I've been reading Ernie and Erica's book and watching Paul's DVDs and I'm getting ready to build my own RMH. But I have a few questions: 1- I have a cement base of 3ft by 7ft to put the heater on, no basement underneath. On the other side of the 7ft wall is a bedroom. Is there enough room to put a RMH and have enough mass. my house is approx 700 sq ft. fairly open concept.
2- We have a lot of sandstone on our property and I would like to make the heater look somewhat like a masonry heater, I understand the idea behind not covering the barrel with bricks and stone because of the air flow but I was wondering if a person built a stone wall in front of the barrel to hide the barrel and left a space between the barrel and the wall, and even left a few holes in the stone wall, especially at the bottom for air flow, would that change anything?
Hi Helene; Welcome to Permies!
We really need some more info on the layout of your house 700 sq ft should be easily doable.
What kind of chimney do you have or plan to have?
Where are you located ? How cold is it going to get ?
Are you familiar with the brick bell style of RMH? One of them could fit in the size you have avalable.
Not all who wander are lost... J.R.R. Tolkien
posted 3 months ago
Thanks guys for the replies. Yes Aaron, that is galvanized roofing on the walls that was the best I could find ;o)
Thomas, the house is in New Brunswick Canada where the weather can dip below -25C in winters, not sure where that would be in Fahrenheit, We're in the middle of a snowstorm as I'm writing this. As far as the layout of the house, the room where the stove is is about 10 x 10, so is the bedroom behind the stove wall. Across from the stove on the right of the picture is the open kitchen-living room and front entrance roughly 20 x 20. The chimney is double insulated typical chimney installed by a professional renovator. We had our first snow storm 6 weeks early in November and ran out of power for 2 days, the house wasn't finished yet so I borrowed this ancient stove from my brother's barn. it's not legal and not very efficient but better than the high electricity costs.
By "Brick bell style of RMH" are you talking about the heat riser made out of fire brick or are you saying that the bell would be built out of brick instead of an old steel drum? Is there a picture of one in Erica and Ernie's book? Or where would I find a plan for that? I was kinda hoping to use an old drum as I have a bunch of them lying around in the yard but if there's not enough room on my 3X7 cement pad....
What size is your chimney ? 6" or 8" Block or metal pipe ? Is it all indoors or outside the wall ?
-25 C is -13 F .
A standard rmh as described in the builders guide, uses a barrel as a bell, a transition area where the exhaust starts moving horizontally thru the pipes surrounded by cob and buried under large rocks. This bench is commonly used as a couch or day bed. Some folks use cob on the whole bench , some like me surrounded the cob mass with brick or other hard material to avoid repairing chipped cob off the bench, and as additional mass.
Your concrete slab is too small for this style of mass.
There are options here though. To start, we know you have no basement. What is your floor ? Wood ? Is it or can it be supported to hold the weight of a solid mass ? Simply adding a few blocks under the floor joists is sufficient. Your RMH does not "HAVE" to be on your slab... People routinely use bricks laid horizontally on the floor with air gaps between , then place concrete board on top of the brick. You build your entire rmh suspended 2" off the floor. You protect the floor from excessive heat, you gain another side of the mass to radiate warmth into your home. And in your case you might find that you have room to make a traditional bench! That should give you some options to concider.
Now lets talk about brick bells or another name is a stratifacation chamber. I looked and this is not in the builders guide that I could find. Plenty of info here at permies about bells.
Here is a link to a post descibing a ladys build of a small brick bell using a batch box design rather than a J tube design. She had limmited space (much smaller than your slab) and she built a superb little rmh to heat her home... You will also no matter what style or type of RMH you proceed with. (permies.com/t/43809/Masonry-stove-diy-build-feasible) its a long post but worth reading.
A brick bell RMH has a core unit the same as a bench style , risers are the same. The difference is that there is no pipes buried in a mass. This allows your RMH to go vertical rather than horizontal. Saving space on the footprint .The hot air from the riser enters your brick bell and rises to the top. This causes the cooler air to sink towards the floor. Your chimney attatchment is located at floor level. Only the coolest air leaves . The entire brick box heats up and radiates warmth thru your home. This is similar to a Russian masonry stove but not built by a certifed Mason. Unfortunetly the insurance man likes Masonry stoves because they are universally accepted as a safe form of wood burning in a home. A RMH is also a safe form of wood burning... but your insurance man will not understand this...
This is enough food for thought for now. Come back and let us know what you are thinking. I've included 3 photos showing you my traditional rmh with bench and my brick bell rmh (that uses a barrel for instant heat) Lots of options including the choice of bulding materials for your core.
I'm not claiming expertise in this area but I have read some things about galvanized metals releasing unhealthy fumes when heated, they might have to get pretty hot before being dangerous, but you might consider using a different material in the long run. I did the same thing a while back in a little tiny cabin of mine and someone mentioned it to me, best of luck in your project! -Aaron
posted 3 months ago
Thanks for the info Aaron, i didn't know that, actually that heat shield was meant as a temporary solution until i get my RMH.
Thomas, my chimney is metal, 6 in diam. The double insulated part is about 6 ft long from the ceiling straight through the attic to the roof.
The floors aren't done yet so it's just plywood sitting on 2x6s.
Thanks a lot for all that info, lots to chew on. Looking at at glance it seems like my best option might be something like Galabriel Freden did. I guess i have a lot of reseach to do.
I want to make sure that whatever i chose will be the most efficient for my house and that i can use sticks, not chopped wood as I'm not interested in cutting trees and chopping wood.
Thanks again for all your help.
I'm sure I'll have more questions in the future though 🙂