There is a refrigeration method, in common use in RVs for instance and in industry, that is able to cool things from heat. The idea seems counter-intuitive but the technology has been in use at least as long as electric powered refrigeration.

I would like to do some experiments in the area of solar powered air conditioning and share notes with anyone that is interested.

My basic interest is this: use the solar technolgy that is the most advanced, most used, and least expensive and adapt it for solar air conditioning. The area of solar collectors that fit the bill are solar swimming pool collectors. Today they account for the vast majority of solar collection capacity. The collectors are the least expensive and readily available and simple to work with.

Their limitations as they relate to a system that could be used for refrigeration though, are that they are a low pressure and low temperature system.

The idea I have is to use a system basically using wind power and a vacuum pump to create a tandem system of low temperature and vaccuum to affect the phase changes which are at the heart of refrigeration systems.

Both the wind system vacuum generation and the solar swimming pool collectors are relatively the low tech ends of their prospective technologies. A solar/wind combo air conditioning system would need to adapt existing cooling technology similar to gas powered refrigerators and the Crosley icy Ball refrigeration system to the solar/vacuum system so that it could operate in the low temp/low pressure restraints of the inexpensive solar collector technology.

Very cool idea Wow you have put come thought into this. Even though I am an engineering tech it took me a bit of poking to understand what you were saying. Sounds like essentially using ammonia cycle refrigeration (as you pointed out used in RV's) which is essentially the Crosley Icy Ball refrigeration.

correct me if I am wrong but the ammonia cycle or gas-absorption refrigeration techniques basically works like the Crosley Icy Ball refrigerator http://en.wikipedia.org/wiki/Icyball by having a cold side and a hot side of a system. The liquid ammonia sitting on the cold side begins to be absorbed, through evaporation, by the water on the hot side. The evaporation of course causes extreme cooling, to about 19 degrees Fahrenheit (easily cold enough to freeze water) which can be harnessed for air conditioning pumping it perhaps through an existing central air system. Then when the ammonia completely evaporates and is absorbed into the water side heat (as in that from solar) is used to separate the separates the ammonia from the water which puts the ammonia back to the cold side to start all over again.

I see what you’re saying, if you used an existing unit designed for RV’s and existing solar/vacuum heating unit (rooftop home heating or pool water heating) and put them together you could have something here. The small amounts of vacuum could be maintained by a pump that would use just a trickle of electricity (I would think) perhaps by wind or a small solar electric setup.

Very cool idea…I am eager to see what you find in regards to existing, and affordable, setups such as that of the RV gas-absorption refrigerator.

You an engineering tech huh! Just who I ned to bounce these ideas off of. It was quite refreshing to see my ideas are on track. The limit of my engineering background is some training in the enthalpy chrts and theory in an ag engineering course.

That knowledge of enthalpy (dewpoints, boiling points, saturation points, releative humidty etc for the novice reader) gave me some basis for my theory.

You understood exactly what I was saying (that isn't always easy LOL). If we use a low cost, low temperature collector (swimming pools collector) to heat the aquaammonia solution it will absorb the energy but it won't get hot enough to force a phase change (which is where the cooling effect comes from). With an enthalpy chart calculated at different air pressures, however, it can be precisely calculated at what amount of vacuum a lower temperature solution will undergo that phase change.

You figure i would only take a "trickle" of electricity to generate enough vacuum? I don't have a clue and that would be great if that is the case. It would greatly simplify the design, as it could use a simple vacuum pump to operate.

The neat thing about solar powered air conditioning is that it is most readily available in the locations and at the times when it is most in demand. Any system developed would directly save "peak" electricity, the most expensive type.

Hey, take a look at this project http://www.thesietch.org/projects/solarthermalpanel2/index.htm using the heat dispersal radiator off the back of an old refriderator. i am thinking this jsut might work for the heat. I was thinkinag a bit that putting a couple of these together and piping them into your exisint hot water heat sytem might work too. What if you used a coil of copper tube and winded it around your intake into your furnace hot water inlet copper pipe?? Might not heat it up a ton but maybe half way so that the furnace doesnt have to wrok so hard?? not sure how my furnace operates so I'd have to take a look into this closer...Interesting idea though...