2022 Rocket Mass Heater Workshop Your chance to get up close and personal
with some of the most famous rocket mass heaters on the planet.
October 10-14, 2022
In light of the massive push to capture last year's Rocket Mass HeaterJamboree and massage it into the new Rocket Mass Heater MOVIE, we thought we'd do something a little different this year. We invited Uncle Mud (Chris McClellan) to host a Rocket Mass Heater workshop, taking participants through a deep dive into some of the workhorse Rocket Mass Heaters at Wheaton Labs. The undertaking will include deep maintenance on these builds, making some much needed improvements and enhancements, and making sure they are in tip-top running shape for when the weather takes a mega dip for the winter.
Shop - Batchbox Workshop Heater The workshop at Wheaton Labs is hard to heat so it needs a powerful heater. It is also long and narrow, and the low ceiling and walls are wood framed, so the heater can't be too big. If you have a problematic space like this you might want to join us as we build a low mass seven inch batch rocket heater optimized for quick heat output. It has batchbox w/ main barrel stratification and a second barrel stratification chamber to get as much of the heat into the room as possible.
Red Cabin - J-Tube RMH w/ pipe mass The Red Shed is a favorite sleeping spot for guests and residents but even with its new insulation it can get pretty cold overnight in the deep of winter. The larger new J Tube Rocket Heater (8" instead of 4.5") will nearly triple the available heat which will allow us to double the size of the exhaust pipe pebble mass storage under the bed for better overnight heat. We will also take the opportunity to cob together the rocks in the mass bench to make a better thermal connection between the exhaust pipe and all the bits of mass rock that store the heat for later.
Library - Overhaul RMH w/ stratification mass The Rocket Mass Heater in the Library is a fairly strong heater, but it has been through many experimental modifications and revisions. We will take it apart, inspect it for damage and poor performance, then rebuild it with a new horizontal stratification mass.
Ticket prices: $850
Accommodations: Camping (tent/RV/car) is free at all events...though since this event is in October, there's some other options, too.
(2) Slumber Party in Cooper Cabin: $100 for the whole event to sleep in the main room of Cooper Cabin
(3) rent somewhere nearby
Uncle Mud (aka Chris McClellan) raises free-range, organic children in the wilds of northeast Ohio. Between building things out of mud and junk he writes for Mother Earth NewsMagazine and teaches simple DIY skills at workshops and fairs.
Isaac Workman became interested in Permaculture in his teenage years. After attending a PDC in 2016 he decided this would be a direction he would pursue for his life. Since 2019 Isaac has been pursuing opportunities and projects including the 2021 Rocket Mass Heater Jamboree. Isaac often spends his other time working on sailboats.
*Three simple meals a day will be offered at no charge, but food is not included with your ticket. If you have special dietary needs/desires, you might want to bring your own food and use our rocket cook stoves, ovens, solar ovens and other cooking contraptions.
Arrival: Day Zero (October 9th - the day before the beginning of the event) Register and get settled in.
airport pickups: 10am to 5pm
arrival by car: 1pm to 5pm
I purchased a ticket for my son, Talon BearMedicine Ulrich, and then a ticket for his friend Cory RedHorn when I saw the gift purchase icon. Now, I can not figure out how to print a ticket for my son. So, except for him with Cory Redhorn. Make sure they stay in line and are polite! They both just graduated from Blackfeet High School here in Browning Montana.
Gotta say this somewhere. Hopefully there will be pics later - maybe even a youtube video ...
There were three projects happening at the same time:
- a simple 6 inch j-tube in the red cabin (try to video to save the about-to-be freezing people in europe)
- a 7 inch batch box in the wood shop (some exceptionally cool stuff there)
- overhaul the 8-inch j-tube in the library (this is what I want to talk about right now)
The library rmh has always been ... okay. Lots of experiments. Lots of testing. Not a super strong draw. So the mission was to take out all of the experiments and make it a super-star performing rocket mass heater.
In the end - we did that. And so much more.
There is a very twisted thing happening in my brain. We can heat a home with one tenth the wood. And "marketing" says I should say "heat your home with half the wood" but my engineering brain says "there is still heaps of room for optimization - I think we can do this with one twentieth of the wood ..."
replace double loop-de-loop with huge barrel stratification chamber: Hot gasses, about 300 degrees enter the barrel and go to the top of the barrel. The vertical exhaust is at the bottom of the barrel pulling up the cooler gasses at the bottom - about 110 to 115 degrees.
add some big rocks and cob to the top of the barrels to grab more heat to give it off later: making this a sort of cob/pebble hybrid. The best of all worlds. Cob and rock placed along the top edge of the barrel will harvest the heat in the barrel through conductive heat - the most efficient form of heat transfer.
six inch vertical exhaust: Arguably too small for an 8-inch system. But for this experiment, we want that. With an 8 inch vertical exhaust, a small bit of air is constantly pulled through the system when there is not a fire - pulling the heat out of the mass and taking it outside.
kiss the barrel: having the vertical exhaust super close to the barrel makes the vertical exhaust be a tertiary thermosiphon when there is a fire. This helps create a strong draw when there is a fire, and allows the system to plug a bit better when there is not a fire. To accomplish this we moved the whole core closer to where the vertical exhaust would be - which was where the hole in the roof was. So the whole rocket mass heater became about 14 inches shorter.
two more inches above the riser: the system was still running .... okay. We want magnificent. Time to do some "lawn chair design" (where you patiently sit and try to figure it out). When a fire is running, we are seeing the top of the barrel get quite red.
While that is great for boiling water, it suggests that there might not be enough gap between the top of the riser and the barrel.
We decided to pop off the barrel and measure the gap between the top of the riser and the barrel. If it is 2 inches or less, let's change that to 3 or 4 inches. ... 2 inches. So we added more than two inches below the barrel. Test: the system is now performing MUCH better. But we want it to be even better still.
two more inches below the juice box straw: Where the vertical exhaust comes to the bottom of the stratification chamber (juice box style), we started with a 3 inch gap. Let's adjust that to be 4 or more inches. The first test was for a 7 inch gap. Now the whole system had an incredibly excellent draw! Magnificence achieved! After a bit of lawn chair design, we decided that the whole system perform about 10% better if we dropped it to 5 inches. Done. Magnificent performance and the coming winter will give us some ideas about overall efficency.
There were loads and loads of other improvements - but they were a bit more about patching holes in the wall from previous experiments, adding steel supports across the box to prevent bulging, and stuff like that.
Here is the grand summary of what I think is accomplished here: The whole system will burn cleaner and faster. Less heat goes out the roof during the burn and the space is heated faster when there is a fire. And the biggest improvement, I think, is the efficiency between burns. The mass will hold a bigger charge and less of that heat will go outside between burns. Rather than burning a fire every other day, the people in that space might go an extra day or two until the next fire.
The general design is to have a magnificent and efficient burn during the fire, and to PASSIVELY plug the system when it is not burning.