Paul Wheaton talks with Ernie and Erica Wisner about rocket mass heaters. They talk about the boom-squish podcast Paul did with Caleb Larson on heating water with a rocket mass heater. They talk about heating coils, and the importance of a tall and vertical heat riser. Ernie talks about all of the testing he has done on his own time, and his frustration with people "innovating" stupidly and incorrectly calling what they make a "rocket mass heater." It is important people read the abundant information available on the wood burning stoves forum before burning Ernie and Erica out on asking already asked questions, and get a good, safe foundation of things before building one yourself. Paul talks about legionella bacteria. They have building plans on the way for their double chamber cob oven, which will be good documentation for people trying to follow building code. Ernie and Erica will be doing workshops at Yestermorrow (Vermont, September), The Newforest Institute (Maine, September/October), and they encourage people in the northeast and Great Lakes region to contact them about doing other workshops or builds, (as well as in Montana and Nevada as they will be in Reno in both March and June). Paul mentions how 11 days of Sepp Holzer and the PDC beforehand are currently filled but have waiting lists. Ernie and Erica respond to listener questions. What's the smallest rocket mass heater and largest rocket mass heater that are safe? 6"-10" (largest feasible). Ernie can make an 8" system that will be able to heat a 5000 sq foot house. Ernie says, if you don't want back-smoke: build it right. They talk about cleaning and easy maintenance. They talk about burning pine or damp wood. They talk about how safe rocket mass heaters are for pets and little kids. Rumford fire places are a smart use of radiant heat, that you can watch and enjoy. The idea of an RMH IS to have a prolonged chimney fire on purpose. They talk about converting using existing chimneys. They talk about rocket cookstoves. They talk about catalytic converters. Paul talks about his portable rocket mass heater. They talk about optimizing how rockety the heater gets, and the barrel. Ernie and Erica talk about possible experiments they would do if they had the budget. Erica talks about the need for rocket mass heaters in the world, and their passion for them. Paul talks about war and fossil fuels. Erica talks about passive solar being ideal, like Paul's wofati. Erica shares inspector stories, and ways to pass code with your rocket mass heater. Paul talks about playing by the rules vs. not playing by the rules.