Podcast question

Hi there
I (half, I was busy elsewhere)listened to the most recent podcast (i think) anyway one of the things that I highlighted was Ernie's comment that you could heat a 5000square foot building with a single 8inch RMH if the building was designed correctly. Can you elaborate on what this design would look like?

Thanks Adam

I'm not sure it would look like. But here's a link to the podcast, that in turn, has links to info that might point you in the right direction:

http://www.richsoil.com/permaculture/782-podcast-104-rocket-mass-heaters-with-ernie-and-erica/

HTH

Do you want a contemporary house design or a sustainable house design? it makes very large difference.

Either, I'm thinking you would have to have a completely open plan, single floor building with the RMH in the centre of the building. Hopefully the air would be pumped around the large room by convection. It would be a bit hit and miss though. Only other way I can see is to have the RMH heat water and pump that around to distribute the heat but that has it's problems. The problem is going to be distributing the heat I think.

not really you are thinking to modern. old houses had grates from the lower floor to the upper for moving heat. louvered vents over doors to do the same.
vents in the top floor rooms to make draw.

then you have the materials the walls where made from, Plaster and lath walls may not be insulated but are usually warm to the touch. 1 inch of plaster s pretty good thermal mass.

A single open room is great for radiant heat but kinda sucks for privacy. the main room could do with an RMH but the bedrooms might do well with a little pocket rocket to take the chill off just before bed. the kitchen seldom needs heating since it is usually heated by the cooking activity.

the exhaust does not have t be run totally in cob ours is going o be in a cabinet that will use the rising warm air as a pump to heat our bedroom. a cob house needs to be heated for a time and then the walls take over most of the job re radiating heat out to the room for many hours after the fire has gone out. then you have may passive solar designs to choose from. the best IMO is the tromb wall idea, when done right it will heat the house effectively with no other input.

Erica and I teach RMH construction and fire science along with (when folks want me to) passive solar and other types of home heating. In some cases an RMH is not a good answer and i will tell clients that , some folks get upset but most understand that Erica and I do our level best for them it might not meet our exact needs but we are being employed to help the client heat the house as effectively as possible.


What i mean to say is that every house design should be looked at for all the ways to heat and cool it, no one has a magic bullet.

I don't see how the heat would distribute around a multi room building. If you had a RMH in every room that would work just fine but the goal was just the one. I wonder if a person had garden water hose/air ducts embedded just under the surface in the cob walls, that went all over the house that may conduct heat well enough without any pumps. A cob wall will retain its heat yes but if it's no where near the fire it wont get any heat in the first place.

it depends on how you design the building. how big of building is it? how many rooms? is it a big rectangle? or is it laid out like a California split level ranch?

here is the problem with simple questions, I cant assume the design of your house, how the rooms are laid out. how high the ceilings are ETC.

You on the other hand cant assume that the way a stove heats is dependent on radiant , convection or conduction. the way to get a stove to heat a whole house is to use these properties in different ways. you might need to add a ceiling fan or a common wall or put part of the exhaust duct through into another room.

if your assumption is put a big stove in the middle of a single room with no design elements to move heat around. it wont work very well.

Are we done pissing on the marking post, so we can actually get to the specific question?
I need actual data in order to give you an answer.

lol


Anyway I don't have a house yet... So the question is, in an ideal world if you where building a house from scratch and could design it anyway you wanted what would be the ideal layout?

I'm just guessing but here are some numbers I've just pulled off the top of my head
..................Length..Width..Area..Perimeter. Kitchen...........20......15.....300...70........ Bedroom...........20......20.....400...80........ Bedroom...........20......20.....400...80........ Bedroom...........20......20.....400...80........ Walk in wardrobe..15......15.....225...60........ Living room.......35......35.....1225..140....... Study.............15......15.....225...60........ Office............15......15.....225...60........ Bathroom..........15......15.....225...60........ Toilet............10......10.....100...40........ ..........................Total..3725..730.......

I'd also have a large garage, pantry, a large green house and large porch but they would all be unheated

I'd build something similar to this http://fugadeideas.org/paccs/tom/index.shtml
Little to no heating or cooling year round and easy to maintain.

ok so assume a single level house, the radial layout is the norm from the living room kitchen common wall. you don't want to heat the kitchen its going to be warm enough as soon as you start cooking.

so the best place would be to put the stove into the wall by the hall way to the bedrooms Etc. if you place it on the corner with LOS to the back of the hall you will get good heating from all the surfaces in the hall way and pretty much keep that end of the house toasty.
if you stack it by putting rooms on a second floor with floor vents you will not only heat the living room but the upper rooms as well.
if its a California ranch, give it up. not even forced air works on those things. Now if i was to design a house from scratch (As we are doing for a cob bale in Tonasket. I don't actually want to much heat in my office and i want to be able to go out whenever i want to work on something without waking everyone up.
I would go with passive solar and sliding glass doors. for Ericas office (she paints and does lots of crafts as well as drafting) I would do a glass roof and make the mass heater in one wall. and the living room, this also takes care of the other rooms as our needs are we like to sleep a bit cool.
So Erica gets not only radiant heat but conductive as well. the living room gets radiant convective and conductive. the rooms and my office gets re-radiant off the surfaces in the hallways and some convective.

Den you might notice i didn't even address, in the den i would put a rumford fireplace. the den is a space you will be using for things like entertaining meetings movies with the family Etc. I have observed in each of these that a nice open fire is far more conductive than some other heating system.

Alright thats all the time i have for this today.