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Radiant heat from a RMH in a house with many rooms  RSS feed

 
Posts: 71
Location: Tennesse, an hour west of Nashville, zone 7
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So if the heat from a RMH is primarily radiant, I would think that it would be most warm when you are in line of sight of the mass. What about other rooms that do not contain the RMH? Does it heat the air enough to warm them? Or do you pile comforters on your bed and make your potty breaks quick?
 
pollinator
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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matt hogan : The prompt or first heat that comes off of the barrel is necessary to make your rocket mass heater RMH roar, and provide the great efficiency that
is possible with high temperature gasification of the small diameter super dry wood, we feed the Rocket !

This prompt heat is ~40%~ of the total heat and Sized to the location you need to heat will definitely warm the initial space with radiant heat.

It is the other heat energy, ~60%~ that remains in the gas stream that is circulated through the Rockets Great thermal mass that is absorbed into that mass and
is slowly radiated off into the Environment that provides the warmth for a further 12 - 24 hrs AFTER the Thermal Mass is heated and the fire is Allowed to go out.

Compared to a conventional wood stove the warmth given off is at a lower temperature allowing you to snuggle right up to the mass, and will release that heat at
that temperature over a longer time period.

With ether the RMH, or a conventional wood heater heating distant rooms is equally problematic !

Please consider my strong recommendation to go to Rocketstoves.com to pick up a copy of the brand new 3r edition of Ianto Evans' great book " rocket mass heaters"

This will allow you to quickly 'come up to speed' and help you speak the same language as your fellow Rocketeers, the little bit of 'Math' that you will need to understand
is all pretty much 4th grade stuff.

Come back here often, there are lots ofFellow members here with direct hands on experience, some may be very close to you ! Big AL
 
matt hogan
Posts: 71
Location: Tennesse, an hour west of Nashville, zone 7
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Thanks. I'm planning on getting the book. I've watched the DVD's.

The difference between the wood stove and RMH is that, with the wood stove, much of the heat is convection so you can use a blower or other fan to push heat to another room. With the RMH, most of the heat is radiant and so moving the air will not move the heat, right? So it seems that getting the heat into another room is more of an issue.

Am I making sense?
 
allen lumley
pollinator
Posts: 4154
Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Matt : Just a little background, 1st came the Rocket Cookstove, very efficient at turning twigs and small wood into Heat Energy. Mostly because the type of insulation surrounding the
combustion chamber, This was developed for third world counties where 40% of The People still cook on 'three rock fires'! A vast improvement over the rocks but much of the Heat
Energy produced by our efficient burn still was lost to the environment.

The rocket mass heater, RMH burns super efficiently, ( zero creosote ) with 40% again being the prompt heat That Makes the push me - pull you magic! Think of that Lost Heat as the
work energy that allows use to flow the remaining hot exhaust gasses Up to 50' Horizontally while giving up its heat energy into the thermal mass, and the temperature of the gases
in our final Vertical Chimney, being around 140dF!

Air Is an almost perfect insulator, and is actually a damn poor material to store or transport Heat, but we have a legacy from the days of Cheap Fossil Fuels, and forced air heat, of
thinking this must be the way to go ! - We burn Fossil Fuels, or Wood, literally Frying our Air Trying to get it to hold enough heat to make us feel warm ! Without ductwork to channel
our hot air from room to room ( and don't forget a return air supply must be allowed for ) We are trying to herd cats and are grateful for any Air/Heat flow at all, preferring not to think
about the fact that our ceilings are the warmest part oft he house!

The 50' running feet of thermal mass can be made into a bed, or couch/ bench or built up to be a kitchen counter with cooking surface and/or ovens/warming areas. It can also be
configured (House shape making it practical ) into a continuous heat source and a piece of Fine Hand-crafted built-in furniture running from your primary room into a second or even
a third room!

The 1st 40% is radiant energy that travels though the air to a solid object ( hopefully you!) that object warms up and the we get some warming of the air, the Last Heat the 60% of the
Heat Energy Now stored in the Cob/Thermal Mass Warms its surroundings slowly and for a long time through conduction or direct contact, Your But to the Bench.

In retro fitting an existing house The RMH will always out perform a space heater type of un-ducted wood stove for Efficiency, smooth even heat over a longer period of time,
and in comfort when properly Built!

Generally we use ductwork within the Thermal Mass to channel our hot exhaust gases, but we do away with any need for ductwork to move air! We are trading the need to plan carefully
for the bulkiness of our built in furniture/Thermal Mass and the barrel, to totally avoid the need for air handling ductwork with its own poor efficiencies !

I hope this helps ! Read the book a couple of times, and come back here and get help on this and other projects from your nearly 25,000 Fellow Members ! Big AL !

 
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hiu matt i am a newby so may be wrong here as i have no personal experience of this,but... you could use a peltier driven fan or even 2 or 3 on top of the drum to stir up the air. plenty of youtube vids on how to make one cheaply. i live in a very damp granite house in cornwall UK so know a bit about cold. we use a desiccant dehumidifier in the winter. it really does make a big difference depending on whether you live in a damp climate or a dry cold one. draws about 300 watts or so.
 
matt hogan
Posts: 71
Location: Tennesse, an hour west of Nashville, zone 7
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Bob, thank you for your reply.

Al, thank you for your time. I am aware of the history and functionality of the RMH. I'm trying to figure out how to use it to heat other rooms with it. It is a very particular question.
 
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