Solar Powered Air Conditioning Just Makes Sense
by Lloyd Alter, Toronto on 06.15.06
Some concepts just make sense- like when the developer of a solar powered pontoon boat pointed out-"Since most recreational boating is done when the weather is nice, solar power is particularly well adapted to the task." We were thinking that way while looking for a solar powered air conditioner- when do you need it? When it is hot and sunny. We looked at Justin's SolCool but we knew that natural gas fired AC units or propane fridges existed and thought heat is heat- there must be one somewhere, and put google to work. This is the first of a series- the Direct-Fired Absorption system.(DFA)
Gas fired air conditioners work on the absorption principle. "The distinguishing characteristic of absorption cooling equipment is that it produces cooling by using heat energy as an input, rather than by using mechanical energy. For this reason, absorption chillers were once common in facilities that had large boiler plants with excess capacity during the cooling season. Unfortunately, absorption cooling is inefficient, and absorption chillers appeared destined for extinction." ...In large absorption machines, the actual refrigerant is water at very low pressure. An absorber, usually the salt lithium bromide, is used to move water vapor through the system. Crystallization of the salt is a major operating problem that the design of an absorption chiller seeks to avoid."
Direct Absorption (DFA) was developed in Japan in the 60's and now the world's largest maufacturer is Broad Air Conditioning in China. "To power our absorption cycles, BROAD absorption chillers use a wide range of energy sources: oil, gas, as well as solar power, steam, hot water and exhaust. As our chillers do not use electricity as an energy source, they have the potential to dramatically reduce investment in electricity infrastructure in both public and private sectors." They now appear to be extremely efficient and save lots of electricity.
Finally, we find on their site:
"BROAD strives to be like our ancestors that mastered the miracle of fire, like James Watt who harnessed the power of steam, like Thomas Edison with his devotion to testing and retesting. Our goal is to limit the use of fossil fuels and exploit the use of renewable energies such as solar energy to provide cooling and heating needs.
Two years ago, BROAD provided an American customer with our first solar energy powered air conditioning system. This system has performed exceptionally well to date. BROAD's solar energy engineers and salespeople have drafted an ambitious plan to commercialize the solar energy air conditioning system worldwide."
We did not find the home-sized unit we were looking for, but the peak loads in North America are driven by air conditioning in summer- this looks like a good way of taking much of that off the grid. Visit the surprisingly complete and thorough website at ::Broad Air Conditioning and read their ::environmental manifesto here
It says that the chillers can use hot water as an energy source. What if you hooked the chiller up to a solar evacuated tube for heating up the water?
It seems like you could use those tubes that would get water extremely hot on a sunny day to power these chillers.
Ammonia sorption chillers are extremely efficient...and they have no moving parts outside of the air handlers. Ice rinks and large grocery store freezers commonly use them. Brine is used only as the heat transfer fluid from the sorption unit to the air handler/freezer cabinets. Waste heat is quite efficient with these as well and several distributed power domestic fuel cell designs work with them.
Ammonia kills... If you live near a factory or some large scale facility, don't be surprised that it is full of ammonia. If the integrity of the system is compromised then the releasing ammonia cloud can decimate a bordering neighborhood not to mention any workers in the area. It is efficient but it is dangerous.
My old Servel ammonia frig contained a pound of ammonia. We kept it on the screen porch, just to be extra safe about the CO level from the propane it burned. Ammonia is accutely toxic only in very high concentration and there was not enough in the unit to do anyone any real harm, even if it were released all at once (which is almost impossible unless a car crashed into it).
Ammonia also is highly soluble in water and it is easy to design a sorption system with double hermetic enclosures, a dump tank filled with water to catch any vapors emanating from inside the enclosure, and if needed an emergency "knock down" spray system for aerosols if the ammonia heat exchanger volume is very large. The tradeoff is the local toxicity hazard of ammonia versus the global toxicity hazard posed by C02. On balance I opt for the controllable ammonia risk if it results in less C02 emissions.
@JL: Global Toxicity of CO2? Oxygen is more toxic than CO2 - it's why oxidation is such a problem in so many systems. Only mamals make use of Oxygen... every green thing on the planet BREATHs CO2, which is inert. The only way CO2 poses any problem is when you have so much of it in your environment (house, car) that the % O content of the air is too low. We only breathe about (pulls number out of rusty memory) %23 O in a normal atmosphere at sea level. The rest of what you breath is CO2 and Nitrogen (and mehtane if you're a farmer). Making more CO2 just means more happiness for plants the world over. It's not toxic. CO is toxic since it actually can prevent you from absorbing O into your blood stream once you have inhaled it.
OK you got me. CLimate change impact is indirect to the usage of toxicity is improper --- strictly speaking. But my tradeoff analysis still stands.
Actually, I'm pretty sure that birds, reptiles, amphibians, and insects also breathe in oxygen...
plants breathe oxygen as well. it is required for them to make use of the sugars they have accumulated from photosynthesis. They merely have a net output of oxygen resutling from their photosynthetic processes.
if i wanted to hug a tree i'd cut one down and take it home. other than that, anything that can reduce co2 in the atmosphere is good with me. dunno if this idea is but hey, it's worth a shot.
Does anyone have any REAL products that I can go out and buy related to solar power and air conditioning?
See this for a system that was installed in 1979 at the U.S. Army Yuma proving Grounds:
http://solstice.crest.org/renewables/seia_slrthrm/43.html
I am a professional in the grocery business, and I can tell you that my company DOES NOT USE ammonia in refrigeration. Nor does any other grocery company I've known anything about.
Most grocery companies got away from ammonia decades ago because of the inherent dangers.
Our refrigeration techs talk of the bad old days of truly deadly ammonia leaks. Modern multi-compressor rack systems use non-CFC gas refrigerants that, while not human-friendly in large doses, are generally non-lethal.
I'd like to echo opinions from other pros that switching to ammonia and nitrogen gas for residential applications is a bad idea. Residential systems are generally ignored until they go bad, i.e. they are not well-maintained and checked for signs of impending failure, and a failure occuring with a houseful of sleeping people could be catastrophic.
Can I be a pain, and repeat a previous comment....
Can anyone point me at real products, beign sold, for home airconditioning making use of solor power.
Also, any article/book etc explaining more the Direct Absoprtion technique would be appreciated.
Sri Lanka is a tropical country with hot weather almost all year through im very interested in investing on an agency which can suply solar Powered air conditioning for domestic and commercial use i also have other agencies and can match reqired criterias...
Buddhika (Ace spencer (Pvt) Ltd
The trouble is most normal airconditioners use a large ammount of power about 1500 watts and the cheapest solar pannels you can get are about $5 a watt that $7500 and then you need transformers and some electronics say $500 and and air conditioner cost about 1500. All doable but it adds upto about 10k for air conditioning.
can i get the details related to marine solar panel powered airconditioners
i want a project detail about solar acs an wanna know the feasibility of this machine in the international market if you wanna give me the right to sell in the international market i amreally impresed by your project though it was my dream to make it
an alternative to ammonia and lithiumbromide (LiBr)absorption systems are similar systems that work with zeolite, silica gel or calcium cloride (caCl) as absorbers and water as absorbant. I am no technician, but as far as I understand, these aDsorption systems have certain advantages: the active ingredeients are environmentally friendly and not toxic in any way. The systems work under low pressure as opposed to the high pressure systems of ammonia and LiBr based aBsroption systems. the only bavkdrop me be that they are not suitable for icemaking as the minimum temperatures are above freezing point. I am not sure about this though, but if so, who cares. For cooling purposes no ice is required. I am collecting info about these systems as I want to use a solar based adsorption air conditioner foor cooling a greenhouse in a hot and humid tropical country with plenty sunlight evey day. So far I have only found industrial size applications, but if anybody knows about a small scale system, please let me know: cwilfrid@wanadoo.nl
nice post. interesting project. would also be interested in more infos
I'am currently building a ammonia solar powered airconditioner.Should be finished in a month or two . I'am using approx. 14" pipe about 17" tall for the generator and a old aluminuim condenser run to reciever from there it goes to the evaporator which is made out of aluminum.It will be intresting to find out how much cooling it will produce.The pipe will be replaced with a alluminum generator once I determine the size required for a 5 ton capacity unit. The ammonia will not mix with the conditioned air space but with the chilled water produced by the unit.
Regarding non-electric air conditioners,
who, besides BROAD, are the market leaders?
I am interested in learning if real development is underway for a direct absorption air conditioner which uses solar energy in lieu of a gas burner. The unit would route closed-loop fluid through solar panels similar in principle to those used for water heaters. It would not use photo-voltaic panels for this energy source. It would be a peaking unit to parallel with existing compressor-based home air conditioner. especially well-suited to the Palm Springs desert climate. Air conditioning demand has a dramatic daytime peaking phenomena in this very hot, but dry climate. There are large parabolic solar collectors which pinpoint solar energy on a heat exchanger that heats closed-loop fluid which drives a electric generator. Perhaps this approach could be used for providing a "solar gas burner" in the residential size unit I'm envisioning.
How about an RV system? Rather than use solar, it could use all that waste heat being produced by the engine. Seems to me that such a system might work traveling down the hiway at 60 mph. As this is when you are making lots of engine heat and enough airflow to keep the condenser working well.
Granted this system wouldn't work when parked, but, much of the time, there is shore power to plug in the conventional system then.
I wants to buy a Home need small Solar power air conditioner, from where I can buy it, is it available in Sri Lanka or Singapore
Priyantha from Sri Lanka
Looking for information about your A/C systems.
The amount of ammonia used in most residential systems would be lethal, only if you happened to be standing next to the unit, when it released all of the ammonia in one great burst. Freon, however, if burnt becomes a lethal gas similar to that used in World War 1. Breathing this gases cooks the interor of the lungs so that no oxygen can be absorbed into the blood stream. I spent 25 years in the HVAC business and there were several industrial accidents reported about large freon leaks in small spaces that killed. This is due to the displacement of oxygen. That same scenario could be carried out by CO2. CO2, by the way is not inert. It is a conbination of one carbon atom and two oxygen atoms. Plants split this bond to use the carbon and excrete the oxygen. Unfortunately, the animal kingdom does not, generally, possess the ability to split these molecules. Some of you dummies need to read a book or try to remember you high school science classes.
I am looking for information about gas fired air conditioning units. Who are the makers? Are there units for residential uses? What are the main producers in US? in Far East? What are the typical prices for different capacities?
Thanks
Please my name Anas l studing master degree in jordan university im looking now to subject to my thieses i intersting to AC field so i want to choose how to reduce the load of compressor by solar energy so please if there are any paper to help me in this field please send it to my mail
thanks ans best regards
i'd like to buy one too. this can cut down 90% of domestic electricity bills.
Ivan
I'm need more information on your products.
Have viewed the many comments on solar air conditioning, you all are stuck in cooling large rooms, how about small units for the individual, solar powered, refrigeration gloves cooling the hands, neck, feet or arms?? an environmental suit or device to allow us to go into the heat and use the sun to power our unit?? Think out of the box, then out of the box that that one is in and thenout of the box the other two are in.
Refrigerant A/C units are all designed to waste energy and not to economize(wise useage) on energy consumption.
If indeed the earth is warming then these devices will be in demand, must be inexpensive to make in great quantities.
The USA Army and other military global giants, hav been investigating and eveloping such units.
The first one to market with a reliable unit will get richer than billgates. Who wants to be that rich?
I found plans to make ice from the use of the parts from a small refridgerator and a plastic cooler filled with brine. Now if you ran a coil of water/antifreeze through the cooler and then up to an a/c air handler. Than should eliminate the outside unit which uses the most energy in the system. You could use PV cells and an inverter to power the ice maker and maybe even the motor in the air handler.
If you really want to get serious about enviormental
friendly air conditioning and heating, look into direct exchange heat pumps. Their efficiency is greater
than anything else available. The cost of installation
is greater, but the payback is worth the cost. The US is really behind in the development of this, our US economy is fuled by oil companies and too many of us have stock in them. We can all hug trees dig shallow holes in the ground and save our planent.
I have several different ideas for solar use. And if you are interested in hearing about any or all of them to feature in your line of services, please e-mail me back and we can talk. I already have working prototypes if your interested.
Of course the company also sells valve stem caps they claim increases MPG and tire life and improves handling and ride as well as braking. Can you really trust a company who woud market such nonsense?
I want some more information on solar powered acs. I want to do business in india. So please give me the stockist and manufacuteres list. thanks.
Hi there guys!
There are already commercial products available. I've found this one, but there are probably more around:
http://www.coolmax.com.au/coolmax/solar-brochure.htm
The prices are in Australian Dollars.
Good luck in import and sales - solar powered air conditioning is definitively the future!
Remember that the world uses much more energy for cooling than for heating, so now it is time to take advatage of the global warming and convert it to cooling of our houses!
Using solar energy for air cooling is a winner every time.
My friend Lui has purchased one of the smaller BROAD ( http://broad.com ) gas fired units and is using it to cool his office in New York City.
Because he is surrounded by taller buildings, he gets sunlight only for a small part of the day, but the gas-fired unit is working well. It's a Lithium Bromide unit, he is going to buy a ROBUR ( http://www.robur.com/home_eng.jsp ) unit, which is ammonia based, for comparison.
My offices are in Las Vegas, Nevada, and i am working on a cheap solar concentrator. The real challenge to using solar energy as input to heat driven coolers is the area of collection required.
A 5 ton air conditioning load requires about 30 square meters of sunlight, based on 1KW/M^2 insolence and 5.8 KW per ton.
The 1KW number is very conservative for Southwest USA, the "official" peak insolence is 7KW/M^2 !
So, although heat operated chillers are available, the ability to economically collect solar energy lags behind. I hope my work in this area will result in a low cost concentrator.
I've recently been researching solar-powered absorption cooling and other technologies. At this point, the jury is still out for me on which type of refrigeration technology is best matched to solar.
I found this company from Germany that has an interesting dessicant-based unit:
www.sortech.de/
Lots of sources for high-efficiency vacuum tube solar collectors: www.apricus.com
some even from China:
www.sundasolar.com/
good luck,
Kevin
Thanks for very interesting article. btw. I really enjoyed reading all of your posts. It’s interesting to read ideas, and observations from someone else’s point of view… makes you think more. It’s really good written and I fully agree with You on main issue, btw. I must say that I really enjoyed reading all of Your posts. It’s interesting to read ideas, and observations from someone else’s point of view…
Hi,
I saw that Broad (thanks to Dagfinn) sell a gas powered A/C unit. Has anyone actually tried this? I mean does it act like any other A/C at the end of the day? I.E does it cool a room down and get rid of high humidity?
I would love to use a gas powered A/C for a condo project, but I am worried that the the Gas units will not rid the air of high humidity like the sadly lacking swamp cooler, which is useless in the tropics.
I really want to keep to Solar and LPG if I can.
Anyone got any reviews or any help?
Hi,
I saw that Broad (thanks to Dagfinn) sell a gas powered A/C unit. Has anyone actually tried this? I mean does it act like any other A/C at the end of the day? I.E does it cool a room down and get rid of high humidity?
I would love to use a gas powered A/C for a condo project, but I am worried that the the Gas units will not rid the air of high humidity like the sadly lacking swamp cooler, which is useless in the tropics.
I really want to keep to Solar and LPG if I can.
Anyone got any reviews or any help?
the Solar Air conditioners will be available in Australia in a few months. Andrews Solar are manufacturing them in Sydney, and are taking orders. They can be emailed at video33@msn.com
solar powered air conditioning is on the rise. i have personal experience with one of two solar hot water powered, LiBr/H20 refrigerant systems in the United States scaled for residential use, nominal 4.5kW (or about 1.28 tons). these units are still very expensive but the Spanish company who makes them, Rotartica, is embarking on emblematic projects that will promote and display the unit/technology. these efforts will help educate the consumer as well as bring down the cost through increased market demand. the company for which I am associated Schroder Zimmerly (http://SchroderZimmerly.com) is promoting this product in the United States and can provide resources for making residential solar powered air conditioning a reality.
Dear Alll,
Please help me..
I am looking for Ammonia Absorption Refrigeration (AAR) for use in rural area of tropical country, Indonesia. This unit will be use to generate ice about 2-5 ton/day.
Regards,
Rudy
US is really behind in the development of this, our US economy is fuled by oil companies and too many of us have stock in them....