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Post by excitingrockets on May 4, 2014 3:26:14 GMT -8
Sharing and discussing ideas always gives me a big on da face, especially when it is about creating a nice and warm climate inside. Looking at the energy requirements of a new home that I am planning to build, I found that a very large part of energy needed is to enjoy warm water. 30C for floor heating, 40-90C for washing, 60C for shower and taps. Because I enjoy stoking fire I am looking at a combination of solar and rocket stove to keep one or more insulated water barrels warm. Therefore I am very interested in your ideas / experiences with using water for heat storage.
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Post by Donkey on May 4, 2014 7:53:09 GMT -8
I'm NOT a fan of using water as a thermal mass for heating spaces. On paper it sounds good but in reality, water presents more difficulties than it's worth. In my opinion, unless you have some particular problem that only water can solve, you'll be better off with a solid storage medium. On the other hand, everyone loves hot water. I've got a design that I haven't tried yet over here: donkey32.proboards.com/thread/1096/hot-water
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Post by excitingrockets on May 4, 2014 8:26:51 GMT -8
Thanks Donkey! The design and string with reactions is very helpful.
A great thing about hot water is that it easily travels around the building and floor heats all rooms. The point is that there will be a hot water heating system around the house anyway so why not use a rocket to heat the water on cloudy days?
What difficulties do you refer to? I am aware of the danger of exponential pressure increase when water becomes gas. What other difficulties would you warn for?
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Post by patamos on May 4, 2014 10:03:56 GMT -8
Water has a low phase change temperature. Rockets fire well above that temperature. Overheated water can make for a rapid onset catastrophe... So you have to make sure that the sensory feedback and mitigation systems are very reliable. Given that most such systems are electro-mechanical by design... system failure is always a lingering concern
The design that Donkey has linked to is beautiful in that the controls are relatively passive.
If you are looking to install solar/rocket hydronic systems you might want to check out 'Solar Sand Bed' and 'Annualized Geo Solar' heating. Wherein the heated fluid is dumped into a large earthen mass for a very long flywheel effect. Aside from one or two circulating pumps, these approaches can be very simple.
well being
pat
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Post by excitingrockets on May 4, 2014 12:46:01 GMT -8
Thank you Pat!
Positioning the water exchanger far enough from the big heat, or even plastered away in the cob mass, would be the least precaution to take I guess.
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Post by talltuk on May 4, 2014 13:39:11 GMT -8
I have been refining my theories for a similar build for the last couple of years. My current thoughts are to use a recycled oil boiler with pipes as large as I can fit for thermo syphoning. A simple In pipe thermostat(mechanical) can be used as a heat dump to a radiator if the pipes get above 80oC. A pump will be attatched on a bypass to the flow designed to kick in at 90oC. All this will br hooked to an accumulator, a very large hot water cylinder that can also take a solar coil. The accumulator has a coil to run mains water through for hot water and you can pump away from it to any heating system. A third saftey circuit is fitted with a pipe thermostat and pump in case of over heat. The other nice thing with accumulators is it takes quite a while to heat all that water, so as long as there is flow it should work nicely. I will be posting my plans at some point when I can write it all up. Oh and the accumulator is vented to the atmosphere, over a fill and expansion tank above it. Less chance for big bangs.
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Post by Donkey on May 5, 2014 8:03:40 GMT -8
What difficulties do you refer to? I am aware of the danger of exponential pressure increase when water becomes gas. What other difficulties would you warn for? Water, the universal solvent, wants to get out of whatever you put it in and given enough time it will. Pumping the stuff around means moving parts, junctions, piping, and their accompanying complexities. With hot water comes possible mineralization problems which can plug up the works, fail pumps, etc. I always ask myself this question: Does this idea here (whatever it is) solve more problems than it creates or not? Anything you do will have upsides and downsides, all solutions to problems cause other problems, from simple issues like "how am I gonna build this" to "how can I keep my family safe from this".. You don't always see ahead to what the compounding issues may be, but you should ALWAYS take the time to try.
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Post by Monsanto on Mar 1, 2015 15:33:21 GMT -8
Excitingrockets, as some months have passed since your original thread, I am curious to know if you were successful in incorporating hot water storage. The concept that you explained is exactly what I had in mind. Martin
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Post by excitingrockets on Oct 21, 2015 7:19:31 GMT -8
Thanks Donkey, your view helps me to keep realizing the value of keeping things as simple as possible.
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Post by excitingrockets on Oct 21, 2015 7:26:47 GMT -8
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Post by Monsanto on Oct 23, 2015 12:23:20 GMT -8
Excitingrockets: We live in Portugal, in the parish of Monsanto. The village of Monsanto is near to the top of the steep sided hill in the sunset as seen from our house. Thought it might provoke some GM response, but so far so good. Martin.
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