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Isaac Solar Ice Maker
- rgovostes 4y agoThe New Yorker recently published an article on the scarcity of refrigeration in the developing world: "Africa’s Cold Rush and the Promise of Refrigeration For the developing world, refrigeration is growth. In Rwanda, it could spark an economic transformation." https://www.newyorker.com/magazine/2022/08/22/africas-cold-rush-and-the-promise-of-refrigeration https://www.newyorker.com/magazine/2022/08/22/africas-cold-r...
- dvh 4y agoWhat happens when the ammonia leaks in to the river?
- bibanez 4y agoIts pH changes temporarily and that kills many species in the ecosystem if sustained. But it's far less toxic than other compounds or other types of spills such as oil
- abrax3141 4y agoAnd they’re already dumping way more ammonia than this could leak directly into the ecosystem via fertilization. It’d take a lot of these leaking to have much impact. (And maybe the plants around it will do better for a bit when it does leak! :-)
- BenjiWiebe 4y agoAmmonia is also naturally occurring, from decomposition of urine.
- jessaustin 4y agoAmmonia at standard temperature and pressure is a gas. It is poisonous to breathe if enclosed at sufficient density, but once it gets outside it's no risk to anything.
- ncmncm 4y agoA buoyant gas. It goes up. A potful of liquid ammonia boiling on the ground nearby can be bad, for a while.
- pfdietz 4y agoI'm reminded of what happened to solar hot water. It's now generally cheaper to use PV to drive a heat pump water heater. I suspect the same is true here -- use PV to drive an ordinary refrigeration cycle. And PV, unlike the concentrating collectors shown here, also works with sunlight scattered off clouds and clear air.
- cjrp 4y agoCheaper to install or cheaper to run? My understanding was that the solar heaters were relatively cheap up-front.
- Aaargh20318 4y agoSure, but unlike PV "The construction of the ISAAC Solar Icemaker involves only welding, piping and sheet metal work, and there are no expensive materials." So this can be produced and maintained/repaired with much simpler tools, that makes it much more feasible to use in remote area's or developing countries.
- calvinmorrison 4y agoOr more so that mechanical refrigeration (as opposed to river ice extraction and shipping) may be a small scale technology that could exist past supply chain collapse
- KennyBlanken 4y agoNo expensive materials but it costs $7,000
- tenthirtyam 4y agoIf you find this interesting, then read the book or watch the film "The Mosquito Coast" by Paul Theroux. The whole story is about a fridge such as this operating in the heat of Africa.
- stefantalpalaru 4y ago> The whole story is about a fridge such as this operating in the heat of Africa. In Honduras, Central America: https://en.wikipedia.org/wiki/The_Mosquito_Coast_(novel) https://en.wikipedia.org/wiki/The_Mosquito_Coast_(novel)
- abrax3141 4y agoI thought that was run on hydrogen, which would be a nightmare for many reasons. Pure solar (either PV or direct heating) seems like it’s way simpler, if slightly less efficient.
- jakedata 4y agoMy non-electric refrigerator operates along similar lines but uses a propane burner to dissociate ammonia from water in a continuous cycle. Devices such as this can operate on many different heat sources including kerosine. Absorption refrigerators have been available for over a century but they are neither cheap nor inherently safe. https://en.wikipedia.org/wiki/Absorption_refrigerator#Single_pressure_absorption_refrigeration https://en.wikipedia.org/wiki/Absorption_refrigerator#Single... My next off-grid refrigerator will be solar-electric with a high efficiency compressor. Even factoring in the cost of additional solar panels and a storage battery it will be cheaper to purchase and certainly cheaper to run.
- nightbrawler 4y agoAt my offgrid cabin I converted a $300 chest freezer to a fridge by using an external thermostat that toggles power off/on based on temp. I have it turn on at 37 degrees and turn off at 35. It uses such little power that it's not even a factor for my small solar setup.
- ilovetux 4y agoChest freezers are great because they dont have a front-facing door which lets all the cold fall right out.
- nightbrawler 4y agoIndeed. Not as easy to organize as one with a front facing door, but we keep stuff organized in milk crates and it's worked great for our family for many years now.
- hinoki 4y agoWhat’s not safe about them? I thought that absorption refrigerators were developed to be safer than existing refrigerators, before non-toxic working fluids were discovered. Einstein-Szilárd fridge. Yes, that Einstein and that Szilárd. https://en.m.wikipedia.org/wiki/Einstein_refrigerator https://en.m.wikipedia.org/wiki/Einstein_refrigerator
- solardev 4y agoChemically/physically, how does this work? What are the inputs and outputs? (edit: n/m, it's not generating ammonia, it's just using it as a coolant)
- netsharc 4y agoThe patent has more detail: https://patents.google.com/patent/US4744224A/en https://patents.google.com/patent/US4744224A/en Input is sun and ammonia, I guess from fertilizer. Or, wait, the ammonia is part of the system and not a consumable.
- solardev 4y agoAh, thank you! I mistakenly thought ammonia was produced from the process somehow. It's not, it's just used in a closed loop as a refrigerant.