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Indoor rocket stove without exterior venting - is it possible?  RSS feed

 
M Sotherden
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total newbie here. Is it possible to have a rocket stove used indoors (think workshop that is used everyday) without exterior venting? Plan to get CO detector, etc, but cannot at this time vent it externally. What are the risks? I camp outdoors for an average of 6-8 wks a year, so minor smoke inhalation etc is nothing new. but would prefer not to poison myself
Thanks
MSotherden
 
Len Ovens
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M Sotherden wrote:total newbie here. Is it possible to have a Rocket stove used indoors (think workshop that is used everyday) without exterior venting? Plan to get CO detector, etc, but cannot at this time vent it externally. What are the risks? I camp outdoors for an average of 6-8 wks a year, so minor smoke inhalation etc is nothing new. but would prefer not to poison myself


I wouldn't do it. CO and particulates are not the only problem (minimum as they are in an RMH they are still there and CO is cumulative). You will need incoming oxygen and you need to remember you can't do much breathing CO2 either (and you generate a lot of CO2). So considering you need to have some place for oxygen to enter... run a pipe out the same for exhaust. Even a door open a bit... use some aluminium drier ducting, the exhaust should be cool enough by that point anyway. When you close the door just kick it back inside. The majority of the heat coming from the heater is radiant, you are not heating the air really, just so long as your back can "see" the heater you will feel warm. The other reason to exhaust is water content, if you exhaust inside, everything will be wet all the time.... just check out an rv with a propane stove when it's cool. The general thing is Oxygen and Carbohydrates in and CO2 and H2O out. You don't have to have a permanent exhaust set up, but use something.
 
ronie dee
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M Sotherden wrote:total newbie here. Is it possible to have a Rocket stove used indoors (think workshop that is used everyday) without exterior venting? Plan to get CO detector, etc, but cannot at this time vent it externally. What are the risks? I camp outdoors for an average of 6-8 wks a year, so minor smoke inhalation etc is nothing new. but would prefer not to poison myself
Thanks
MSotherden


Dearest Permifriends,

Carbon Dioxide (CO2) is not a poison to animals. It WILL KILL you however by excluding Oxygen (O2) from you. A CO detector is a Carbon Monoxide detector and will not tell you if CO2 is present.

If you burn any hydrocarbon fuel in an enclosed area you need to exhaust it outside. As your room fills with CO2 the air in the room will be forced up and the CO2 is heavier and will fill the room from the bottom up.

You will need to heat with electric or solar if you can't exhaust hydrocarbon burn to the outside of your enclosed space.
 
Hans Quistorff
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For a roof exhaust why not continue the mass to the ceiling? In northern Maine one family I called on built an octagon log cabin with a river rock mass fire place in the center. The top of the rock mass made the center ring for holding the rafters. All of the heat radiating from the mass was then in the living space instead of being exposed to the outside as in a fireplace through an outside wall.
 
M Sotherden
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Thank you to all guys/gals!

Not worried about venting the water - really - not enough humidity is actually an issue where I live during the winter months, and we already run a humidifier 24/7... so unless its a LOT of water, that doesn't concern me a bit. I didn't realise that the outgoing temp would be cool enough to use a metal dryer tube/hose/vent... and yes, that will work fine actually because that would be "normal" to have coming out of this structure (or worst case scenario, shoved out the back window wrapped in some insulation so that the window isn't leaking a ton of 20 degree air back into the area I'm trying to heat.

Thank you folks so much!

MSotherden
 
Len Ovens
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M Sotherden wrote:Thank you to all guys/gals!

Not worried about venting the water - really - not enough humidity is actually an issue where I live during the winter months, and we already run a humidifier 24/7... so unless its a LOT of water, that doesn't concern me a bit.


Think of about 10lb of water for every 10lbs of wood burned.... an imperial gallon. But the CO2 is much higher it would be higher than by weight than the wood put in (who knew air was so heavy).

Wood is a hydrocarbon. There is about twice as many hydrogen atoms as carbon, but carbon weighs 12 times as much. Oxygen weighs 16 times as much a hydrogen. So for an amount of wood (100%) the hydrogen would be about 15% (1/7) The oxygen added to that would be 8x more (2 H per O) or 135% all together. The Carbon from the same weight of wood would use twice as much oxygen (240%) plus the 85% Carbon... so the CO2 generated by any given amount of wood would weigh more than 3 times as much. Considering only about 22% of the air is oxygen to begin with and that the CO2 takes it's place... how long would it take for the oxygen level to get below breathable? (or for the fire to starve itself?)


I didn't realise that the outgoing temp would be cool enough to use a metal dryer tube/hose/vent... and yes, that will work fine actually because that would be "normal" to have coming out of this structure (or worst case scenario, shoved out the back window wrapped in some insulation so that the window isn't leaking a ton of 20 degree air back into the area I'm trying to heat.


I wouldn't worry too much about sealing the exhaust. You must have incoming air.... at least as much as the exhaust going out, but probably a lot more (you do want to breath). You are not trying to heat the air anyway. You are trying to heat you and your tools and the materials you are working on. You do not want a sealed building or anything close to it. A cardboard reflector (covered with foil?) over your work area to reflect the radiant heat from your heater to what you are working on may help though.

Keeping the fingers warm will be the hardest part. The body is a system and tries to be self regulating. If your core is warm enough, your body will start to use your extremities (like fingers) to cool your blood off. After about 45min. your fingers will be fine if your core is a little over warm. I use old sock cuffs to cover my wrists and the back of my hand (so my fingers still work) leaving a palms bare to put my fingers against when not in use. This works much better than any gloves I have tried ( I work outside, so I have tried lots). After about 45 min. my fingers no longer feel cold. Whatever material you are handling will of course effect your fingers too.

One more time, you do want air holes in your building.... You do not want a sealed building. For health, you should expect to wear warm clothes in layers so you can keep your core at the right temperature. You do want your body and the things you are working on line of sight to your heater so they can be warmed primarily by radiation. Walls are best treated to reflect radiation back inside.
 
brian hall
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my only thought would be to design it so that your exhaust gasses are relativity cool and use an inline fan to vent it out a window. say take a 2x8 and cut a 6" hole that can sit in the window frame and let you shut the window down onto it. paint it to match the exterior and no one will probably ever notice might even look like a portable dryer venting from a window.

the inline fan should negate the need for a vertical stack to make the system flow.
 
There's a way to do it better - find it. -Edison. A better tiny ad:
2017 Rocket Mass Heater Workshop Jamboree - 15 workshops in one event
https://permies.com/wiki/63312/permaculture-projects/Rocket-Mass-Heater-Workshop-Jamboree
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