Jeff Thorpe

I'm in northern VT, too.  What are you looking to know?

When I saw him securing copper tubing with galvanized steel pipe strapping to the riser, that was my first thought too - galvanic corrosion. I'm very curious how much power he can get this to put out - the inventor claims this will put out 10hp, I guess you could say I'm a little skeptical.

Troy,

Thanks for the counterpoints, I hadn't seen anything critical of the green steam engine. After checking out all the criticism, I almost wrote that option off. But there is one guy on YouTube (https://www.youtube.com/channel/UCNwdzF4vPS-nNnDbMcaSwiw) who has built a steam engine and monotube boiler, and he's put about 50 videos up detailing the build. He's got the thing built and currently runs on compressed air. Looks like he'll have the thing running and making power on steam in the next few months. I'll watch and wait to see how it performs.

Jeff

I'm working on a similar design for my greenhouse, but I'm in a heating climate so we're using the tubes to dump heat into the earth below and around the greenhouse to help hear it in the winter. Always use perforated drain pipe. I wouldn't bother fooling around with barrels of water underground (that's what I understood your post to suggest), not much Mass difference than the surrounding soil. One thing you have to keep in mind is the velocity and dwell time of the air in the tubes, and whether you're looking to cool passively or with electric fans. For a climate battery, this means burying 4" perf ads tubing every couple feet on center and every 1' vertically, and connecting to much larger plenums at each end. For us, a major part of the design is the condensation of water vapor in the running, and the subsequent release of stored energy from the water vapor and into the soil. I imagine that would be less of a factor in Arizona.

I'm thinking of doing something similar, Thomas. Have you seen the green steam engine. Com website? They sell Steam engine and boiler kits that are much less expensive than the mike brown engine you mentioned. My understanding is that a tube boiler is quite safe without the explosion risk of a conventional boiler, and it also lends itself well to integrating into an rmh (you've just got to put a copper coil in there somewhere). A proper pressure release valve and you're good. I want to build an rmh with tube boiler in my greenhouse to heat the gh and my home and power a 10hp green Stream engine. The boiler will also provide a source of steam (Steam sauna, anyone?) And distilled water. If the exhaust from the rmh is as clean as they say it is (this would need to be field proven), I could feed the exhaust into the climate battery of the greenhouse, making the rmh truly 100% efficient with the added bonus of dumping all that co2 into the gh for the plants. Like I say this would require proofing with a gas analyzer for sure, but incredible possibilities for an off grid greenhouse/home with some old/low tech!

Larry,

Thanks for the reply, I'll check out your links later. After doing the calcs I realized that water in an open system really isn't capable of storing a vast amount of heat like I thought it would. I've been wondering a similar thing as one of your ideas - if it wouldn't be easier to bury some coils in firebrick or cob? Storing the heat in solid form instead of liquid - the bricks can be heated up to 800 degrees or whatever, then just pumping water through the coils should extract that heat fairly well. Obviously preventing a steam kaboom would be important, and you'd have to protect the copper from both flue gases and cement.

I haven't thought about this much, but another idea has crept into my mind - everybody is afraid of steam, but what if we just acknowledged the power of steam and built a steam system? Instead of trying to prevent steam, using steam to our advantage? People have been building steam systems for 150 years, and you can readily get old steam radiators pretty cheap....?

Eric,

I haven't started my project yet - I'm still in the research phase. I'm leaning away from putting a coil around the barrel, and in fact leaning away from a hot radiating barrel at all and am going to build something that stores more into mass:

http://www.dragonheaters.com/6-rocket-masonry-heater-castle-build-kit/

Given the potential dangers involved in heating water, Erica and Ernie have shied away from discussing this subject in these forums, which is why threads like these don't go far.

I found another forum where it's talk of RMH all the time (including heating water):
http://donkey32.proboards.com/thread/1232/water-heat-storage


I'm thinking about putting a (probably unpressurized) storage tank inside the rocket mass heater. Thoughts range from a 30 or 55 gallon barrel with a copper coil submerged in it, to a 40 gallon water heater (with the jacket and insulation peeled off), all the way up to the insane and ridiculous idea of using an old 250 gallon oil tank.

My goal with in designing this heater would be to burn for a few hours in the evening and have enough heat stored to heat my 1800' house overnight. Once or twice a year it will get to -30F here, but usually winter nights are around 0F in February. So how much heat do I need? That is the question.

Running some quick heat loss calculations on the house, I come up with 14,000 BTU heat loss per hour. If I want to go for 10 hours overnight, I'll need to be able to store 140,000 BTUs.

Theoretically we will only be able to extract 80 BTUs per pound of water (water boils at 212 obviously, but the radiators require water in the 130-140 range. 212-130=82. I'm going to use 70 in my calcs, because water doesn't like to stay at 212.

140,000/70=2000 pounds of water. water is 8.3 pounds per gallon 2000/8.3 = 240 gallons.

So it looks like I really may need a 250 gallon tank. Not sure if that's practical, and how long it would take to actually heat it up. It may be necessary/simpler to use a 250 gallon tank remotely, and put a smaller tank in the RMH, and feed the bigger tank with a pump or thermosiphon.

I've been thinking the same thing. Why go to all the effort of splitting cordwood, drying it and then splitting it into small chunks for use in an RMH? Why not just use stick wood, or Coppicing? I'm planning on planting some fuelwood and pollarding it for use in my soon to be built RMH, I want to try Willow, and Black Locust. Black Locust is very fast growing and has some of the highest energy density for wood. But coppicing willow has been done for thousands of years for basketweaving, furniture making, etc. Willow also has the advantage of growing straight rods that are 6'-10' in a single year. I want to design a feed tube for my RMH that will load 6' rods that will gravity feed into the burn chamber. Why cut, split, stack, re-stack and dry, when you could just cut long thin rods that don't need to be split or cut to length, and will dry in a fraction of the time as cord wood. Here's some relevant links:

http://www.esf.edu/willow/documents/VolkWillowOverview111110.pdf
http://www.doubleawillow.com/publications_fact_sheets.php
http://www.thewillowbank.com/willow.firewood.facts.htm

We had a similar experience last year. There were two skunks coming around the chicken coop (we never locked the door up at night). They would eat a few eggs, but leave the chickens alone. One afternoon I went in to get the eggs and found one asleep in a nesting box. Banging loudly on a metal trashcan wouldn't even wake him up. I shot him and of course stunk the coop up for months. A few days later I had to shoot his mate, too. I should have let them be - turns out they were providing a service. In exchange for a few eggs, they would mark the coop area and keep other predators away - we never had any predator problems while the skunks were around, but within a week or two of eliminating them, a possum found its way in and gnawed on the ass ends of three ducks.

In hindsight I should have just gotten the eggs earlier in the day and paid the protection 'fee' (left a few for the skunks).

Great idea, Tony! I'm going to try this too.