High efficiency, low pollution DIY wood stove

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High efficiency, low pollution DIY wood stove
by DDHv » Thu May 12, 2016 10:26 am
DDHv Captain of the List Posts: 494 Joined: Thu Sep 11, 2014 5:59 pm	Browsing this morning, I found: http://www.richsoil.com/rocket-stove-mass-heater.jsp This is a wood stove design 1)simple enough for DIY, 2) very low pollution, and 3)very efficient. Even someone who isn't interested in building it might find the design features interesting Douglas Hvistendahl Retired technical nerd Dumb mistakes are very irritating. Smart mistakes go on forever Unless you test your assumptions!
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by DDHv » Thu May 12, 2016 10:26 am

DDHv
Captain of the List

Posts: 494
Joined: Thu Sep 11, 2014 5:59 pm

Browsing this morning, I found:

http://www.richsoil.com/rocket-stove-mass-heater.jsp

This is a wood stove design 1)simple enough for DIY, 2) very low pollution, and 3)very efficient. Even someone who isn't interested in building it might find the design features interesting

Douglas Hvistendahl
Retired technical nerd

Dumb mistakes are very irritating.
Smart mistakes go on forever
Unless you test your assumptions!

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Very Interesting ...
by HB of CJ » Thu May 12, 2016 12:05 pm
HB of CJ Captain of the List Posts: 707 Joined: Thu Jul 11, 2013 10:46 pm Location: 43N, 123W Kinda	Having heated with wood for over 20 years, (and all the dinky and other proud scars on the hands and fore arms to prove it) this new stove design is very intriguing indeed. Right now I am knee jerk reacting to the educated notion that the lateral "bumm warming seat" would overwhelm the vertical convection forces. Otherwise, the thing would "thuff". "Thuffing" being the word us wood burners understand. The conventional wood stove sometimes runs backwards and "thuffs" for a better word as smoke bellows out of the wood stove. YIKES! Not good. This happens for any number of reasons. Our vertical stove pipe is extra tall to create more of a positive draft. Even then non proper stove operations do happen. "CHUFF!" Smoky. I do not think the thing would work. Not as designed. Some sort of assist would be required to move the hot end gases sideways. Perhaps a big vertical pipe on the house outsides? Humm.
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Very Interesting ...

by HB of CJ » Thu May 12, 2016 12:05 pm

HB of CJ
Captain of the List

Posts: 707
Joined: Thu Jul 11, 2013 10:46 pm
Location: 43N, 123W Kinda

Having heated with wood for over 20 years, (and all the dinky and other proud scars on the hands and fore arms to prove it) this new stove design is very intriguing indeed.

Right now I am knee jerk reacting to the educated notion that the lateral "bumm warming seat" would overwhelm the vertical convection forces. Otherwise, the thing would "thuff".

"Thuffing" being the word us wood burners understand. The conventional wood stove sometimes runs backwards and "thuffs" for a better word as smoke bellows out of the wood stove. YIKES!

Not good. This happens for any number of reasons. Our vertical stove pipe is extra tall to create more of a positive draft. Even then non proper stove operations do happen. "CHUFF!" Smoky.

I do not think the thing would work. Not as designed. Some sort of assist would be required to move the hot end gases sideways. Perhaps a big vertical pipe on the house outsides? Humm.

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Re: High efficiency, low pollution DIY wood stove
by Joat42 » Thu May 12, 2016 3:19 pm
Joat42 Admiral Posts: 2148 Joined: Tue Apr 16, 2013 7:01 am Location: Sweden	All stoves that are directly attached to a simple vertical stove-pipe/chimney are never efficient, a lot of the heat just vents through it. In Scandinavia a lot of older houses has tiled stoves which are somewhat similar in design to the rocket stove but they don't have horizontal hypocausts and probably depending on construction doesn't have as much mass for heat retention and they still rely on a chimney that needs heating up so you get enough draft to have an efficient fire going. You can find info here about tiled stoves (aka kakelugn in Swedish). Also, the Swedish army used a portable tent stove that used the same basic principle of having the wood burn at the bottom by partitioning the stove, ie. on one side you top-fed the wood and the partition forces it to burn at the bottom into the next chamber (which gets HOT, we used to put bread slices on a fork and toast them above it) which has a small bleeder valve in the bottom so you could feed it some extra oxygen for very efficient use of the wood. Of course, these stoves only had a simple stove pipe attached (which also acts as the central support) but keeping a 20+ man tent toasty at -20C/-4F was no problem at all (although, if you are staying at the same spot for more than one night you need to dig down through the snow until you reach dirt otherwise everything will start slumping towards the stove which melts the snow under it. This can be bad since if it goes far enough the tent will collapse and you have a stove spilling embers all over your sleeping arrangements while you are battling the tent fabric to get out. Knife IS mandatory). --- Jack of all trades and destructive tinkerer. Anyone who have simple solutions for complex problems is a fool.
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Re: High efficiency, low pollution DIY wood stove

by Joat42 » Thu May 12, 2016 3:19 pm

Joat42
Admiral

Posts: 2148
Joined: Tue Apr 16, 2013 7:01 am
Location: Sweden

All stoves that are directly attached to a simple vertical stove-pipe/chimney are never efficient, a lot of the heat just vents through it.

In Scandinavia a lot of older houses has tiled stoves which are somewhat similar in design to the rocket stove but they don't have horizontal hypocausts and probably depending on construction doesn't have as much mass for heat retention and they still rely on a chimney that needs heating up so you get enough draft to have an efficient fire going.

You can find info here about tiled stoves (aka kakelugn in Swedish).

Also, the Swedish army used a portable tent stove that used the same basic principle of having the wood burn at the bottom by partitioning the stove, ie. on one side you top-fed the wood and the partition forces it to burn at the bottom into the next chamber (which gets HOT, we used to put bread slices on a fork and toast them above it) which has a small bleeder valve in the bottom so you could feed it some extra oxygen for very efficient use of the wood. Of course, these stoves only had a simple stove pipe attached (which also acts as the central support) but keeping a 20+ man tent toasty at -20C/-4F was no problem at all (although, if you are staying at the same spot for more than one night you need to dig down through the snow until you reach dirt otherwise everything will start slumping towards the stove which melts the snow under it. This can be bad since if it goes far enough the tent will collapse and you have a stove spilling embers all over your sleeping arrangements while you are battling the tent fabric to get out. Knife IS mandatory).

---
Jack of all trades and destructive tinkerer.

Anyone who have simple solutions for complex problems is a fool.

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Re: High efficiency, low pollution DIY wood stove
by Relax » Thu May 12, 2016 8:24 pm
Relax Fleet Admiral Posts: 3106 Joined: Tue Oct 27, 2009 7:18 pm	That is a crap design. If you do not have a double chamber burning stove it is not efficient as it sends its heat and partially burned fuel UP and OUT the chimney, OR, said non burned particles condense in the chimney and form creosolte which 1) smells, 2) clogs the chimney, and 3) eventually results in a chimney fire. Oh yes, and no 2nd burn chamber = smoke particulate which neither you nor your neighbors will enjoy breathing, hacking, and coughing through. By 2nd burn chamber, I mean forced air which ADDS oxygen. If a wood stove claims a 2nd burn chamber but does not ADD air, to the mixture, it is NOT a 2nd burn chamber wood stove and will have all the same problems a single chamber wood stove will have but not quite as badly. If you do no have a water jacket on a wood stove, you likewise are wasting a ton of heat as you cannot put the heat where you want(hot water and storage for when the fire is not burning) If you have a large hot water tank at 185F+ then you can wash laundry, heat the home, use to dry clothes in a clothes dryer and use as radiant heating which means you keep your rooms at lower temperature as they are warmer due to the radiation and you save even more on your heating bills. You should be able to place your hand over the exhaust vent, or nearly so depending on how quickly the wood is burning which depends on type and size of the split wood. Though a fancy double chamber stove will self regulate via how fast a fan blows the air through. Almost all so called "2 chamber" wood stoves are NOT viable options. They are merely "meh..." Here is a real wood stove: https://www.google.com/search?q=Double+ ... 85mqEBM%3A _________ Tally Ho! Relax
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Re: High efficiency, low pollution DIY wood stove

by Relax » Thu May 12, 2016 8:24 pm

Relax
Fleet Admiral

Posts: 3106
Joined: Tue Oct 27, 2009 7:18 pm

That is a crap design.

If you do not have a double chamber burning stove it is not efficient as it sends its heat and partially burned fuel UP and OUT the chimney, OR, said non burned particles condense in the chimney and form creosolte which 1) smells, 2) clogs the chimney, and 3) eventually results in a chimney fire.

Oh yes, and no 2nd burn chamber = smoke particulate which neither you nor your neighbors will enjoy breathing, hacking, and coughing through.

By 2nd burn chamber, I mean forced air which ADDS oxygen. If a wood stove claims a 2nd burn chamber but does not ADD air, to the mixture, it is NOT a 2nd burn chamber wood stove and will have all the same problems a single chamber wood stove will have but not quite as badly.

If you do no have a water jacket on a wood stove, you likewise are wasting a ton of heat as you cannot put the heat where you want(hot water and storage for when the fire is not burning) If you have a large hot water tank at 185F+ then you can wash laundry, heat the home, use to dry clothes in a clothes dryer and use as radiant heating which means you keep your rooms at lower temperature as they are warmer due to the radiation and you save even more on your heating bills.

You should be able to place your hand over the exhaust vent, or nearly so depending on how quickly the wood is burning which depends on type and size of the split wood. Though a fancy double chamber stove will self regulate via how fast a fan blows the air through.

Almost all so called "2 chamber" wood stoves are NOT viable options. They are merely "meh..."

Here is a real wood stove:
https://www.google.com/search?q=Double+ ... 85mqEBM%3A

_________
Tally Ho!
Relax

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Re: High efficiency, low pollution DIY wood stove
by Daryl » Thu May 12, 2016 8:34 pm
Daryl Fleet Admiral Posts: 3503 Joined: Sat Apr 24, 2010 1:57 am Location: Queensland Australia	What we call slow combustion stoves use a similar principle, and have done so for nearly a century. These are largish cooking stoves with insulated sides and doors. They have a tall narrow firebox, at the top of which the exhaust goes sideways across the oven and under the hotplate. With some you can divert some of the exhaust down the side of the oven if you want it hotter. By the time the brass/copper heat exchanger heats water in the hot water system by thermos syphoning there isn't much heat left in the exhaust, which exits out a 5 inch diameter but tall metal chimney. They use much less wood and don't overheat the kitchen compared to old style cast iron stoves. Incidentally the old style brick fireplace works best if there is a dogleg at the base of the chimney.
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Re: High efficiency, low pollution DIY wood stove

by Daryl » Thu May 12, 2016 8:34 pm

Daryl
Fleet Admiral

Posts: 3503
Joined: Sat Apr 24, 2010 1:57 am
Location: Queensland Australia

What we call slow combustion stoves use a similar principle, and have done so for nearly a century.
These are largish cooking stoves with insulated sides and doors.
They have a tall narrow firebox, at the top of which the exhaust goes sideways across the oven and under the hotplate. With some you can divert some of the exhaust down the side of the oven if you want it hotter.
By the time the brass/copper heat exchanger heats water in the hot water system by thermos syphoning there isn't much heat left in the exhaust, which exits out a 5 inch diameter but tall metal chimney.
They use much less wood and don't overheat the kitchen compared to old style cast iron stoves.

Incidentally the old style brick fireplace works best if there is a dogleg at the base of the chimney.

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Re: High efficiency, low pollution DIY wood stove
by DDHv » Fri May 13, 2016 8:47 pm
DDHv Captain of the List Posts: 494 Joined: Thu Sep 11, 2014 5:59 pm	I see your reasons. 1) Why do you say there is no second chamber? 2) Mod. One design uses a plate to force a gap for extra air through the fuel feed chamber and into the burn tunnel. There is mention of burning the smoke in the hypocaust and riser. The site states that temperature at the bottom of the riser can reach around 2,000 degF once fully operating. The difference in temperature between this riser updraft and the outer vertical downdraft provide the net draft. For it to work, close attention would be needed to keep friction losses low to prevent choking since the amount of net draft is limited. The hypocaust would need to be the primary choke. 3) Consider that the site mentions: These are both the products of the leaders in rocket mass heater innovation, Ernie and Erica Wisner, who have built more than 700 rocket mass heaters. Your points on heat storage and distribution make a lot of sense. The best design would have the water coils in the down draft section to further cool it. Also, they state that the final exhaust temperature is "only a little" above room temperature, whatever they mean by that. Personally, I'm going to price fireclay, etc. It should be simple to build and test one outside to see how well it works. It can then be taken apart and rebuilt inside. My 40 foot chimney tends to have too much draft, once it gets going, and not enough when starting. A damper controls this at the cost of bringing more cold air into the house. They state that only when starting is the induced draft low enough to allow smoke to return. (thuffing) They suggest keeping the hypocaust area relatively small to have high air velocity there. A quick look at the plans shows a hypocaust area of about half the area elsewhere. Properly designed, this would mean that almost all of the friction losses would be concentrated there PS, another example of excellent design on a totally different subject can be found by searching on "Warka water tower" Last edited by DDHv on Wed Jun 29, 2016 8:25 pm, edited 2 times in total. Douglas Hvistendahl Retired technical nerd Dumb mistakes are very irritating. Smart mistakes go on forever Unless you test your assumptions!
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Re: High efficiency, low pollution DIY wood stove

by DDHv » Fri May 13, 2016 8:47 pm

DDHv
Captain of the List

Posts: 494
Joined: Thu Sep 11, 2014 5:59 pm

I see your reasons.

1) Why do you say there is no second chamber?

2) Mod. One design uses a plate to force a gap for extra air through the fuel feed chamber and into the burn tunnel. There is mention of burning the smoke in the hypocaust and riser. The site states that temperature at the bottom of the riser can reach around 2,000 degF once fully operating. The difference in temperature between this riser updraft and the outer vertical downdraft provide the net draft. For it to work, close attention would be needed to keep friction losses low to prevent choking since the amount of net draft is limited. The hypocaust would need to be the primary choke.

3) Consider that the site mentions:

These are both the products of the leaders in rocket mass heater innovation, Ernie and Erica Wisner, who have built more than 700 rocket mass heaters.

Your points on heat storage and distribution make a lot of sense. The best design would have the water coils in the down draft section to further cool it. Also, they state that the final exhaust temperature is "only a little" above room temperature, whatever they mean by that.

Personally, I'm going to price fireclay, etc. It should be simple to build and test one outside to see how well it works. It can then be taken apart and rebuilt inside. My 40 foot chimney tends to have too much draft, once it gets going, and not enough when starting. A damper controls this at the cost of bringing more cold air into the house.

They state that only when starting is the induced draft low enough to allow smoke to return. (thuffing) They suggest keeping the hypocaust area relatively small to have high air velocity there. A quick look at the plans shows a hypocaust area of about half the area elsewhere. Properly designed, this would mean that almost all of the friction losses would be concentrated there
:!:

PS, another example of excellent design on a totally different subject can be found by searching on "Warka water tower"
:idea:

Last edited by DDHv on Wed Jun 29, 2016 8:25 pm, edited 2 times in total.

Douglas Hvistendahl
Retired technical nerd

Dumb mistakes are very irritating.
Smart mistakes go on forever
Unless you test your assumptions!

Top

Re: High efficiency, low pollution DIY wood stove
by Relax » Mon May 16, 2016 1:27 am
Relax Fleet Admiral Posts: 3106 Joined: Tue Oct 27, 2009 7:18 pm	You have to answer the question of: What is Creosote What is smoke Answer: Unburned fuel. The other giant give away was the fact that the Swedish design has to be rebuilt every few years. Well yea, it does, the dumb thing is impossible to clean and it chokes itself to death via unburned fuel that coats its inside surfaces. Anyone can make a chimney from a fire come out cold, of course you have to clean the chimney all the time as massive amounts of creosote is created via cutting off the oxygen. That in no way is efficient, OTHER THAN, the fact that the fire burns lower for a longer period of time which, uh hem, which corellates to a more even heat output without a giant spike which is actually a more efficient burn. The only way to burn all that fuel that is not being burned, is to add extra oxygen AND burn it at higher temperature SO, the fuel combusts instead of either going UP and OUT the chimney or coating the inside of the chimney. If the chimney output is CLEAR and COLD, then you have high efficiency. If you do not have either, then you do not have high efficiency. _________ Tally Ho! Relax
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Re: High efficiency, low pollution DIY wood stove

by Relax » Mon May 16, 2016 1:27 am

Relax
Fleet Admiral

Posts: 3106
Joined: Tue Oct 27, 2009 7:18 pm

You have to answer the question of:
What is Creosote
What is smoke

Answer: Unburned fuel.

The other giant give away was the fact that the Swedish design has to be rebuilt every few years. Well yea, it does, the dumb thing is impossible to clean and it chokes itself to death via unburned fuel that coats its inside surfaces.

Anyone can make a chimney from a fire come out cold, of course you have to clean the chimney all the time as massive amounts of creosote is created via cutting off the oxygen. That in no way is efficient, OTHER THAN, the fact that the fire burns lower for a longer period of time which, uh hem, which corellates to a more even heat output without a giant spike which is actually a more efficient burn.

The only way to burn all that fuel that is not being burned, is to add extra oxygen AND burn it at higher temperature SO, the fuel combusts instead of either going UP and OUT the chimney or coating the inside of the chimney.

If the chimney output is CLEAR and COLD, then you have high efficiency. If you do not have either, then you do not have high efficiency.

_________
Tally Ho!
Relax

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Re: High efficiency, low pollution DIY wood stove
by DDHv » Mon May 16, 2016 7:28 pm
DDHv Captain of the List Posts: 494 Joined: Thu Sep 11, 2014 5:59 pm	Relax wrote:You have to answer the question of: What is Creosote What is smoke Answer: Unburned fuel. The other giant give away was the fact that the Swedish design has to be rebuilt every few years. Well yea, it does, the dumb thing is impossible to clean and it chokes itself to death via unburned fuel that coats its inside surfaces. Anyone can make a chimney from a fire come out cold, of course you have to clean the chimney all the time as massive amounts of creosote is created via cutting off the oxygen. That in no way is efficient, OTHER THAN, the fact that the fire burns lower for a longer period of time which, uh hem, which corellates to a more even heat output without a giant spike which is actually a more efficient burn. The only way to burn all that fuel that is not being burned, is to add extra oxygen AND burn it at higher temperature SO, the fuel combusts instead of either going UP and OUT the chimney or coating the inside of the chimney. If the chimney output is CLEAR and COLD, then you have high efficiency. If you do not have either, then you do not have high efficiency. Exactly correct. The thing I like best about this particular design is that it burns the unburned fuel immediately after the primary burn. There is a reason they call the hypocaust the burn tunnel. You may recall the part where they specifically emphasize the importance of turbulence in the burn tunnel in order to completely mix the unburned fuel with the extra air. FWIR, the exit end of the burn tunnel gets yellow hot - stainless was tried for the updraft heat riser, but it couldn't stand the heat for long. Only ceramics can handle temperatures that can reach 2500 degF on occasion. Following the burn tunnel it uses the insulated updraft heat riser and downdraft heat loser (barrel) temperature difference to produce the draft. The gasses exiting the barrel tend to be below 600 degF. Only after the barrel has lost heat to the room does the final mass heat exchanging cool the exhaust the rest of the way to about 150 degF. Given the limited draft, large passages, except for the burn tunnel, are likely needed. I can't speak to the Swedish design, but We used this heater for about 3 years on site. We cleaned out the fly ash about once per year, an accumulation of several inches in the bottom of the barrel. We also noticed benefits in summer heat waves: we didn't need to get the fans out of the attic for summer cooling. Of course, in summer there won't't be any burning The original was made in Portland Oregon as an experimental design, and their standards are high. My primary objection is the amount of labor involved, but being retired, some of my time is available. It looks as bad as a built-in-place fireplace - or worse. Speaking of local jurisdictions: Our woodstove inspectors didn't know what to make of our project. The City of Portland's Alternative Technologies Advisory Committee has since approved a draft building code for rocket mass heaters, with a 1-week pre-installation approval process; this plan should pass with one substitution: firebrick in combustion areas. Given the peak temperatures in the afterburner sections (burn tunnel and updraft riser) I would certainly insist on using high temperature ceramic there PS You can get a PDF set of plans and maintenance manual for free if you subscribe to the permaculture Richsoil email. Go to where I stumbled on it: http://www.richsoil.com/rocket-stove-mass-heater.jsp Douglas Hvistendahl Retired technical nerd Dumb mistakes are very irritating. Smart mistakes go on forever Unless you test your assumptions!
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Re: High efficiency, low pollution DIY wood stove

by DDHv » Mon May 16, 2016 7:28 pm

DDHv
Captain of the List

Posts: 494
Joined: Thu Sep 11, 2014 5:59 pm

Relax wrote:You have to answer the question of:
What is Creosote
What is smoke

Answer: Unburned fuel.

The other giant give away was the fact that the Swedish design has to be rebuilt every few years. Well yea, it does, the dumb thing is impossible to clean and it chokes itself to death via unburned fuel that coats its inside surfaces.

Anyone can make a chimney from a fire come out cold, of course you have to clean the chimney all the time as massive amounts of creosote is created via cutting off the oxygen. That in no way is efficient, OTHER THAN, the fact that the fire burns lower for a longer period of time which, uh hem, which corellates to a more even heat output without a giant spike which is actually a more efficient burn.

The only way to burn all that fuel that is not being burned, is to add extra oxygen AND burn it at higher temperature SO, the fuel combusts instead of either going UP and OUT the chimney or coating the inside of the chimney.

If the chimney output is CLEAR and COLD, then you have high efficiency. If you do not have either, then you do not have high efficiency.

Exactly correct. The thing I like best about this particular design is that it burns the unburned fuel immediately after the primary burn. There is a reason they call the hypocaust the burn tunnel. You may recall the part where they specifically emphasize the importance of turbulence in the burn tunnel in order to completely mix the unburned fuel with the extra air. FWIR, the exit end of the burn tunnel gets yellow hot - stainless was tried for the updraft heat riser, but it couldn't stand the heat for long. Only ceramics can handle temperatures that can reach 2500 degF on occasion.

Following the burn tunnel it uses the insulated updraft heat riser and downdraft heat loser (barrel) temperature difference to produce the draft. The gasses exiting the barrel tend to be below 600 degF. Only after the barrel has lost heat to the room does the final mass heat exchanging cool the exhaust the rest of the way to about 150 degF. Given the limited draft, large passages, except for the burn tunnel, are likely needed.

I can't speak to the Swedish design, but

We used this heater for about 3 years on site. We cleaned out the fly ash about once per year, an accumulation of several inches in the bottom of the barrel. We also noticed benefits in summer heat waves: we didn't need to get the fans out of the attic for summer cooling.

Of course, in summer there won't't be any burning

The original was made in Portland Oregon as an experimental design, and their standards are high. My primary objection is the amount of labor involved, but being retired, some of my time is available. It looks as bad as a built-in-place fireplace - or worse.

Speaking of local jurisdictions: Our
woodstove inspectors didn't know what to make of our project. The City of Portland's Alternative Technologies Advisory Committee has since approved a draft building code for rocket mass heaters, with a 1-week pre-installation approval process; this plan should pass with one substitution: firebrick in combustion areas.

Given the peak temperatures in the afterburner sections (burn tunnel and updraft riser) I would certainly insist on using high temperature ceramic there :!:

PS You can get a PDF set of plans and maintenance manual for free if you subscribe to the permaculture Richsoil email. Go to where I stumbled on it:

http://www.richsoil.com/rocket-stove-mass-heater.jsp
:idea:

Douglas Hvistendahl
Retired technical nerd

Dumb mistakes are very irritating.
Smart mistakes go on forever
Unless you test your assumptions!

Top

Re: High efficiency, low pollution DIY wood stove
by DDHv » Mon Jun 27, 2016 9:20 am
DDHv Captain of the List Posts: 494 Joined: Thu Sep 11, 2014 5:59 pm	In following up on RSMHs a commercial source of UL listed and well designed Rocket Stoves was located. http://www.rocketheater.com/ The rocket stove mass heater has two sources of efficiency. The Rocket stove part produces very high burn efficiency by burning up the smoke and creosote once it has reached operating temperatures. The mass heater part acts like a Russian furnace by absorbing the exhaust's heat and releasing it gradually. The rocket stove part is now commercially available. Adding a mass heater part would still be locally produced - it would make an interesting DYI project. They spent a lot on the engineering and getting the UL listing. They estimate they can spend a year trying it as a business. Whether their micro-factory will be around thereafter will depend on order quantity. Since this by itself is much more efficient and less polluting than any standard design wood stove, it should be looked at even by those not interested in the mass heater. These are entrepreneurs with a good product that can save cash for anyone able to use wood heat. Above all, window shopping doesn't cost anything Douglas Hvistendahl Retired technical nerd Dumb mistakes are very irritating. Smart mistakes go on forever Unless you test your assumptions!
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Re: High efficiency, low pollution DIY wood stove

by DDHv » Mon Jun 27, 2016 9:20 am

DDHv
Captain of the List

Posts: 494
Joined: Thu Sep 11, 2014 5:59 pm

In following up on RSMHs a commercial source of UL listed and well designed Rocket Stoves was located.

http://www.rocketheater.com/

The rocket stove mass heater has two sources of efficiency. The Rocket stove part produces very high burn efficiency by burning up the smoke and creosote once it has reached operating temperatures. The mass heater part acts like a Russian furnace by absorbing the exhaust's heat and releasing it gradually. The rocket stove part is now commercially available. Adding a mass heater part would still be locally produced - it would make an interesting DYI project.

They spent a lot on the engineering and getting the UL listing. They estimate they can spend a year trying it as a business. Whether their micro-factory will be around thereafter will depend on order quantity. Since this by itself is much more efficient and less polluting than any standard design wood stove, it should be looked at even by those not interested in the mass heater.
:!:

These are entrepreneurs with a good product that can save cash for anyone able to use wood heat. Above all, window shopping doesn't cost anything

Douglas Hvistendahl
Retired technical nerd

Dumb mistakes are very irritating.
Smart mistakes go on forever
Unless you test your assumptions!

Top

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