Cooling from the sun?

Yes. Refer to the following website for more information:

https://www.cibse.org/getmedia/5c9a9e15-5103-4b70-8aa1-1b7456fdf9a5/Datasheet-7-Absorption-Cooling.pdf.aspx

Yes something similar in idea to a powerstation cooling tower.

The simplist solar cooling is done with a solar chimney pulling the hot air out of the attic and upper floor. All the solar chimney amounts to is a vertical box with glass on the south side,inlet on bottom ,outlet on top(you can outfit the top with a vent turbine). As the air in the chimney heats up it rises drawing in air from below. keep all the windows closed in the house except for one in the basement. By drawing the (cooler) basement air thru the house you cool the place down for free. This system can also be augmented with cool tubes burried in your yard (don't know if you want to go to that extreem. Look up solar chimney and cool tubes on the internet. If you want to use an evaporator, that could go in the basement and cool the air being drawn in by the solar chimney.

This is a good idea for those of us in west Texas. You could put an evaporative cooler pad in each open window.

Why use electricity to move recirculated air over the evaporator? A small Stirling engine powered by the sun would make the unit independant of electricity from a grid! For years I have been telling people that the peoples of Africa can have clean water and power by using a simple Stirling engine combined with a solar collector, but nobody is listening!!! Spencer.

People don't listen to what you say, they listen to what you do. Make one and you'll be a hero!

Hi billb. Here is some news for you. I designed and constructed several types of Stirling engines over the years but to set them into production on a large scale takes a huge amount of money. I demonstrated these engines to several people in industry via various expositions, but nobody was interested, I was told that the problem was that we have oil! Another thing was that people just wanted to invest in high tech engines, but that is the wrong way to go about it as the Africans just need low tech as long as it works. Remember, any efficiancy is good enough if one does not have to pay for fuel! Spencer.

My limited knowledge of the Stirling cycle is to extract mechanical energy from heat energy by cooling. The engines that I have played with displace hot air into a cold chamber and the a vacum that is formed allows atmospheric pressure to drive a piston.

Dosen't this require a source of cool air or water that will be heated by transfer. We now have mechanical energy at the cost of heating water or air.

Don't we still need a mechanical refrigeration cycle of some sort.

If we already have a source of cool air or water, why are we heating it.

Also how do we concentrate Solar energy on the Engine to make it run?

Try to google a bit on these heat engines.

This is an interesting website: http://stirlingenergy.com/solar_overview.htm

Hi Snakes, You are not quite right I'm afraid. The gas inside a stirling engine is heated causing it to expand, this is what drives the working piston. Spencer.

The Stirling engine that I worked with was made in the early 1920s. There was a water well on a farm in upper New York State that also had natural gas bubbling up. The well was capped and the natural gas was collected and burned beneath a cylinder, heating the entire cylinder. A second cylinder (the power cylinder) along side was cooled by a water jacket with cold water from the well. There was a complicated displacement mechanism (a round sealed cylinder) attached to the crank that went down in the hot air cylinder and forced the hot air into the cold cylinder. Cooling the hot air in the cold power cylinder caused a vacuum and atmospheric pressure forced the piston down into the cylinder and turned the crank. Also attached to the crank was also a cylinder that pumped the water from the well that cooled the cylinder. The water was the run to a trough for the livestock to drink.

Note. On the power stroke, the piston went DOWN INTO the cylinder. There was a vaccum in the cylinder and atmospheric pressure forced it in.

Today is my birthday and I am 80 years old. This engine was still running in the 40's when, as a young boy, maintained it. (light the gas burner each day for water)

Hi Snakers. The engine that you are describing is an Ericcson engine, also known as an atmospheric engine. Solar power of phoenix make a small model of this engine called The flame Eater. This is not, strictly speaking a stirling engine. Spencer.

Hi Scapolie...

You are correct. I now remember the Ericcson name cast into the side on the engine.. At least somebody knows what I am talking about. Local people talked of it as a Stirling but probably heard the name and coined it for this engine. As I remember, the pistons had leathers for seals and were quite trouble some.

Thanks for the info.

Hi Scapolie, You are not quite right I'm afraid. (to use your own words...!)

The gas needs to be both heated and cooled to power the Stirling engine. Generally one cylinder is heated and the other is either cooler or cooled....

Check out this animation for a 2 cylinder Stirling engine:-

http://www.keveney.com/Vstirling.html

There are a host of other engine types at :-

http://www.keveney.com/Engines.html

Spencer,

Do you have any information on the engines you built? I saw your other note and will write you off line to talk about that.

I know lots of investors and they are all the same. It's all about money and risk. I can only assume that if investors didn't bite when you demonstrated it, they weren't convinced it would make them enough money to compensate them for whatever risk they perceived, even if they believed it worked. Your opinions would mean nothing to them, just their own analysis of risk vs. reward. I doubt they are interested in helping the Africans or anyone else for that matter, unless they perceive that by doing so they get a sufficient return.

I'd be interested in knowing more. I'm interested in taking my house off the grid as a demonstration project, even if it's just for a short time, and am looking for practical ways to do that, even if it's with prototypes of stuff I have to build myself. Your last sentence about zero fuel cost wouldn't fly for any investor. Fuel is only one component of cost. Capital cost, land, maintenance, insurance, depreciation etc, etc. are all still there and those alone can make a project unattractive, even with zero fuel cost. Nobody would buy a car that ran on air if it cost a billion dollars to buy!
Bill
Atlanta, GA where it hit 100 degrees F today

I would love to here more about your Stirling Engines. Your right that no one wants to back this little work horse. Can you tell us more about your design? Like how do you get it to work with solar? I have read that you need a 300F degree differental to get any real work out of these engines. I can see easily getting around the 70F mark on the cold side so how to you get to 370F on the hot side. Can you get to those temps with a solar furnace? I have read you can lower the differental with a large displacement engine, are you using something like that?

Like I said I would love to hear what you have to say about these machines. Would there be any way I could keep in touch with you? I really think there is such a future for these wonderful machines if we could only get someone to mass product them. Do you think it would be possilbe to make them out of simple house hold materials.

Hi fishpipes. No you cannot build a stirling engine of any power from simple house hold materials. You can contact me via my email address: garnets@blueyonder.co.uk I will be only too pleased to hear from you. Spencer.

Check this link:-

http://www.keveney.com/Engines.html

The really old refigerators (invented by Dr. Funkhauser at the University of Kentucky) used a heat source to drive the cooling effect of the refigerator. This was done using ammonia as a refigerant instead of freon. The bad thing is that it would not work unless there was enough heat generated. The good thing is that the hotter it got the better it would perform. I'm thinking about tinkering with the same idea for my garage, along with solar panels and batteries for electricity (just for my garage, until I can get the bugs worked out.)

I would like to add my questions:

1. There are well-known diagrams of PV (photo-voltaic) source of DC energy + A/C (air conditioner) driven also by heat pump. It is somehow complicated scheme. But it can fulfill needs in electric grid black-out time. Is any simpler solution for small houses that could have direct produced electricity arranged to run a simple heat pump / small DC motor said 12 or 24 V?

2. Where to find ready to use solar powered refrigerator?

I always thought it would be cool (pun intended) to use a Stirling engine turning a smaller Stirling cryocooler. Use the cold side of the cryocooler to cool some circulating chill water...just a fun idea, nothing serious.

try http:sleekfreak.ath.cx:81/3wdev/VITAHTML/SUBLEV/EN1/ for technical papers on stirling configurations for cooling william beale and VITA

This is a great link

(same as above but clickable)

Solar Chimney: Be vewy, vewy careful about pulling the cool air out of the basement especially if you live in a humid environment. Yes, the basement is a heat sink but when you pull the cool air out of the basement, you replace it with warm humid air from the outside. Water will condense on all the cool surfaces in the basement and you will grow mold and mildew like you never thought possible. Sure, solar is attractive because the energy is "free", but the equipment to harness it is far from free. I think you would find the size of a collector to make a useful absorbtion cooling device will dwarf your house. The witch's brew of ammonia and other chemicals in these propane fridges are also prone to limit the life of these devices. I've heard ten years is about the average life of the fridge, whether its used or not. I have one in my travel trailer and it works great, cooling my freezer section to below zero F (-17C) but it does not have a high heat capacity like an electric compressor refrigerator. It works best if it gets loaded with already frozen items. Be-dee, Be-dee, that's all folks.

Here's a different approach you may find useful -

http://www.solarmirror.com/fom/fom-serve/cache/30.html

It's based on night sky radiation.

Thanks for all the suggestions and support to my original question. JR PECK (#6) and BRAVE SIR ROBIN (#16) seem to share my exact concerns best. When I open the door of my travel trailer refrigerator the small amount of propane used to cool the refrigerator does not cool the entire trailer. Does anyone know if a mirror lined satellite size dish focused on a refrigerant line to an absorbtion (or adsorbtion) system would provide enough heat for a viable air conditioner. I believe the tracking/panning problem of keeping the dish pointed at the sun is minor.

In space cooling is done through radiation, and heating is done the same way.

A cooling systems has a radiator that is kept in the shade, it can radiate the excess heat into deep space, important is to keep it in the shade, the sun's radiation would heat it up enormously rapid.

The problem is to regulate the system: to keep your electronics in the area where they have the longest life expectancy.

The idea of pointing a mirror to a heat absorber is used with Sterling generators, but can only be used in close solar orbits, there where the life expectancy of other systems is also OK.