Outdoor Wood Furnace Info

All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: gardnert on March 06, 2012, 05:28:50 PM

Title: Outdoor stove too big?
Post by: gardnert on March 06, 2012, 05:28:50 PM
I am looking at buying a used heatmor 400ss that i found a really good price on. The stove is rated for 10,000 sq ft and my house is 2400 sq ft slab on grade, in floor heat. Is this stove too big for my application?  Thanks for any comments!
Title: Re: Outdoor stove too big?
Post by: johnybcold on March 06, 2012, 05:51:55 PM
Too big?? Is that possible?? It will problay burn more wood then a smaller unit but I would think it is better then oil , hopefully one of the pros will chime in here
Title: Re: Outdoor stove too big?
Post by: Scott7m on March 06, 2012, 06:00:08 PM
You can def be to big.....  If you have a huge stove it will idle many times longer them what it should and could lead to creosoting problems as well possibility of the fire going out.  It will also make itself very inefficient, because to keep enough wood in it to keep it from going out, it'd just to much wood and that again leads to creosote.

I always tell customers don't cram your stove full, it's wasteful and silly.  Just add enough to get you through to your next load time.  But I still have folks cram them full no matter the weather or conditions

What is considerd a good deal on that unit, kinda curious
Title: Re: Outdoor stove too big?
Post by: gardnert on March 06, 2012, 06:02:50 PM
1500$, which i thought was a good deal,  but im no expert and new to these units.
Title: Re: Outdoor stove too big?
Post by: Scott7m on March 06, 2012, 06:04:54 PM
Yes that sounds fair considering everything works....   The really bad part though is how much is involved in installing a heatmor vs any other brand, the sand and all that is just a mess.  If it was 1500 and didn't have to do anything but pick it up and move it, that'd be awesome
Title: Re: Outdoor stove too big?
Post by: gardnert on March 06, 2012, 06:10:15 PM
Thats basically what it is, pick up and move it. Everything is in at my house, it just needs to be set into place. I just bought my house and while the whole deal was going through, someone decided to steal the heatmor that was there.
Title: Re: Outdoor stove too big?
Post by: woodfuel on March 06, 2012, 06:14:58 PM
What if he's selling you the one that got stolen in the first place? JK That really sucks though. If you add outbuildings, that may be a good choice because of more sq ft.
Title: Re: Outdoor stove too big?
Post by: gardnert on March 06, 2012, 06:16:44 PM
Ha ha, i thought about that but its a different model
Title: Re: Outdoor stove too big?
Post by: Scott7m on March 06, 2012, 06:44:34 PM
You can't just pick it up.  You set it, and set the grates in the middle and then pour like 6-800 pound of sand around the center, it's weird but it may take more sand than that on a 400
Title: Re: Outdoor stove too big?
Post by: chadley on March 06, 2012, 09:07:05 PM
Interesting post.  I am buying a 10,000 sq foot stove as well and my house right now is 1800 sq ft but I plan on adding on a 2400 sq ft (or more) detached garage and finishing out my current garage (24x24) into a family room in the future, 

I am going with the larger stove so that it will meet my state's EPA regs. Anything over 350k btu does not have to meet EPA regs.  I'm curious to research more on oversized stoves. Anyone out there that has an "oversized" stove that can help out?
Title: Re: Outdoor stove too big?
Post by: gardnert on March 07, 2012, 08:40:50 AM
So would it cause me problems or would i get by without filling the firebox so full?
Title: Re: Outdoor stove too big?
Post by: Scott7m on March 07, 2012, 08:59:56 AM
Yea...  Maybe...   But with a big stove it's supposed to have a large heat draw.  With a little heat draw on a huge stove it will idle much longer than it normally would.  With seasoned wood you likely won't have a problem, but if your wood was a bit green it might not refire.

Have you looked at what I was talking about with all the sand?
Title: Re: Outdoor stove too big?
Post by: gardnert on March 07, 2012, 09:08:29 AM
Yes i kind of looked into it. My dad has this same model and he kind of explained it to me but i still dont completely understand how it all goes together.
Title: Re: Outdoor stove too big?
Post by: oldchenowth on March 08, 2012, 09:14:43 AM
For $1500, I would have a heated deck.  Margarita and umbrella in January just to work the thing a little bit.  I WOULD contribute to global warming if I had to.
Title: Re: Outdoor stove too big?
Post by: gardnert on March 08, 2012, 09:47:22 AM
Thanks for the help guys. And oldchenowth, how about a heated driveway so my 4  wheeler never has to plow again. Ha ha
Title: Re: Outdoor stove too big?
Post by: tbone on March 08, 2012, 12:19:34 PM
Gardnert,

I don't think you will have a problem as mine sits idle all day when its mild and after the sun goes down and the house cools, she fires right back up.  The 400 is a beast, I have one down the road from me.  You will probably only have to add fuel every 24 hours, which would be a sweet deal.  Don't be afraid of the sand and fire brick, once you get it set up and running, you shouldn't have to add sand again.
Title: Re: Outdoor stove too big?
Post by: Hydronix on March 18, 2012, 08:51:39 PM
Too big, NO. Its an OWB with lots of storage, its not like sizing a furnace or low mass boiler. An OWB is like a boiler and buffer tank in one. Is there a limit where you can go too big, well yes, if standby losses are more than 20%. Pretty much you burn one time a day or once every 2 days before you use all the stored btu's and are loosing more than your using. It would be a good idea to "overinsulate" the OWB to reduce standby losses. Check out some of the pictures from Garn's website, they actually encase them in some seriously insulated sheds. You could even get a view of the OWB's insulation quality with an infrared camera to see how its doing.
Title: Re: Outdoor stove too big?
Post by: Scott7m on March 18, 2012, 09:50:41 PM
Too big, NO. Its an OWB with lots of storage, its not like sizing a furnace or low mass boiler. An OWB is like a boiler and buffer tank in one. Is there a limit where you can go too big, well yes, if standby losses are more than 20%. Pretty much you burn one time a day or once every 2 days before you use all the stored btu's and are loosing more than your using. It would be a good idea to "overinsulate" the OWB to reduce standby losses. Check out some of the pictures from Garn's website, they actually encase them in some seriously insulated sheds. You could even get a view of the OWB's insulation quality with an infrared camera to see how its doing.

Lot different situation there....  U batch burn garns, there are a lot of issues that can arise from going to big and not batch burning