Solar cooling anyone?
LoopyByteloose
Posts: 12,537
Being in Taiwan, the last thing I need is solar heating. But there are old patents from the 1890s that actually made ice with solar heating of ammonia gas. The unit is huge and the cooling cycle is once a day. But it does indeed make block ice.
Taking this a step further, there are butane-powered refrigerators that do quite nicely in modern RVs and were popular in homes in the 1920s.
So I am wondering if one can actually make a solar air conditioner. Having a microcomputer involved may make this doable. One could use the principals of the butane refrigerator to increase the cooling cycles. One could use water converted to ice or even salt water [noparse][[/noparse]as an enhancement] to store cooling for later needs during peak periods.
What one really needs is to see if a 10,000BTU sustained cooing output is feasible. This is the average capacity of a small modern a/c unit. Of course, I would assume you could use all the electric fans you require for distribution of the cool air. This isn't a Fred Flintstone kind of concept. I suspect that there is a definite market for augmenting conventional a/c with solar power. After all, in Taiwan many people pay summer cooling electric bills that are equivalent to U.S. winter heating bills.
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan
Post Edited (Kramer) : 9/7/2008 4:44:12 PM GMT
Taking this a step further, there are butane-powered refrigerators that do quite nicely in modern RVs and were popular in homes in the 1920s.
So I am wondering if one can actually make a solar air conditioner. Having a microcomputer involved may make this doable. One could use the principals of the butane refrigerator to increase the cooling cycles. One could use water converted to ice or even salt water [noparse][[/noparse]as an enhancement] to store cooling for later needs during peak periods.
What one really needs is to see if a 10,000BTU sustained cooing output is feasible. This is the average capacity of a small modern a/c unit. Of course, I would assume you could use all the electric fans you require for distribution of the cool air. This isn't a Fred Flintstone kind of concept. I suspect that there is a definite market for augmenting conventional a/c with solar power. After all, in Taiwan many people pay summer cooling electric bills that are equivalent to U.S. winter heating bills.
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan
Post Edited (Kramer) : 9/7/2008 4:44:12 PM GMT
Comments
Although I have worked in manufacturing AC's years ago, mostly on the controller side, here's what comes to mind: Obviously butane is questionable as it is explosive, and ammonia gas is highly corrosive. Freon and it's enviro-friendly substitues are highly compressible. Compression and expansion is what you need - or, alternatively, a fluid that carries heat well. In Florida, we often use well water straight out of the ground which then circulates through a coiled heat exchanger. The compressor / heat exchanger is actually inside the air handler, whereas 'regular' AC's have the compressor (or heat pump) unit outside. The heated water is then merely dumped back onto the ground, to trickle eventually back into the well.
Since you've got us thinking outside the (AC) box anyway...
Water is an excellent heat carrier...
Wondering if a solar water heater could be made to run in reverse?
cheers, and with a fan on my desk
~~ Howard in Florida ~~
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Buzz Whirr Click Repeat
Maybe there are butane refrigerators, I don't know, but propane refrigerators are popular items in Hawaii.· The peril isn't the flammable gas, as such, but carbon monoxide build-up (the result of poor maintenance.)
Post Edit -- butane is used in the Einstein refrigerator (yep, that Einstein.)
Post Edited (PJ Allen) : 9/7/2008 1:14:46 AM GMT
These are wonderful refrigerators without any moving parts that just silently plug along for years and years. The real question is can this be scaled up to cool a room? And can microcontrollers with appropriate sensors and such enhance the design enough to bring this to be a viable commercial product?
I have had this on a back burner for 15 or so years, but sudden everyone is worrying about global warming. Obviously I am not going to bring a product to market. So it is really up to anyone that wants to meet the challenge and they are welcome to research and patent whatever they can.
In sum, I just think that we are wasting huge amount of electricity on cooling when there is nearly always available solar energy in this context.
Some homes already have 'heat pumps' that draw in heat in the winter and output heat in summer. So I suspect with the right configuration, solar energy can at least drive the compression in some situations.
Should we make this a contest?
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan
Post Edited (Kramer) : 9/7/2008 4:47:24 PM GMT
http://www.solarpanelsplus.com/solar-air-conditioning/
Don't know how much it costs and what the payback time would be, but at least one company is selling the units.
Yazaki Taiwan has headquarters in nearby Pingtung and employs 690 people. I guess I've not discovered anything new.
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan
Post Edited (Kramer) : 9/10/2008 7:14:00 AM GMT
We have the same thinking. But I was thinking for a small place like car and use peltier as cooler.Here in my place the the temperature is around 32C - 34C. And If you park your car on sunny day the temperature inside the car could reach 70C - 80C.
It's happen in my place where a mum accidentally leave her daughter in her car found out the girl has died because of overheating.
It's not to make the car so cool but at least the temperature is equal to outside temp.
The solar panel can be put on the roof and use small fan for distribution of the air inside the car.It can save your gas in traffic jam too.Oil price is high now.
What do you think?
Due to basic Heat-Pump principles, the Lamina Flow or thermo-acoustic Stirling Engine is supposed to get very cold on the "closed end" of the test tubes shown in the videos below.· Now, I don't think this can be used to make Ice, but it could be a form of usable "Solar Cooling" from a not so obvious source.·
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http://www.truveo.com/Lamina-Flow-Stirling-Engine/id/3655485202
http://video.aol.com/video-detail/twin-cylinder-thermo-acoustic-stirling-engine-1/2992158273
·
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
As usual, you bring something interesting to consider. As I now see it there are really two different devices to be considered.
One is a solar driven pump of some sort that would enhance the flow of coolant - increase the number of overall cooling cycles. This might focus on some sort of Stirling engine in a pumping role.
The second is enhancements to how the heat is exchanged and dumped. This is where the absorptive refrigeration really begins to be useful.
Put them together and one might be able to have something wonderful.
Regarding leaving an infant in a car, I suspect the best thing would be an alarm and automated roll down of the windows. Waiting for solar cooling might just be too slow. And would people install it for these reasons?
Sadly, most adults that have been caught in these situations of forgetting a child in a car appear to be boozers and druggies that stop in for a quickie and just get too loaded to watch the time. As it is now, the courts usually press an manslaughter conviction and that seems to be really the best device to get people's attention. Never leave an infant unattended in car regardless of weather, they need constant care and attention.
Not everything can be solved with a gadget.
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan
Another interesting device is the "Helmoltz Resonator" ... www.music.mcgill.ca/~gary/307/week9/node3.html ... Which basically is the same reverberation effect the thermo-acoustic Stirling Engine provides only you don't need the sun. In other words, with "SOUND" you could produce the same heating and cooling effect.
www.mecheng.adelaide.edu.au/anvc/thermoacoustics/index.php?option=com_content&task=view&id=6&Itemid=2
www.acoustics.org/press/147th/thermoacoustics.htm
www.abc.net.au/science/news/stories/s741401.htm
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
On the other hand, inside a steel mill or in a toll booth on a freeway this might be a future prospect.
The key point is that there are cooling alternative technologies and most of the DIYers have ignored the greater potential for making a few bucks with these. Of course there are gigantic companies that make all their income from cooling alone, but it would be wonderful to find applications for the 3rd world. It is nearly always 85 degrees here and in India the poor are being scorched by 120 degrees at times.
So I am thinking terms of cooling dwellings rather than computers or autos.
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan
On the other hand, inside a steel mill or in a toll booth on a freeway this might be a future prospect.
The key point is that there are cooling alternative technologies and most of the DIYers have ignored the greater potential for making a few bucks with these. Of course there are gigantic companies that make all their income from cooling alone, but it would be wonderful to find applications for the 3rd world. It is nearly always 85 degrees here and in India the poor are being scorched by 120 degrees at times.
So I am thinking terms of cooling dwellings rather than computers or autos.
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan
We had one of those ammonia plants in the town I grew up in. Quite dangerous. Killed a couple of workers over the years (our OSH laws were slack)
Slightly off the topic, I did some compulsory military service in South West Africa (now Namibia). My radio position was high up in the Brandenburg Mountains (desert) where the daytime temperature rose to 50+ Deg C. At night, it dropped below Zero. The air was very dry.
We covered our radio tent with many layers of hessian which was widely used in the desert as camouflage. We then sprayed it with water whenever it became dry which, by 2pm was every 15 minutes. The evaporative cooling was quite extraordinary. You could wear your bush jacket inside. (water wasn’t a problem, we got a new tanker every second day)
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http://www.seastead.org/localres/misc-articles/solarice.pdf
Rick
The problem becomes much more difficult when both the temperature and the humidity soar. You no longer get the evaporative cooling effect and one has to have a media other than water provide the evaporative cooling inside a closed loop. That is way we used ammonia, freon, and whatever is now acceptable. These closed loops require a pumping device
And that is why I mentioned using solar energy to create a pump. One can either have create a mechanical pump action of some sort or by creating bubbles in the media, have a percolation pump similar to what is used in a tradition coffee percolator. In fact, the percolation principle was used in 1920s in the natural gas burner refrigerators.
One can do U.S. patent searches for solar 'icemaker' and get the info on the machine I referred to at the beginning. I would think that making ice at the end of the day and then using the ice the next day is a very valid means of solar cooling. Having a heat exchanger just doing cooling now does not iron out the problems of having the cooling whenever you most want it.
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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).
Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan