Rocketstove Mass Heater in Western Pa

Glenn Herbert wrote:I'm sorry that nobody caught this before you started work. A standard RMH in the basement is unlikely to give good results; It needs tending every 15-40 minutes depending on circumstances, and works best when in sight and sound of main living spaces. One exception would be a batch box which is a fill and forget for the hour it takes to burn a load.

For a big old house, a 6" RMH is probably much too small. I think you need to do the work to move up to at least an 8" system. If you have a 40' chimney, you may have good enough draft that the existing chimney will work. I have a 7 3/4" J-tube RMH with bell, and a temporary 6" stovepipe only 12' high, and this works fine all the time unless there is a consistent east wind (rare except in spring). When I extend the pipe above the roofline in a few days, I expect it to work all the time.

Robert Dearborn wrote:Was wondering how you are progressing ?

bob day wrote:The combustion area of the stove is a place where the highest temps are necessary, and finding ways to insulate that area under and around the fire box, tunnel, and heat riser will reward with better efficiency. I always used firebrick splits to line firebox and tunnel (only 1" thick) for durability then clay and lots of perlite to hold everything together, insulate, and seal it all

So you build the entire firebox out of split firebrick?In the book the design is to build the riser out of split firebricks and the rest of the combustoin area out of full sized firebricks. Why you put also the clay first and then the perlite to insulate?I thought in the book the masonry around the firebox goes after the perlite covers the firebox.I guess it works both ways?

I will also second/third the idea that the batch burner design  will reward you more than words can tell,---- but if you really are impatient to get on and start doing something, at least leave enough room on the firebox side to expand into the batch burner design when you tire of the novelty of the RMH and the work/attention to keep it fueled.


I liked my RMH, but I love my new Batch Burner

If it wasn't the middle of winter and I wasn't already tired of all the changes I've been making, I would likely go straight to the double shoebox design recently unveiled--maybe next year--

It is the batch box's height that prohibits me to build one so i am also waiting for the double shoebox design which seems smaller and simpler .

thomas rubino wrote:Jay; I believe the recommended size is 5.5" x 5.5"  on a 6" J tube. Common practice is to make the height slightly more to allow for an inch of ash to cover the burn tunnel floor.  So a 5.5" wide by 6.5" tall would be a better size to aim for.