Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
The Navaho made ice but the holes they opened to the night sky were entered by ladder. They were deep as I remember, more than 20 feet. I believe this solved the air warmth problem. Guag Meister [EMAIL PROTECTED] wrote:Hi Joe and All ; Yes this is exactly right. Thank you. I did some searching. There are some web pages on this which I found. The problem with getting significant cooling using a normal solar panel is that normally a solar panel is designed to absorb the energy of the solar spectrum (lots of visible and UV, some IR). Then it must also be designed to prevent re-radiation of the IR due to black body. This is mostly accomplished by putting a piece of glass over the absorber. Glass traps the black body IR inside the panel (it also lowers conduction losses significantly). The absorber by itself is a good radiator, but a properly designed solar panel will trap the black body radiation being radiated from the absorber. So a good solar panel is generally a poor radiator. Kind of like a hot car in the summer sun with the windows closed. The web page I found said the guy had to remove the glass from a simple box collector to make ice. This then exposes the forming ice to the atmospere (and heat). The mans's conclusion was that you could make ice but only on a very cold (a few degrees above freezing)clear night and in still air . This makes sense. Ice formed inside the box collector even when water ouside did not freeze. So apparently there was some cooling going on. Possible that further research could provide materials which can pass IR and at the same time be a good insulator. In Kim's case using a parabolic reflector, the forming ice is in contact with the air. Objects at temperatures around freezing are not radiating much black body radiation. The cooling effect would be swamped by the conduction heat gain from the air. This arrangement could only support a few degrees temperature difference. Some more experiments with temperature tracking inside and outside the reflector, humidity, cloud cover, wind speed, would certainly be worthwhile. Best Regards, Peter G. Thailand __ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ - Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages! ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Hi All, Check out ice caves on the web. There are many in the US and probably around the world. They are natural north facing holes with the correct angle and moisture conditions to have ice in them all year around. By adding a little intelligence to the design and proper doors that shut at the right times you could have your ownMaxwell's demon could work for a cool room, even in Texas. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Hi Joe and All ; Yes this is exactly right. Thank you. I did some searching. There are some web pages on this which I found. The problem with getting significant cooling using a normal solar panel is that normally a solar panel is designed to absorb the energy of the solar spectrum (lots of visible and UV, some IR). Then it must also be designed to prevent re-radiation of the IR due to black body. This is mostly accomplished by putting a piece of glass over the absorber. Glass traps the black body IR inside the panel (it also lowers conduction losses significantly). The absorber by itself is a good radiator, but a properly designed solar panel will trap the black body radiation being radiated from the absorber. So a good solar panel is generally a poor radiator. Kind of like a hot car in the summer sun with the windows closed. The web page I found said the guy had to remove the glass from a simple box collector to make ice. This then exposes the forming ice to the atmospere (and heat). The mans's conclusion was that you could make ice but only on a very cold (a few degrees above freezing)clear night and in still air . This makes sense. Ice formed inside the box collector even when water ouside did not freeze. So apparently there was some cooling going on. Possible that further research could provide materials which can pass IR and at the same time be a good insulator. In Kim's case using a parabolic reflector, the forming ice is in contact with the air. Objects at temperatures around freezing are not radiating much black body radiation. The cooling effect would be swamped by the conduction heat gain from the air. This arrangement could only support a few degrees temperature difference. Some more experiments with temperature tracking inside and outside the reflector, humidity, cloud cover, wind speed, would certainly be worthwhile. Best Regards, Peter G. Thailand __ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Hi, Interesting; another post said the Egyptians form ice at night, by ice forming do you mean the water froze into block of ice? I would guess that a bit of ice forming may suggest that it may be possible to transfer the heat in a cool room to the night time sky. Are there any practical example of this have been done or being done? The post mentioning the Egyptians on mentioned that they made ice by radiating heat to the night time sky, but there was indication how they went about it. Thanks Doug - Original Message - From: Kim Garth Travis [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, September 17, 2004 6:04 AM Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - solar. : Greetings, : Actually I have put a bottle of water in my solar funnel cooker and left it : out at night when the temperature was in the 50F and had ice form. It will : only do it for me on a real clear night, it does not work on a cloudy night. : Bright Blessings, : Kim : : At 05:12 PM 9/15/2004, you wrote: : Hi, : : But, to create ice wouldn't that require the night time temperatures to : get to freezing? Even if the goal was to cool a heat sink, power is still : would be required. : Doug : : - Original Message - : From: [EMAIL PROTECTED] : To: [EMAIL PROTECTED] : Sent: Tuesday, September 14, 2004 11:47 AM : Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - : solar. : : : : : : : : : : : : Greetings to all. : : : : A new member here. : : : : If you have clear skies at night most of the time, solar panels can be : used in reverse to radiate heat all night long. Circulate anti freeze from : them : : to your block of ice during the night and use the ice in the usual way. : Not shure how much heat you can get rid of in this way. A calculation or : : experiment is in order. The panels could be used for heat gain during the : day in their usual way. Mount on top of your dirt mound for shade. : : : : : : ___ : : Biofuel mailing list : : [EMAIL PROTECTED] : : http://wwia.org/mailman/listinfo.cgi/biofuel : : : : Biofuel at Journey to Forever: : : http://journeytoforever.org/biofuel.html : : : : Biofuel archives at Infoarchive.net (searchable): : : http://infoarchive.net/sgroup/biofuel/ : : : --- : Outgoing mail is certified Virus Free. : Checked by AVG anti-virus system (http://www.grisoft.com). : Version: 6.0.754 / Virus Database: 504 - Release Date: 09/06/2004 : : ___ : Biofuel mailing list : [EMAIL PROTECTED] : http://wwia.org/mailman/listinfo.cgi/biofuel : : Biofuel at Journey to Forever: : http://journeytoforever.org/biofuel.html : : Biofuel archives at Infoarchive.net (searchable): : http://infoarchive.net/sgroup/biofuel/ : : ___ : Biofuel mailing list : [EMAIL PROTECTED] : http://wwia.org/mailman/listinfo.cgi/biofuel : : Biofuel at Journey to Forever: : http://journeytoforever.org/biofuel.html : : Biofuel archives at Infoarchive.net (searchable): : http://infoarchive.net/sgroup/biofuel/ --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.766 / Virus Database: 513 - Release Date: 09/17/2004 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
In old times in Iran, radiation from an enclosure to the night sky was used to accomplish local cooling to produce ice for special purposes, like the emperor's sherbets. An article in Scientific American years ago described this. This technique needs *dry* air which will not absorb infrared radiation and reradiate it. It cannot be used in humid climates. Doug Woodard St. Catharines, Ontario, Canada On Wed, 15 Sep 2004, Doug Younker wrote: Hi, But, to create ice wouldn't that require the night time temperatures to get to freezing? Even if the goal was to cool a heat sink, power is still would be required. Doug - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, September 14, 2004 11:47 AM Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - solar. : : If you have clear skies at night most of the time, solar panels can be used in reverse to radiate heat all night long. Circulate anti freeze from them : to your block of ice during the night and use the ice in the usual way. Not shure how much heat you can get rid of in this way. A calculation or : experiment is in order. The panels could be used for heat gain during the day in their usual way. Mount on top of your dirt mound for shade. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Actually I have put a bottle of water in my solar funnel cooker and left it out at night when the temperature was in the 50F and had ice form. It will only do it for me on a real clear night, it does not work on a cloudy night. Bright Blessings, Kim At 05:12 PM 9/15/2004, you wrote: Hi, But, to create ice wouldn't that require the night time temperatures to get to freezing? Even if the goal was to cool a heat sink, power is still would be required. Doug - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, September 14, 2004 11:47 AM Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - solar. : : : : : Greetings to all. : : A new member here. : : If you have clear skies at night most of the time, solar panels can be used in reverse to radiate heat all night long. Circulate anti freeze from them : to your block of ice during the night and use the ice in the usual way. Not shure how much heat you can get rid of in this way. A calculation or : experiment is in order. The panels could be used for heat gain during the day in their usual way. Mount on top of your dirt mound for shade. : : : ___ : Biofuel mailing list : [EMAIL PROTECTED] : http://wwia.org/mailman/listinfo.cgi/biofuel : : Biofuel at Journey to Forever: : http://journeytoforever.org/biofuel.html : : Biofuel archives at Infoarchive.net (searchable): : http://infoarchive.net/sgroup/biofuel/ --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.754 / Virus Database: 504 - Release Date: 09/06/2004 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
RE: [Biofuel] Creating a cool room storage in a hot climate - solar.
Actually, ice will from even if the ambient air temp is above freezing. How much above depends on humidity and other sources nearby of radiant heat transfer. RADIANT heat transfer, which is a different process than conductive or convective heat transfer. The ice forms because of radiant heat loss to the super cold reaches of space. The Egyptians knew this, and made ice this way. --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.742 / Virus Database: 495 - Release Date: 8/19/2004 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Hi all, As I understand it, the nighttime sky looks like a 4 degree Kelvin source. (going from memory here) A well designed solar panel is insulated so that the ENERGY goes in and out only by RADIATION from the front and by CONDUCTION to the working fluid. ENERGY that leaves a black body (the solar panel) is balanced by the ENERGY coming to it when at equilibrium. If the panel was in outer space and not facing the sun it would cool down to 4 degrees above absolute zero when there was no heat input from the working fluid. Here on earth the atmosphere reflects heat energy radiated from the earth, back to the earth (the green house effect) so a perfect black body at night with a perfectly transparent window and perfect insulation would still not get down to 4 degrees K. But it will defiantly get well below freezing. In fact most solar panels need to be protected from freezing even in the summer.So it will make ice, the question is how much and is it worth the investment. If solar heat is needed during the day, then this would be an added use for the collectors. Air could be the working fluid and the thermal mass of the cool room could be the storage medium (instead of ice) then the system gets simpler. Doug Younker [EMAIL PROTECTED] To: [EMAIL PROTECTED] net cc: Sent by: Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - solar. biofuel-bounces@ wwia.org 09/15/2004 03:12 PM Please respond to biofuel Hi, But, to create ice wouldn't that require the night time temperatures to get to freezing? Even if the goal was to cool a heat sink, power is still would be required. Doug - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, September 14, 2004 11:47 AM Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - solar. : : : : : Greetings to all. : : A new member here. : : If you have clear skies at night most of the time, solar panels can be used in reverse to radiate heat all night long. Circulate anti freeze from them : to your block of ice during the night and use the ice in the usual way. Not shure how much heat you can get rid of in this way. A calculation or : experiment is in order. The panels could be used for heat gain during the day in their usual way. Mount on top of your dirt mound for shade. : : : ___ : Biofuel mailing list : [EMAIL PROTECTED] : http://wwia.org/mailman/listinfo.cgi/biofuel : : Biofuel at Journey to Forever: : http://journeytoforever.org/biofuel.html : : Biofuel archives at Infoarchive.net (searchable): : http://infoarchive.net/sgroup/biofuel/ --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.754 / Virus Database: 504 - Release Date: 09/06/2004 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Hi, But, to create ice wouldn't that require the night time temperatures to get to freezing? Even if the goal was to cool a heat sink, power is still would be required. Doug - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, September 14, 2004 11:47 AM Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - solar. : : : : : Greetings to all. : : A new member here. : : If you have clear skies at night most of the time, solar panels can be used in reverse to radiate heat all night long. Circulate anti freeze from them : to your block of ice during the night and use the ice in the usual way. Not shure how much heat you can get rid of in this way. A calculation or : experiment is in order. The panels could be used for heat gain during the day in their usual way. Mount on top of your dirt mound for shade. : : : ___ : Biofuel mailing list : [EMAIL PROTECTED] : http://wwia.org/mailman/listinfo.cgi/biofuel : : Biofuel at Journey to Forever: : http://journeytoforever.org/biofuel.html : : Biofuel archives at Infoarchive.net (searchable): : http://infoarchive.net/sgroup/biofuel/ --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.754 / Virus Database: 504 - Release Date: 09/06/2004 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Greetings to all. A new member here. If you have clear skies at night most of the time, solar panels can be used in reverse to radiate heat all night long. Circulate anti freeze from them to your block of ice during the night and use the ice in the usual way. Not shure how much heat you can get rid of in this way. A calculation or experiment is in order. The panels could be used for heat gain during the day in their usual way. Mount on top of your dirt mound for shade. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Yours is a bit more tricky, although you might have enough wind ( maybe water power? ) to do the job energy wise. I spent 18 months, just outside of Portland OR, and that was some of the weirdest weather I have ever seen. 3-4 months of total cloud cover, and 2-3 months nothing but sun, and everything else is some where in-between. I remember a trip through SeaTac airport. On the ground the visibility was 50ft. or less, OTOH 75-100 ft into the air, the visibility was over 2 miles. I would hazard a guess that the water table is high there as well, but, not near as warm ( probably allot cooler ), digging in a container of some sort and burying it would most likely work. Greg H. - Original Message - From: George Page [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sunday, September 12, 2004 13:23 Subject: RE: [Biofuel] Creating a cool room storage in a hot climate - solar. I'm really enjoying this discussion on walkin cooler designs. I'm particularly intrigued by the solar cooler idea. I live in an area with poor solar gain, but the climate is temperate, so cooling needs are less drastic. I am needing to build a walk in cooler for my farm. I need the ability to store and cool dairy products safely and adequately. I also need locker cooling for aging meat carcasses, and also short term vegetable storage. Much of the year the demands on the system would be rather low. I live in the Pacific Northwest of the USA. Keep the ideas coming! George George Page www.seabreezefarm.net Vashon Island, WA USA ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
This is what I would say is the best solar cooling / ice maker, I have seen in the longest time ( and I have seen allot of them ), in fact the copy I have, is the same one, and down in Texas, I think it would be the best bet. Add some thermal mass to keep it cool even when the clouds are heavy, and you would have your self a prime solar cooler.I have been thinking of modifying it for house AC ( but local code prohibits the use of anything with ammonia without it being installed by a licensed professional ) Greg H. - Original Message - From: Guag Meister [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Saturday, September 11, 2004 07:02 Subject: Re: [Biofuel] Creating a cool room storage in a hot climate - solar. www.homepower.com/files/solarice.pdf ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
RE: [Biofuel] Creating a cool room storage in a hot climate - solar.
I'm really enjoying this discussion on walkin cooler designs. I'm particularly intrigued by the solar cooler idea. I live in an area with poor solar gain, but the climate is temperate, so cooling needs are less drastic. I am needing to build a walk in cooler for my farm. I need the ability to store and cool dairy products safely and adequately. I also need locker cooling for aging meat carcasses, and also short term vegetable storage. Much of the year the demands on the system would be rather low. I live in the Pacific Northwest of the USA. Keep the ideas coming! George George Page www.seabreezefarm.net Vashon Island, WA USA This is what I would say is the best solar cooling / ice maker, I have seen in the longest time ( and I have seen allot of them ), in fact the copy I have, is the same one, and down in Texas, I think it would be the best bet. Add some thermal mass to keep it cool even when the clouds are heavy, and you would have your self a prime solar cooler.I have been thinking of modifying it for house AC ( but local code prohibits the use of anything with ammonia without it being installed by a licensed professional ) ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Creating a cool room storage in a hot climate - solar.
Hi Kim and Garth and All ;; They had to store food here before electricity, all I need to find out is how. I think there were many ways of storing food before electricity, but only one involved the cold temperatures that you indicated : Ice storage. In other words, make lots of ice when the weather permitted, and store it under sawdust for when it is needed. As you know, other ways of storing food without refrigeration are drying, canning, salting, smoking, fermenting, etc. The fermented fish they eat over here stays (festers?) for months without refrigeration (but I won't go near it!). if possible I would like to build a natural system that does not require energy. Your idea is a good one. If I may recommend, please see a fascinating web site for a solar ice machine which uses not electricity at all : http://www.energy-concepts.com/isaac.html This one uses water/ammonia system, and needs a heat sink (they call it a thermosyphon) for correct operation. A heat sink is a body of water or a large radiator that can dissipate large amount of heat. The write up doesn't make a big thing about it, but it is necessary for correct operation. Check out the rest of the site for good info about absorbtion. It has been in use for about 100 years. Before that there was only one way to get cold temperatures : ice storage. About 5kg ice per m2 of collector area. 11 m2 system about $7,000. That's pretty good. For another clever system which doesn't need a heat sink, download the pdf file at : www.homepower.com/files/solarice.pdf Also, please search for ammonia ice solar. There is enough info to build your own system. Concentrated ammonia is highly toxic but biodegradable. With proper precautions, operator training, and correct maintenance, the system would be safe. Another interesting possibility is if you have a generator running already for electricity, then the heat of the exahaust gasses (which is waste heat right now) could be utilized to drive the absorbtion process per these links (or free ice!). The exhaut gasses are at least 250 degrees F. In that case no solar collectors would be needed. Hope this helps. Best Regards, Peter G. Thailand ___ Do you Yahoo!? Shop for Back-to-School deals on Yahoo! Shopping. http://shopping.yahoo.com/backtoschool ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
