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Post by volker on May 5, 2017 4:49:03 GMT -8
Dear Sirs, i plan to experiment with building a rocket heater which will directly heat my pool without the need for a heat exchanger. I plan to place the heater about 30-40cm below the watersurface into a water stream from pump. The construction will be executed in stainless steel - approx 3 mm - which will be cooled by the surrounding water. The basic idea is to modify the design from Takeshi Ueno www.youtube.com/watch?v=d9jQukYHtn4 by - extending the 1st and 2nd air tube upwards to the mass feeder about 30cm - modifying the 3rd air to allow airflow tom top-to-bottom Do you know anybody who tried a similar concept before already? I would be very happy to get some constructive input and design ideas. Or is the idea too crazy? Cheers, Volker
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Post by peterberg on May 5, 2017 6:00:30 GMT -8
Hi Volker, welcome to the boards.
I am sorry to say, it might work but combustion will be far from complete. The necessary high temperature for clean burning won't be there so there will be smoke outside and tar inside the stove.
First rule of wood burning: allow the combustion to be complete before extracting any heat.
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Post by gretchen on Jul 12, 2017 21:13:19 GMT -8
What about putting the horizontal pipe in the pool instead of in a bench? Then the combustion chamber would be more complete, the water would absorb the heat instead of the bench, and the hot area on top of the barrel can be for cooking lunch for all those hungry swimmers. Stove would probably need to be lit daily, and maybe twice a day or more (depending on ambient temperature and size of the pool. Below the boiling point, water is a great storage system for heat! Might have to protect swimmers' feet from the pipe, and have a really good cleanout access at the U turn since more soot would build up with the pipe being water-cooled than if it were going through a cob bench.
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Post by apollokit on Jul 18, 2017 5:01:13 GMT -8
I plan to experiment with building a rocket heater which will directly heat my pool... Or is the idea too crazy? Cheers, Volker Hi guys. I'll planning the same but instead of heating a pool, I want to heat whole house. I collected some pieces of information about "How to heat a water" so I can share my thoughts with you. In my case I'm going to build a water jacket above the heat riser (imagine yourself a double barel) but you know what? We look for impossible. There are already a better and a proven solutions. E.g. check this sound: This is Karher HDS water heater. Turn it around and imagine yourself that you place it above heat riser. If your burning is clean, you can get hot water fast. This is my theory but I think it will pass the exam. There might be only one problem. To adjust it to the right dimensions.
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Post by Donkey on Jul 20, 2017 19:28:51 GMT -8
apollokit, That will certainly work, though you cannot turn a wood fire off so easily as a gas flame (unless you use wood-gas), as a result wood fired systems can become a bomb more readily. Be very aware of safety equipment for hot water systems and provide backups/redundancy. gretchen, That's exactly what I've been thinking. (or something like that) What if it was a metal bell chamber just under the water level, with insulated input (from the stove) and chimney on. Then the J-tube (or Batchrocket) can be outside the hot-tub/pool, easy to feed. fully insulated, etc. It would have to be bolted to the side pretty well, it's going to want to float out with some oompf.
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Post by Donkey on Jul 20, 2017 20:20:49 GMT -8
Wood provides 6000 BTUs of heat per pound (yes, theoretically it's 7000 BTU per pound, but realistically I just use 6000) One BTU is enough heat energy to raise the temperature of one pound of water, one degree Fahrenheit.
How big is your pool?
Let's say I want to heat a large hot tub, which holds about 800 gallons of water. (it's capacity is really bigger than that but the heat exchanger and the people will displace some of the volume, etc.) Water is 8.35 pounds per gallon, so an 800 gallon tub holds 6680 pounds of water. Let's say the initial temperature is 68 degrees F. and I want to heat the water to 108 degrees F. (a change of 40 deg. F.) It looks like we can safely round off here (just call it inefficiencies in the tub and other bits) and make a local rule that one pound of wood can raise the temperature of our tub about a degree F. That gives us as a thumbnail estimate of around 35 or 40 pounds of wood for a sweet evening under the stars. Colder nights and colder water will require more wood. How many gallons of water are in an average pool??
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Post by Dan (Upstate NY, USA) on Jul 21, 2017 1:02:06 GMT -8
Best way to heat a pool, most gain for your money listed in order.
#1 put insulation between the ground and the liner (Above Ground) or btwn the ground and the bottom and sides (Below Ground). Most heat losses come from ground contact.
#2 use a clear solar cover. Second biggest heat losses is from evaporation at night with the cool night air vs warm pool water. (Saves on water losses in dry climates too)
#3 solar coils after your pool filter
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hastingr
New Member
Proprietor of East Texas Aquaponics in Mineola TX.
Posts: 1
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Post by hastingr on Oct 25, 2017 18:05:23 GMT -8
I have the plan to use a rocket mass water heater using the batch box. I am heating a 27,000 gallon aquaponics system. I am in Texas, so our winters aren't too cold, we hit 12F two nights last year. The water temp of the system got down to 51F for a day. What I need is to keep the water temp above 60, as best I can, so I need to move the water temp maybe 6-9 degrees F above it's natural level. In otherwords, it has to be pretty darn big. I think it has to be a 10 inch system.
The top of the riser would do a 90 degree turn, and there would continue to be an insulated stainless tunnel. The tunnel would travel maybe 6 inches, then turn a right angle downward (this part is not insulated, of course) into a vat (in this case, an insulated IBC tote) Down near the bottom of the tote, it would turn a right angle go a few inches, and then turn up out of the water turning into a chimney pipe, hopefully with most of the heat extracted into the water.
I think I need something north of 180,000 BTU/hr , and a 10" might do it, though I haven't the data to be certain. So... What do you fire nerds think?
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Post by Orange on Oct 26, 2017 3:17:18 GMT -8
I like the idea of direct fire instead of heat exchanger! So far i've only seen this type
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Post by apollokit on Nov 2, 2017 8:51:35 GMT -8
As I said. I was planning to build rocket stove with water heat exchanger So.. After some period of time I did it. Here's what I did: And here you can view whole album of this:
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docbb
Junior Member
Back from ZA
Posts: 92
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Post by docbb on Nov 2, 2017 20:07:27 GMT -8
As I said. I was planning to build rocket stove with water heat exchanger So.. After some period of time I did it. Here's what I did: No more P channel and a metal riser as i can see ? Any reason?
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