Composting to Create Hot Water (transporting, water heater, purchase)

[Grassyknoll]

Came across this link today to a FB page where they discuss using large composting piles to create hot water (claimed up to 149f).

native power |

Seems like it would be a natural for Hawaii with the abundant materials available. Does anyone know if this has been tried or being practiced? I searched the forums but saw nothing directly related to the subject.

[KauaiHiker]

For most of Hawaii, it seems so much easier to have solar hot water panels that run automatically when there is sun, and an electrical element or inline gas heater for backup. All tried and true equipment that is easier to source.

The company in the video seems to have worked out some of the issues to make compost heat practical and easier to harness, but it's a long, long way from being implemented regularly in our climate. Also, without a local or even mainland supplier, forget about ordering the equipment--you'll have to DIY all the way.

But still it might be fun to experiment and make your own home-built compost heater, to see if it could be done. That might answer some questions about whether it would work in Hawaii.

[Grassyknoll]

Originally Posted by KauaiHiker

For most of Hawaii, it seems so much easier to have solar hot water panels that run automatically when there is sun, and an electrical element or inline gas heater for backup. All tried and true equipment that is easier to source.

The company in the video seems to have worked out some of the issues to make compost heat practical and easier to harness, but it's a long, long way from being implemented regularly in our climate. Also, without a local or even mainland supplier, forget about ordering the equipment--you'll have to DIY all the way.

But still it might be fun to experiment and make your own home-built compost heater, to see if it could be done. That might answer some questions about whether it would work in Hawaii.

All good points KuaiHiker. I might have to experiment a bit with a DYI system. I currently have an on-demand propane system and not solar. Though my current costs are such that I don't really see either solar or a composting system giving me much ROI at this time.

[davephan]

I don't think using compost to produce hot water would be very effective compared to other methods. I do have a compost pile and in the summer the compost pile can become very hot. Not hot enough to ignite on fire, but hot enough that if you stick your hand in the compost pile about 6 inches, you would burn your finger tips after a second or two. When the cooler weather occurs, the compost pile emits some steam in the air. In sub zero weather, the compost pile seems to produce no heat.

I think technically, you could produce some hot water, but it wouldn't amount to much hot water since a lot of the hot water would be lost when the hot water flows though the long pipe into the house, which might be a long distance. Since the compost pile does emit some odor at times, you would not want to have a compost pile too close to your home. Energy would be required to pump the hot water through the long pipe too. Transporting the hot water in buckets isn't very practical, unless you live in a third world area.

Hot water can be produced far more easily and cost effective from solar or conventional methods. I think it would be far more effective to invest the effort into yourself in the developed part of the world, so that you earn more money and can easily afford to purchase a more effective way to produce hot water, rather than trying to produce hot water using a novelty method.

[mdand3boys]

I have solar hot water here in Hawaii/Puna District and can easily go 4 days without it getting cold due to lack of sun. As easy as the system is to maintain (empty a couple gallons of water out of the bottom of the storage tank every couple months to reduce any sediment) I couldn't see the advantage of doing some sort of heating via composting solution.

[Grassyknoll]

So far I have had some great replies, but they have been more along the lines of "why use compost when you have solar". Unfortunately, this does not address my original question of whether it is being practiced in Hawaii.

I have looked into it a bit more and the concept seems pretty solid. There are numerous sites, videos and books showing the validity of the system. Some systems are nothing more than the constructed compost pile and several hundred feet of coiled 3/4" poly-tubing. If you were to set the system up as on-demand either pumped or gravity fed, I would think you could have a system for a fraction of conventional solar. Sure, there would be maintenance with the compost pile itself, but it doesn't appear substantial.
With the amount of compost-able material readily available in Hawaii, and the low cost to build for a DYI system, it seems like a natural.

So again, back to the original question I posited; does anyone know if this has been tried or being practiced in Hawaii?

[OpenD]

Originally Posted by Grassyknoll

So far I have had some great replies, but they have been more along the lines of "why use compost when Some systems are nothing more than the constructed compost pile and several hundred feet of coiled 3/4" poly-tubing. If you were to set the system up as on-demand either pumped or gravity fed, I would think you could have a system for a fraction of conventional solar.

I dunno, but that seems more expensive to me than any of the homebrew solar water heaters I've seen around. Basically they're a loop of tubing carrying water inside a collector/concentrator box. And it also seems like most folks in Hawai'i have more sunshine than compost. Still, if you're running a pig farm I suppose it could work, and as a bonus you could collect the methane to run a generator and then you could have electricity too!

Or, check the internet for DIY Solar Water Heaters... there are lots of designs to choose from. Why reinvent the wheel when there are so many already proven solutions available?

Good luck

[whtviper1]

Originally Posted by Grassyknoll

So again, back to the original question I posited; does anyone know if this has been tried or being practiced in Hawaii?

At this point I'd say -

Apparently not.

[Grassyknoll]

Originally Posted by OpenD

I dunno, but that seems more expensive to me than any of the homebrew solar water heaters I've seen around. Basically they're a loop of tubing carrying water inside a collector/concentrator box. And it also seems like most folks in Hawai'i have more sunshine than compost. Still, if you're running a pig farm I suppose it could work, and as a bonus you could collect the methane to run a generator and then you could have electricity too!

Or, check the internet for DIY Solar Water Heaters... there are lots of designs to choose from. Why reinvent the wheel when there are so many already proven solutions available?

Good luck

Good points OpenD and to be honest, I haven't priced either system. It is something I'll have to look into further though.
As far as reinventing the wheel, it's true nothing good comes of that, well other than maybe things like Apple, or maybe Tesla, Southwest Airlines, Starbucks....

[Grassyknoll]

Originally Posted by whtviper1

At this point I'd say -

Apparently not.

Well, whtviper, I realize three replies in a day and a half is a thorough representation of the collective experience of all CityData Hawaii members, but I'll hold out for maybe, just, one, more.