Post by marcos on Oct 19, 2020 6:24:16 GMT -8
I'm wondering how much mass to put above and below my split barrel bell/ stratification chamber in my RMH cob bench? It will be sitting on a raised platform over a wooden floor. See images below. The challenge I'm facing is how to get enough mass under and over the split barrels without raising the bench up too high and making it uncomfortable to sit on. Comfortable bench height is considered to be 18" I'd like to keep it to 20 - 21". The platform eats up 3.75", a split barrel sits 12" at the highest point, In the Rocket Mass Heater Builders Guide, E &E Wisner recommend 4-5" under and 4-6" over stove pipe buried in mass. Add it up (using the lower numbers) and you get 23.75", too high for a comfortable bench. Options I'm considering:
*Cut some off of my barrel split to lower the peak height.
*Fill the floor of the split barrel in with some mass (in my case, bricks or cob, which is kinda similar to the first option I lean towards bricks, for a flatter surface that's easier to clean of ash). I These two options reduce the internal surface area a bit.
*Put down a layer of insulation (CFB or Clay-perlite) under the barrel split in order to protect the wooden floor beneath , then cover with a few inches of cob or brick.
Does a bell / stratification system require the same mass over and under as a stove pipe system? I'm wondering if the temps on the floor of the barrel splits will be somewhat cooler than a pipe, so I could get away with a little less mass? Any guess what temps I can expect in the split barrel intake and exhaust? This is a critical design decision i don't want to mess up - don't want the base to get so hot that it damages the floor, not do I want the bench so high that it's uncomfortable to use.
*Cut some off of my barrel split to lower the peak height.
*Fill the floor of the split barrel in with some mass (in my case, bricks or cob, which is kinda similar to the first option I lean towards bricks, for a flatter surface that's easier to clean of ash). I These two options reduce the internal surface area a bit.
*Put down a layer of insulation (CFB or Clay-perlite) under the barrel split in order to protect the wooden floor beneath , then cover with a few inches of cob or brick.
Does a bell / stratification system require the same mass over and under as a stove pipe system? I'm wondering if the temps on the floor of the barrel splits will be somewhat cooler than a pipe, so I could get away with a little less mass? Any guess what temps I can expect in the split barrel intake and exhaust? This is a critical design decision i don't want to mess up - don't want the base to get so hot that it damages the floor, not do I want the bench so high that it's uncomfortable to use.
Any input welcome! Thanks!