I’m designing a
RMH for a 546 ft2 addition in Northern CA, for my wife and I. We have a woodstove in our existing house, which also provides
hot water, the
RMH will heat the addition. The
footprint of the RMH is about 8.5 feet by 40 inches wide, about 18” high. Based on the sizing calculation spreadsheet available on bathrocket.eu, my heating needs needs fall somewhere between a 6” and 8” system. I am leaning towards a six inch system, largely due to space- I have a fairly small house and for 8-9 months of the year do not need a fire (and then have 3 months of winter with the stove going all the time). The footprint of an 8” system would be just a little too large for us, though do-able. I’d love to hear some opinions, especially from folks who own and operate a RMH .What do you recommend, a 6” or 8” system? Folks who own and operate a 6” system – do you feel confined by the small
wood? Does it require more than 2 firings per day? What space are you heating with it?
Here are some pros and cons (Thanks to Luke Parkhurst who is helping me with this design and install):
Eight Inch System:
Pros: Can accept larger diameter wood. It will most certainly be large
enough to heat the space on even the coldest night. An additional bell/masonry piece could potentially be added in the future to capture more of the heat.
Cons: Will need to change out the existing pipe. Slightly more expensive (core will cost $325 instead of $200, plus the 8" pipe will cost more). Needs a 55 gallon drum/slightly larger core footprint as well. Would likely be sending extra heat up the chimney (i.e. losing some efficiency/burning more wood).
6"System
Pros: Smaller footprint. Ideal for burning prunings from the orchard and smaller limb wood. Existing piping is already 6". WE have an existing . Given the size of the bench we discussed the 6"
should provide plenty of heat to charge it up.
Cons: Restricted to smaller wood, more time splitting, possibly not warm enough for the coldest nights(?)
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