Ember Hearth stove

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Ember Hearth

Member
Nov 28, 2018
12
U.S.A.
Well to close the loop on this question from Nov. 2018, I got the stove installed after doing some upgrades to make my "boat anchor" a bit better. For one thing, I replaced all of the gaskets around the door, welded up an external air source that is fan-driven from my solar power system, and installed the chimney through the concrete wall in a manner very similar to the diagram shown in my post two times ago.

The stove draws very well with no back draft, in part due to the forced air outside source and the air-tight nature of the stove itself.

The stove's firebox is surrounded by a plenum that is fan-driven so that I can distribute heat from the firebox very efficiently. A solar powered squirrel cage fan can be switched on and off as desired to increase the heat distribution.

Single wall stove pipe goes up to the concrete wall, and then converts to double wall stainless steel pipe that penetrates the concrete, goes 8 feet horizontally into a "T" and then vertical. A triad of stainless steel cables support the chimney pipe on the outside and the base is supported by the "T" which is connected to base rock with rebar and concrete. Clean out is from the inside "T" out to the external "T" which has a capped bottom opening. Vertical cleaning is by way of the external "T" and up. The vertical pipe can be easily removed in 6 foot sections for cleaning as well.

This stove is for emergency no-power use. Normally my geothermal HVAC system will be used for heating and cooling, but in an extreme emergency, my "boat anchor" is there to heat the underground basement living area. A short stack is used now, but for extended use, 18 feet of additional double-wall stainless steel pipe can easily be added to extend the chimney. As mentioned in my initial post, I designed my house out of steel (no wood construction). It has fiber-concrete Nichiha siding, fireproof sub flooring, 5/8 fire rock everywhere, and the basement is poured concrete, so the 10-3-2 rule doesn't apply according to my local inspector. The forced outside air seems to take care of chimney drawing issues even when all of the pipe sections are not in place.

The attached pictures show the single wall stove pipe going up to the through-the-wall double wall pipe transition. The next picture shows the stove with a good fire, and the third picture is the external solar powered (solar during the day, battery backup at night) forced air source to conserve heated room air and to force the draft.
 

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clancey

Minister of Fire
Feb 26, 2021
1,421
Colorado
In my estimation you seem to be very talented and smart and prepared.. That thing would work as a boat anchor--enjoyed...clancey
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,667
central pa
Well to close the loop on this question from Nov. 2018, I got the stove installed after doing some upgrades to make my "boat anchor" a bit better. For one thing, I replaced all of the gaskets around the door, welded up an external air source that is fan-driven from my solar power system, and installed the chimney through the concrete wall in a manner very similar to the diagram shown in my post two times ago.

The stove draws very well with no back draft, in part due to the forced air outside source and the air-tight nature of the stove itself.

The stove's firebox is surrounded by a plenum that is fan-driven so that I can distribute heat from the firebox very efficiently. A solar powered squirrel cage fan can be switched on and off as desired to increase the heat distribution.

Single wall stove pipe goes up to the concrete wall, and then converts to double wall stainless steel pipe that penetrates the concrete, goes 8 feet horizontally into a "T" and then vertical. A triad of stainless steel cables support the chimney pipe on the outside and the base is supported by the "T" which is connected to base rock with rebar and concrete. Clean out is from the inside "T" out to the external "T" which has a capped bottom opening. Vertical cleaning is by way of the external "T" and up. The vertical pipe can be easily removed in 6 foot sections for cleaning as well.

This stove is for emergency no-power use. Normally my geothermal HVAC system will be used for heating and cooling, but in an extreme emergency, my "boat anchor" is there to heat the underground basement living area. A short stack is used now, but for extended use, 18 feet of additional double-wall stainless steel pipe can easily be added to extend the chimney. As mentioned in my initial post, I designed my house out of steel (no wood construction). It has fiber-concrete Nichiha siding, fireproof sub flooring, 5/8 fire rock everywhere, and the basement is poured concrete, so the 10-3-2 rule doesn't apply according to my local inspector. The forced outside air seems to take care of chimney drawing issues even when all of the pipe sections are not in place.

The attached pictures show the single wall stove pipe going up to the through-the-wall double wall pipe transition. The next picture shows the stove with a good fire, and the third picture is the external solar powered (solar during the day, battery backup at night) forced air source to conserve heated room air and to force the draft.
Forced induction on a woodstove can create extreme temps both in the stove and out the chimney. I would be extremely careful and monitor temps closely. I have seen similar things tried at best they wasted lots of heat up the chimney at worst the melted the stove. Pressurizing the stove can also lead to co leakage as the fire burns down.
 

Ember Hearth

Member
Nov 28, 2018
12
U.S.A.
Forced induction on a woodstove can create extreme temps both in the stove and out the chimney. I would be extremely careful and monitor temps closely. I have seen similar things tried at best they wasted lots of heat up the chimney at worst the melted the stove. Pressurizing the stove can also lead to co leakage as the fire burns down.
Temperature is monitored with multiple set-point alarming thermometers and the external air flow is adjustable. Were the temperature to even approach 2000°F, alarms would sound. The melting point of the lowest temperature components in the system (430 Stainless Steel double-wall chimney pipe) is 2597 °F. A creosote chimney fire can reach up to 2000°F, but that won't melt the stove. (I’ve got both CO2 and dry siliconized monoamonium phosphate powder fire extinguishers in the room with the stove). If conditions are right (wind direction/Bernoulli effect at the chimney cap) and inside/outside pressure differential, the external air will be drawn into the firebox even without use of the forced air fan. As the fire subsides, CO will be expelled out the wide (8-inch) chimney pipe in far greater volume compared to that leaking through the door seals. Nonetheless, a CO monitor on the wall in the basement will alert in the presence of excess carbon monoxide.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
25,667
central pa
Temperature is monitored with multiple set-point alarming thermometers and the external air flow is adjustable. Were the temperature to even approach 2000°F, alarms would sound. The melting point of the lowest temperature components in the system (430 Stainless Steel double-wall chimney pipe) is 2597 °F. A creosote chimney fire can reach up to 2000°F, but that won't melt the stove. (I’ve got both CO2 and dry siliconized monoamonium phosphate powder fire extinguishers in the room with the stove). If conditions are right (wind direction/Bernoulli effect at the chimney cap) and inside/outside pressure differential, the external air will be drawn into the firebox even without use of the forced air fan. As the fire subsides, CO will be expelled out the wide (8-inch) chimney pipe in far greater volume compared to that leaking through the door seals. Nonetheless, a CO monitor on the wall in the basement will alert in the presence of excess carbon monoxide.
Your chimney is rated to 1000 degrees continuous. It is only rated to handle 2100 for ten ten minute periods. And stoves can get warped and damaged if run over 1000 for very long or very often.

As far as co yes it will get pushed out the chimney unless it doesn't. I am just pointing out the potential dangers associated with setups like this
 

Ember Hearth

Member
Nov 28, 2018
12
U.S.A.
Your chimney is rated to 1000 degrees continuous. It is only rated to handle 2100 for ten ten minute periods. And stoves can get warped and damaged if run over 1000 for very long or very often.

As far as co yes it will get pushed out the chimney unless it doesn't. I am just pointing out the potential dangers associated with setups like this
No, I appreciate your comments. I shall set the thermometer alarms for just over 1000°F based on your comment. The intent is that were the temperature to take off, I would throttle it back quickly. This stove would NEVER be allowed to run unattended (i.e., with no one at home or not within ear-shot of the alarms).

I have drone footage of the house on top of the mountain behind my home (about ½ mile away). It burnt to the ground (in spite of the fire department showing up) after the owner turned on his wood-burning stove and then walking away to go fishing with a friend. Something happened (chimney fire?) and he lost his whole house in the space of about 45 minutes.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
25,667
central pa
No, I appreciate your comments. I shall set the thermometer alarms for just over 1000°F based on your comment. The intent is that were the temperature to take off, I would throttle it back quickly. This stove would NEVER be allowed to run unattended (i.e., with no one at home or not within ear-shot of the alarms).
I would set the alarms at 900. Is the pipe temp measurement surface or internal measurement? If it is surface it should be at 500