gift
Unofficial Companion Guide to the Rocket Oven DVD
will be released to subscribers in: soon!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com pie forums private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • Anne Miller
  • Pearl Sutton
  • r ranson
stewards:
  • paul wheaton
  • Burra Maluca
  • Mike Haasl
master gardeners:
  • John F Dean
  • jordan barton
  • Greg Martin
  • Carla Burke
gardeners:
  • Jay Angler
  • Leigh Tate
  • Steve Thorn

Pellet stove heat capture?

 
Posts: 75
2
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hello Everyone,

I had grand plans for an RMH in my shop but circumstances have kept me from building one. Instead I bought a second hand pellet stove. It has proved to be almost adequate. I am frustrated with the amount of heat that goes out the exhaust.

As the unit has a forced air exhaust, draw is not a big concern. I am considering plumbing the exhaust from the stove into a steel 55 gallon drum then venting the drum outside. That would give me some "hang time" for more heat to be kept inside the shop.

Do you see any problems that may arise with this setup? Do you think that it will make enough difference to be worth the trouble?

Thanks.

S.
 
pollinator
Posts: 233
Location: N.E.Ohio 5b6a
129
food preservation homestead ungarbage
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
As long as it is really tight and I had a good CO detector I would be fine with it.  One thing I have learned is the volume of nasty gasses from anything burning can be dangerous.  I would check and make sure the burner unit is in good working order.  I was looking at a couple different designs at the farm science review and could put my hand in any of the exhausts with out any trouble at all.
 
Rocket Scientist
Posts: 4435
Location: latitude 47 N.W. montana zone 6A
1495
cat pig rocket stoves
  • Likes 6
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi Steve;    
I think your not going to gain enough and you might run into issues with venting from the barrel out.
Use a ceiling fan to move the heat you do get all around.
Any stove (other than a rmh)  is sending vast amounts of heat up up and away...  nothing to do about it, its the nature of the beast!

So what might the circumstances be that keep your grand plan from happening?
 
gardener
Posts: 1504
Location: Westbridge, BC, Canada
407
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 5
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Greetings Steve,   I have operated 2 pellet stoves for over 8 years now and have thought of the same thing. Never quite got around to it though ever since I built my own RMH.
If you do decide to try this experiment, do make sure that all the seams are hermetically sealed. Even a pin prick hole will spew out exhaust due to the exhaust gasses being under positive pressure and cause a potentially dangerous situation. As previously mentioned, detectors are a must.
With a RMH or any passively drafted stove being under negative pressure for all but the first minute or so will not have this problem.
 
Posts: 80
Location: 5,000' 35.24N zone 7b Albuquerque, NM
50
hugelkultur forest garden building rocket stoves woodworking greening the desert
  • Likes 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thank you for this thread, Steve! I have a similar situation and would love to experiment safely.
I bought the pellet stove about 15 years ago for my workshop that is not heated. After reading about rocket stoves (Wisner & Wisner), I thought about simply venting the stove exhaust pipe through a 10 foot cob bench and out the wall of the shop. Of course this would not be a RMH but it would be a beautiful warm cob bench and might hold more heat in the room.
Any additional suggestions and/or cautions for melding the pellet stove and the RMH (with or, preferably, without the oil drum) would be gratefully appreciated.
 
gardener
Posts: 3543
Location: Cincinnati, Ohio,Price Hill 45205
464
forest garden trees urban
  • Likes 5
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Rather than messing with untested materials in  the exhaust path, perhaps you could stick to stove pipe and, taking advantage of the forced draft, strip the heat out of the chimney using mass, either solid chunks of stuff or water.
 
pollinator
Posts: 1533
Location: Canadian Prairies - Zone 3b
394
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Or just a much longer stove pipe inside the building to act as a radiator. All the old-time buildings did this.

Edit: DUH, I should pay attention in class. This is what William was suggesting, and it's a good idea. Gotta capture more of that flue gas heat without messing up the stove's operating requirements for airflow, cooling etc.
 
Posts: 221
30
  • Likes 3
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I ran the flue of a 700 gallon Taylor water furnace into and out of a 55 gallon drum as a transition from a horizontal to a vertical chimney.
I ran it for three years without incident and then took off the clamp and barrel end to clean the flue, the fly ash build up was amazing!
There was probably at least 1/3 of the barrel filled with ash, on retrospect it probably was acting as an insulator and limiting the radiation from the barrel.
As far as draft, if the barrel is cold it will hinder draft but as long as the barrel is above ambient temperature it will assist. I would expect it to cool , and heat quickly as smoke is introduced.
Since most pellet stoves are forced draft I would think it would work fine, as a way of maximizing your exposure a baffle forcing the smoke through a twist or up and over a center divider may be useful.
+1 on the CO detector, it would be an awfully stupid way to perish when detectors are so cheap.
 
Bill Haynes
Posts: 221
30
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
For what its worth I think this would be a good idea to try with propane, and oil (Toyostoves, etc)
 
Bill Haynes
Posts: 221
30
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
So for max bang for the buck,.....
Could ya put stainless racks in there, and a temp monitor, and use hardwood pellets, to smoke the Thanksgiving turkey, and the Christmas ham!
 
Steve Smyth
Posts: 75
2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Bill Haynes wrote:So for max bang for the buck,.....
Could ya put stainless racks in there, and a temp monitor, and use hardwood pellets, to smoke the Thanksgiving turkey, and the Christmas ham!




Hmmmm... Max bang for the buck?

Out here, I can buy a 40# bag of softwood pellets for $4. I can buy a 20# bag of hardwood pellets for $16.....

I'm not very good at math but my gut says stick with the softwood pellets.
 
Steve Smyth
Posts: 75
2
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thanks for all of your input.

The reasons for buying a pellet stove instead of building a RMH:

My current residence is temporary. I may be here for one more year or two more. I don't know.

I cannot have a chimney visible from the street.

The pellet stove is vented below the fence line and is easily removable.

If I do try the barrel I will be certain that it is completely sealed and make provisions for cleaning.


gift
 
Unofficial Companion Guide to the Rocket Oven DVD
will be released to subscribers in: soon!
reply
    Bookmark Topic Watch Topic
  • New Topic