I have in there, but I have managed to keep it from freezing in there for the last 3 year. Got lots of stuff I don't want to freeze stored in there. I don't have to have a fire in there every day, but when it is particularly cold out I'll try to get a fire going whether I'm using the shop or not, just to keep it from freezing in there. On days where it hangs just below freezing I can often get away with a big fire every 3rd or 4th day just to keep some residual heat in there. Like Jags says concrete floors act as big heat sinks, but that can work to your benefit too. If you can get keep that wood stove going good for a few days the concrete will absorb a ton of heat and slowly release it back up into your shop. It may not keep it room temperature, but it can keep it from freezing for a few days even when it's very cold outside.
To heat the shop up quickly you'll want as large a stove as you can get with a fan behind it to blow the heat around.

 

[Bigg_Redd]

Your shop is just over 900 Sq Ft and is well insulated. . . I'd say the very worst stove would heat it just fine.

 

[Highbeam]

I have a woodstove in my 30x60x14' tall pole barn. You are getting bogged down by the details. If it is legal to install a pre-epa stove in your shop then it will work just fine, so will an epa stove, airtight or nonairtight is meaningless since even the newest non-cat stoves are full of holes. My permit required an EPA certified stove so I chose the biggest one I could find and I really like the NC30 from home depot.

When you get a big 3+CF stove rocking at 700 degrees it will be making just as much heat as any 3+CF stove at 700 degrees. There's no magic and the radiant/convection argument is bogus as well. Heat is heat.

When you, or I, start up a fire in a 30 degree barn you won't raise the temperature of the air for quite some time. You will be using the stove like a campfire to warm your body in close proximity. As the day goes on you may raise the air temp but don't count on it.

Here's a picture of mine running. The walls are all finished now and insulated, the slab has 2" of foam all around it. The ceiling has plastic but no insulation yet.

 

[Bigg_Redd]

First off, my shop area is going to be the front corner of a larger pole building. 27x34 with 6" studs and R-19 insulation on the walls and ceiling.

Are these numbers for the shop or the pole building?

 

[begreen]

Heat is not just heat. A 3 cu ft unbaffled pre-EPA stove is going to waste a lot more heat up the flue. That is why the attitude was to put on single wall pipe and a stack heat robber on the old stove to recoup heat lost. The 30NC is significantly more efficient at putting the heat into the room.

 

[jharkin]

Not to mention that a blower can make a big difference in how quick to warm up the air in the room. that's why stoves without blowers struggle more in houses with a lot of small rooms where you have to push air around, vs a big open space that the stove can heat all the furniture etc radiantly.

 

[jeff_t]

The Hotblast furnace in my basement, that is no longer connected to the ductwork, takes it from 50ish to tee shirt temp in an hour or less. No insulation and a drafty bilco door, about 1300 sq ft of basement, and 300 or so of crawl. The blowers are rated at 550 cfm each, and it moves a lot of hot air.

Hard to beat for a quick warm up.

 

[begreen]

A wood furnace in a shop is a good idea for large areas, especially if the supply can be ducted to get heat throughout the space.

 

[jeff_t]

If it's going to go cold at night, everything is going to be cold. It takes a long time to warm that stuff up. The quickest way to get to a comfortable temp is to move a large volume of warm air.

 

[Highbeam]

Heat is not just heat. A 3 cu ft unbaffled pre-EPA stove is going to waste a lot more heat up the flue. That is why the attitude was to put on single wall pipe and a stack heat robber on the old stove to recoup heat lost. The 30NC is significantly more efficient at putting the heat into the room.

False. Heat is heat. It will take more wood to get the 3cf box hot due to low efficiency but once the box is hot it makes just as much heat as the next hot box. As such, the 30NC is NOT more efficient at putting heat into the room it is more efficient at getting heat out of a given amount of wood. Basic stuff.

If you close your eyes BG, can you tell one 3CF hot box from another?

 

[skidud]

Wow, I didn't think I would have any replies at this point. The pole barn is 36x54 with a 10x27 lean to on the side. My shop area is 27 deep and 34 wide which includes the lean-to. I will have the entire "shop" area insulated but the rest of the barn will be uninsulated.

I currently heat my home with a Napoleon 1900 and I can't complain with the poor location I have it in. However, I do notice that it takes a very long time to feel any substantial heat out of it. Once it's hot, I can really put out some warmth but getting it there is no fast process. I would think it's considered convective since it has sheet metal shrouds on the sides and a blower. While the stove is fine for my home and my heating needs there, I think it would make a lousy stove for my garage unless I were going to keep it burning 24/7 in which case it would probably be fine.

I am gathering that bigger is probably better. That seems to make the most sense in that I could get more heat faster and get a longer burn (if chocked down) should I want to fire it up in the morning for an evening project.

One more question, will a modern EPA stove put out the same amount of heat as quickly as a non-EPA air tight? I can get firewood fairly easily and am not concerned that it takes a little more wood to stay warm if it can get me warm faster. I am a little concerned about finding something that is big enough and affordable, something for around $300 to $400 in an EPA certified unit.

 

[Highbeam]

A wood furnace in a shop is a good idea for large areas, especially if the supply can be ducted to get heat throughout the space.

That would be ideal. The huge surface area of that heat exchanger and the forced air through it would extract lots of heat from the same size box.

 

[begreen]

False. Heat is heat. It will take more wood to get the 3cf box hot due to low efficiency but once the box is hot it makes just as much heat as the next hot box. As such, the 30NC is NOT more efficient at putting heat into the room it is more efficient at getting heat out of a given amount of wood. Basic stuff.

If you close your eyes BG, can you tell one 3CF hot box from another?

We mean the same thing, the more efficient burn means less heat going up the stack. If I open my eyes and read the flue thermometer the difference is pretty apparent. Some stoves are more efficient radiators. This is why many cast iron stoves have ribbing or a textured surface to increase the radiant surface area.

 

[Highbeam]

Wow, I didn't think I would have any replies at this point. The pole barn is 36x54 with a 10x27 lean to on the side. My shop area is 27 deep and 34 wide which includes the lean-to. I will have the entire "shop" area insulated but the rest of the barn will be uninsulated.

I currently heat my home with a Napoleon 1900 and I can't complain with the poor location I have it in. However, I do notice that it takes a very long time to feel any substantial heat out of it. Once it's hot, I can really put out some warmth but getting it there is no fast process. I would think it's considered convective since it has sheet metal shrouds on the sides and a blower. While the stove is fine for my home and my heating needs there, I think it would make a lousy stove for my garage unless I were going to keep it burning 24/7 in which case it would probably be fine.

I am gathering that bigger is probably better. That seems to make the most sense in that I could get more heat faster and get a longer burn (if chocked down) should I want to fire it up in the morning for an evening project.

One more question, will a modern EPA stove put out the same amount of heat as quickly as a non-EPA air tight? I can get firewood fairly easily and am not concerned that it takes a little more wood to stay warm if it can get me warm faster. I am a little concerned about finding something that is big enough and affordable, something for around $300 to $400 in an EPA certified unit.

Do you already have a chimney in the barn? The flue can get very expensive.

 

[HotCoals]

Wow, I didn't think I would have any replies at this point. The pole barn is 36x54 with a 10x27 lean to on the side. My shop area is 27 deep and 34 wide which includes the lean-to. I will have the entire "shop" area insulated but the rest of the barn will be uninsulated.

I currently heat my home with a Napoleon 1900 and I can't complain with the poor location I have it in. However, I do notice that it takes a very long time to feel any substantial heat out of it. Once it's hot, I can really put out some warmth but getting it there is no fast process. I would think it's considered convective since it has sheet metal shrouds on the sides and a blower. While the stove is fine for my home and my heating needs there, I think it would make a lousy stove for my garage unless I were going to keep it burning 24/7 in which case it would probably be fine.

I am gathering that bigger is probably better. That seems to make the most sense in that I could get more heat faster and get a longer burn (if chocked down) should I want to fire it up in the morning for an evening project.

One more question, will a modern EPA stove put out the same amount of heat as quickly as a non-EPA air tight? I can get firewood fairly easily and am not concerned that it takes a little more wood to stay warm if it can get me warm faster. I am a little concerned about finding something that is big enough and affordable, something for around $300 to $400 in an EPA certified unit.

A double barrel wood stove if ok for your install would be perfect and cheap and put out heat the fastest by a long shot.

 

[jharkin]

False. Heat is heat. It will take more wood to get the 3cf box hot due to low efficiency but once the box is hot it makes just as much heat as the next hot box. As such, the 30NC is NOT more efficient at putting heat into the room it is more efficient at getting heat out of a given amount of wood. Basic stuff.

If you close your eyes BG, can you tell one 3CF hot box from another?

Sorry HB, but its not that simple. Yes "heat" is a universal concept, the measure of how much thermal energy a body contains.. However, your perception of heat from the stove is dependent on the mode(s) of heat transfer between the stove and your body, and there are 4 different ways that happens. The % of heat transferred by the stove via each mechanism can vary based on how the stove is designed.

Convection (natural or forced)
Conduction
Radiation
Advection

http://en.wikipedia.org/wiki/Heat_transfer

 

[skidud]

I don't even have the doors on the barn yet or the floor poured. I just found out yesterday from my insurance that they didn't care if I installed a wood burner. I've been giddy about the news ever since and can't help but look at C/L for a good deal on a nice stove. I was convinced, to the point that I didn't even bother to call until yesterday, that my insurance wouldn't allow a wood stove in my shop. I couldn't believe they said it was fine since I already was paying more for the one in my house. My insurance includes one wood stove and apparently a second one in my shop doesn't matter. We have no enforced codes to speak of where I live so really the insurance was my only concern.

I've found used class A pipe on C/L different times. I would like to get everything as cheap as possible so I'm starting my shopping early before I'm in a bind to get it. I obviously need to know what size to buy which means I need to have my stove purchased before I try and buy any pipe.

I've found a couple of really good deals on wood furnaces and may look more into that option. I don't know how practical that would be for my application but the prices I'm finding makes it kind of tempting.

 

[Bigg_Redd]

So if the area you intend to heat is 900ish sq ft and insulated with R19 then nearly any stove will produce sufficient heat in a timely manner.

If you're not too concerned with looks keep your eye out for inserts. They make great shop heaters and often sell for less on the used market.

 

[HotCoals]

Sorry HB, but its not that simple. Yes "heat" is a universal concept, the measure of how much thermal energy a body contains.. However, your perception of heat from the stove is dependent on the mode(s) of heat transfer between the stove and your body, and there are 4 different ways that happens. The % of heat transferred by the stove via each mechanism can vary based on how the stove is designed.

Convection (natural or forced)
Conduction
Radiation
Advection

http://en.wikipedia.org/wiki/Heat_transfer

What he is saying is it doesn't much matter what the stove is or the matter of how the heat it comes off it they all can put out great heat if fed the wood.
It comes down to how much wood you can put in it and how big a fire you can have to get great heat fast.
I tend to agree. There are only so many btus in a pound of wood and however many of those btus you can keep from going up your flue is more relevant to me.
To me the thinner the box around the fire the faster the heat transfer also.
Interesting discussion though. Cheers!

 

[bholler]

If it was me i would look for a plate steel stove with a blower but not a full convective jacket on it that way you get both good radiant and convective heat. One thing to look at is what size outlet it has i would look for one with 6" because you will spend allot more on the stack and if you want to change it out later 6" will give you more options. And no heat is not heat there are different ways of heating and they work very differently.