I'm looking for people who would be interested in a solar powered heat pump for their home. This would work similar to a conventional heat pump, heating the house in winter and cooling the house in summer, except that it would be powered from solar collectors (not photovoltaics) and consume no (or almost no) electricity. The patents on this technology expired a long time ago, but for a variety of reasons, units are not being commercially manufactured.
I'm not interested in trying to set up a manufacturing concern to commercially market mass produced units (yet). This would be more like an architectural feature built onto the house (or added later) that would significantly cut winter heating and summer cooling needs.
If you enjoy tinkering with your home's HVAC system and would like to try to revive this technology, please leave a reply to this post. If you are an HVAC contractor and would like to add a new technology to your list of services, I would also like to hear from you.

What is the technology of the equipment? You've got my interest........

John

The best reference I can give is to the patent Albert Einstein got for an absorption refrigerator. A Wikipedia article is at this link: http://en.wikipedia.org/wiki/Einstein_refrigerator and it has a link to the original 1930 patent.

An analysis was done 10 years ago, which is at this link: http://www.me.gatech.edu/energy/andy_phd/index.html
but aside from a prototype, this did not result in any useful devices being manufactured.

At this time, there is a small market for absorption refrigerators for RVs and off-grid applications, but I have not seen where anyone has developed this technology into a heat pump for a building. I have done some rough calculations about the size of such a system, but I need to get some experimental data to feel confident about the performance parameters of such a system.

As far as cost goes, I think a unit for a small house could be made for under $1000. The components; solar collector, tubing, condensation vessel, duct work, and air handlers are all easily obtainable items and charging the system with the refrigerants is not technically challenging.

I am having a demonstration model with a collector area of .25 sq. m. fabricated (about 20"x20") and I am drawing up plans to put one on the roof of my house. If you know your seasonal heating and cooling needs, I can work up an estimate of the size of a system you would need.

I have long wanted to do something like this. But mainly as a "dump" load for excess summer solar hotwater production.

Temperatures will be the limiting factor. Absorption chiller need very hot water. http://en.wikipedia.org/wiki/Absorption_heat_pump

Then you have Adsorption chillers and Absorption chillers.

http://en.wikipedia.org/wiki/Evacuat...hermal_cooling

What is the typical output of an Evacuated tube collector?

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Making the world a better place just makes sense.

Since this is the process of ammonia going in and out of aqueous solution, it would be better to call it solution and evaporation, but the basic principle is the same -- collected solar energy causes evaporation or desorption, and the reverse process occurs in the condenser/absorber at a lower temperature.

The system I have been studying has the solar collector at around 90C, the cold reservoir at 0C, with the heat from both of these rejected at about 45C, which is possible in all but the hottest areas of the desert southwest.

Still have my interest.......

I am familiar with the Arkla Servell absorption chillers in production from the 70's using natural gas.

Are there any differences on the system you are using for solar? Is it chilled water or DX? What is the evaporation temperature of this particular system?

I have some rv refrigerators I was doing some playing with, yes you can get cold from the sun, collect it, reflect it, and get cold, scale the system up enough, and I am sure it will cool a home. Providing your home has the correct view of the sun, and what not.

This is one parameter that can be adjusted by varying the composition of the co-refrigerant of the ammonia. More propane in the mix would lower the evaporation temperature, and adding pentane isomers to the mix would raise it. I will try for a temperature around 40-45F so that there won't be ice buildup on the cooling surfaces.
I want to stay away from having chilled water loops in the system, as that would add little benefit, but a lot of complexity.

40 deg F evaporation with a fin and tube coil sounds like a good goal. Chilled water loops for residential does equal more problems but also is for safety. If the coil has a leak, are we talking about ammonia and lithium bromide mixture in the conditioned airstream? Not something I want to breathe. The chilled water loop protects the inhabitants of the residence if the evaporator has a leak. Just me thinking out loud.........

Harpo:
Yes I am interested. There are a few commercial untis out there, but too large for residential applications. The good news is that there are residential size units coming soon: the most likely is by Kingspan Solar, but not yet.
Also, do you know of any small heat pumps which run directly off rotating power: bicycle, engine, wind, ...
I am considering a vertical axis wind turbine to power a ground source heat pump.
Solar-heated water from evacuated tubes can get as hot as 130 F.

IMO, wind and solar mostly complement each other.
Please let me know your thoughts.