Intersting new product, sun powered AC

[Rob Beckers]

Time Magazine had an interesting article about a new company in Sweden, named Climatewell, that makes solar powered air-conditioners. Looks like they are using salt and water in a vacuum as a chemical heat-pump. It's billed as an air-conditioner, but my (very limited) understanding is that it will heat too. The interesting part is that there's no compressor, as in a conventional heat-pump or AC unit, instead the only thing that uses electricity is a small pump to circulate water. In theory this could be very, very efficient! It reminds me a bit of the solar powered AC units that use ammonia (and those are just like the propane powered fridges, but using solar instead of propane to make an AC unit). Their Web site is:

http://www.climatewell.com/

I thought I'd mention it here. Comments are of course very welcome.

-Rob-

[James Jarrett]

I think I have a problem with this. Yes it's neat, and it may be practical, but I have always been a fan of KISS, as such, the idea of a solar *HEATER* seems a bit silly *UNLESS* you already have solar water heating and are using that same water to heat the house.

Solar cooling is nice, but Again, if you have a ground loop (water again) system, then you need very little cooling.

If your house is well insulated, a simple water loop that goes around your house three or four times burried at least 6 feet down, will give you water that is 55 degrees +- year round.

In the summer, you run that water directly through your "in floor" heating elements and it will bring the temperature down in your house dramaticly, and quietly.

In Winter, you take that water and run it through a series of solar boosters and you have all your heat as long as the sun shines a good bit each day.

True, for this to work yoiu need to have a VERY heavy slab that is isolated from ground temp, but this is not so hard to manage.

With a rig like this, a very small commercial grade chiller unit could keep the house quite cool, and a small gas on demand water heater handle all your heating.

That just seems like a better, and more reliable (and probably cheaper) way to do it.

Now if you are retrofitting.... Then maybe the new unit is better.

[James Fromer]

I would be interested to learn more about the looping method you described M.r Jarret as I have been attempting to design my next home with green as the theme. I know that "air" conditioning (both with heat or cooling) is very inefficient. a better more efficent (and perhaps cheaper method) seems to be what you described. Is there somthing you can point me to to learn more about what it is you were talking about. or is there more you can tell me/the community on this subject?

[Rob Beckers]

I suppose it also depends on the climate you live in. Solar heating ground water wouldn't cut it for heating here in the winter. I've been looking at replacing the gas furnace with one of the newer heat pumps, used with a ground-water loop. They've gotten very efficient, 400% for heating!

Before the gas furnace (and before I lived here) the entire neighborhood was using first-generation heat pumps for heating and cooling. They worked very poorly, in effect one was heating the house electrically (expensive!) in winter. So as soon as natural gas lines were put into the ground, around 8 years ago, everyone here switched to gas furnaces.

Because of the earlier heat pumps, all the houses around here still have two wells available. One for pumping water out (now used for drinking water), and another one for pumping back the return water of the heat pump (now unused). So it would be relatively cheap to change back again to a heat pump. The same heat pump would also provide cooling in summer, the little bit of it that we need. I have to talk to a couple a few houses down that did just that about a year ago and see how their gas/electricity bills stack up, before and after.

-Rob-

[John Allen]

The Climatewell product looks very interesting to me. Do Any of you have experience with Lithium Cloride salt for thermal storage?

John Allen

[Chuck Patenaude]

although I have played with glaubers salt, for pricing though, I tend to end up back at water, or granite in a water matrix...always thought the metal hydrides would be an interesting approach for higher temp systems, but then you have the problem of pressurized gas storage.

[John Allen]

I also lean toward water for cost reasons. How much insulation do you use?

[Lion Kuntz]

Time Magazine had an interesting article about a new company in Sweden, named Climatewell, that makes solar powered air-conditioners.

They're too late.

http://h2-pv.us/wiki/tiki-index.php?page=4161211
International Harvester invented this in 1979. The patent has been expired for about 13 years now.

United States Patent 4,161,211
Duffy , et al. July 17, 1979
Methods of and apparatus for energy storage and utilization

Abstract

Methods of and apparatus for providing refrigeration, heating and air conditioning which use metallic hydrides for thermal energy storage and upgrading.
Inventors: Duffy; Thomas E. (San Diego, CA), Rohy; David A. (San Diego, CA)
Assignee: International Harvester Company (Chicago, IL)
Appl. No.: 05/753,821
Filed: December 23, 1976



About 8 years later geopolymers were invented, which is also expired. That replaces the stainless steel holding tank with cheap mineral plastics made of potter's clay and a strong alkaline activator.