Credit: Kevin Murphy
Paul gave an in depth review of each of three rmh designs. One design by Paul, one by Ernie and a third by Erica. There was a review of rocket mass heater of the shipable cores. There is a fire problem in Paul's box design due to lack of insulation. 3 cores were built during the first workshop. First was Ernie's cob like core. Castable manifold footprint is most the difficult piece. Ernie likes partial barrel. Paul thinks its prone to leakage. Lots of tape and glue used which Paul doesn't like. Welding can replace tape but not easily welded. Ernie uses a small firebox called a puppy burner. First try failed due to a lack of insulation. Paul wants a design that will keep material costs around $100. Erica had a design that used a special goo. This goo made her manifold very light which Paul loved. The first core design with manifold design. Paul not a fan. Paul's design had 3" on bottom clay and perlite. Bigger safer but heavier. Four people to move it. Pocket rockets were plentiful. Less finicky. These were quick and simple. Shipable core design workshop used tried and true methods. Paul suggested using duct in place of stove pipe. The pebble style design will be tested this winter. Erica gets scientist of the year for her light weight design. There was a discussion of the cob style design and cost associated with it. Paul likes the idea of a shipable core in a wood box. If Paul can combine his design with Erica's light weight this would minimize shipping costs. A discussion of the shipping costs followed freight versus UPS and FedEx. A discussion of how to vent the rmh was reviewed. Thru roof versus thru wall was debated. Both have their pros and cons. Paul stated that air intake design can be problematic.
The tipi was reviewed and the cob style rmh built in the tipi was discussed.
Workshop for set for September of 2014 were set. October was just a little to chilly.
The first wofati and the progress on the building was discussed and some plans for 2014 were mentioned.
podcast 414 – The problem with batch box rocket mass heaters – Part 2
podcast 413 – The problem with batch box rocket mass heaters – Part 1
podcast 412 – Building a better world
podcast 411 – Foody bits – Part 2
podcast 409 – Listener questions – Part 2
podcast 403 – Bits and Bobs towards Critical Mass – part 2
podcast 402 – Bits and Bobs towards Critical Mass – part 1
podcast 401 – Permaculture Design Course for Scientists and Engineers