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Credit: Cassie Langstraat

In this podcast Paul and all of the innovators discuss the most recent rocket mass heater workshop/innovator's eventthat just finished at the labs. The first project they talk about is the standard 8 inch cob system with no frills and no bells and whistles, that was built that into wofati 0.8. They got word that Tim and Christy burnt it and it was too hot all night. This is good news because when they initially tried to start it, it was smokey and smoked back but that was due to the conditions. Paul does mention that they will do this event again next year but possibly 3 weeks later in the year, so that it will be colder.

So the standard 8 inch cob heater didn't work right at the beginning but they mention that that is totally normal, it is how it is supposed to act. Tim set up a vacuum cleaner to get the temp to rise in the chimney section until it is warm enough to run on its own.

Ernie and Erica talk about how this winter they used a very very small amount of wood, even in comparison to their neighbors with a smaller home. Paul wonders if is it a possibility to only burn every other day or so in the wofati and the crew says that if the wofati gets finished, yes. The other wofati, wofati 0.7 has no heat and they need to see how cold it gets so they will have someone live in there this winter to fulfill that experiment. Erica talks about the heater in the wofati, how if you are in a climate where the temp is cooler on the inside that you will need to probably have a smaller bench.

They discuss the mold issue they had. Erica talks about how they tried to push the project to get finished in the shortest amount of time possible so there ended up being quite a lot of moisture in it and the straw had some sort of mold and so there is some mold on the bench which Paul says will go away in a few days. Erica says there just needs to be an increase in the ventilation help dry it out faster or use a different plaster that has more anti mold properties, typically ones with manures.

Next they talk about the manifold and how this is the part that most people have trouble with. They express the details of the manifold and how it helps to do some sort of small scale molding with soup cans and play dough to get people to understand it. Paul mentions that maybe it's time to put together some videos and manifold needs to be a big part of that.

The next thing the crew talks about are the test results. They used the test-o-meter for the heater at basecamp and Ernie says that it basically told them that it works within certain parameters but it is inconsistent so there is room for improvement. Erica mentions they were getting pretty decent parts per million on carbon monoxide but not as good as Peter.

They discuss the idea that the more efficient the stove, the harder it is to start. By necessity, it will be harder to start in adverse conditions like starting on a hot day, because its colder on the inside it makes it pretty hard to start. This was what happened at the labs, by the way.

Tim, who was the farm manager at PRI for a while, talks about how he has many stories but the best thing about PRI is the people. He talks about this deluge at the PRI farm and how Geoff had everyone go out there in the torrential down pour to go out to see what the swales are doing and that is one of his favorite stories from the PRI.

Next they talk about the tours and what everyone thought of the place. They begin by sharing their experiences with the the hot water from compost showers. There is a pipe through the pile, but it's clean water that never touches the urine. They then talk about pooping in the pooper and Paul asks if it is nicer than pooping in the house. Tim mentions the nice view and they discuss the diverters and a bit about the differences between women and men's peeing anatomy.

Next they mention the berm near the house that is immense and that they will get it planted soon. The tour goes into the office where there is a rocket mass heater. Paul talks about how there have been a couple of discoveries in this area. They talk about the exhaust going through the roof, Paul believes the vertical chimney is 2.5 times more powerful than the heat riser.

They say how if you route it out the wall or roof it barely keeps the fire correctly and the odds of smoke back are huge. But if switch off the bypass and route it through the mass Paul thought there would be a huge difference, but actually made very little difference. They say how this is because there is not a lot of drag in the system. Everything is smoothed out with the pipe and that system in that configuration is so on the edge of efficiency and will pump heat into the rocks. They discuss the issues they have with the ceiling at the labs. If they had a better ceiling, the hole out the wall would probably work ten times better with the hole out of the wall.Erica talks about this affects the pressure in the building. Peter talks about different height of heat risers and Paul says he has learned a couple of new things that are about getting a much cleaner burn.

Relevant Threads

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Rocket Mass Heater Compliance Code

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