solar powered air conditioning

[cakabo28]

hı everybody,
do you know anything about solar powered air-conditioning or have any sources to get information?
you know we have to run towards alternative energy sources.

[paul_h]

It's not feasible to run a compressor motor with solar power, so forget DX systems.
Look up absorption systems. They were popular 20-30 years ago running off wasted heat or boilers.
I think solar energy may be up to the point to power to run a small absoption plant these days.
http://en.wikipedia.org/wiki/Absorption_refrigerator

[eggs]

Sanyo are marketing one now http://www.sanyoaircon.com/products/solar-powered/
have a look

eggs

[cakabo28]

thanks friends but these applications are too expensive,ıt must be both cheap and efficient.
For example;
for a 24.000 btu/H AC,you have to pay 13.500 $ for solar panels in turkey.It must be another way

[paul_h]

No it's not cheap to get electrical power from solar panels, that's why it's not already common to have solar powered DX air conditioners.
That's why I suggested absorption, as you only need heat, not electrical power, so it's as easy as a solar hot water system.
But I don't know of anyone making small absorption plants.

[Tesla]

I saw a documentry on tv last year - in the usa there are supermarkets leasing solar systems for their roofs over a ten year period. this is only ecconomical by reducing the Peak load, which coincidentally occurs around the same time. adsorption systems are used for generally very big or very small firdges. It would be logical to use solar PV cells for cooling when the payback period is cost effective - which should be soon.

[vasile.casian]

in France is develpoing the the small absotion plants for domestic air conditioning. I'll try to remember the suppliers name.
vasile

[cakabo28]

http://www.solcool.net/

I have found a manufacturer dealing with this project,They have made a package system and have applied to domestic AC.But I couldn't understand exactly how it works together AC and whether it is cheap or not...

[LeighC]

Hello, I have a motorhome with 780 watts of solar modules charging a 450 amp/hour 12volt battery bank & running a 1500watt 12 volt DC to 240 volt AC inverter. This system will run the domestic Fujitsu 12,000 Btu split inverter type AC for a couple of hours before the batteries discharge. It is very hard on the batteries 170 amps when heat loads are high, not to bad if vehicle is precooled off the grid or genset. Also solar only works while the sun is shining so no incoming power to supplement the batteries when trying to sleep at night. Very expensive system for so little ( solar panels $6,000AUD) Genset would be much better & cheaper.
Hope this helps - Leigh

[jong0726]

solar powered air conditioning is really cool

[Tesla]

Hi cakabo
Passed through Turkey a few weeks ago and noticed noticed millions of solar hot water heaters on roofs. They must be cheep!. What about using one of these (or several) as the heatsource for an absorbtion system?

[superswill]

try this link

http://www.daikinaltherma.com:8080/i...ng=en&site=250

http://builditsolar.com/Projects/Wat...ing.htm#Basics

[gramcor]

Hi ,
Maibe is useful this link:
http://www.greenbuilder.com/sourcebook/HeatCool.html
Best regards
gramcor

[icecube51]

hi , i am new,and sorry for mi bad englis.
but why not go back to NH³ ???
its common nowledge that NH³ gets cooler by warming it up...

cya,ICE

[Cold Down Under]

Desiccant cooling may be an alternative - the unit is probably 3 - 4 times the price of an equivalent convential commercial size aircon.

I know Munters make solid desiccant systems but are expensive as their rotors are the most expensive part on top of the other things that you need to march around the psychrometric chart.

Essentially the system operate in generally the same way - you need both heat and water to make it work, and ideall an exhaust air stream from the building. The fresh air stream is dehumified by a desiccant rotor - reducing the absolute humidity of the air at the same time heating the air (the energy source for reactivating - or drying out - the wheel is from any high temperature heat source 80C is the lower limit). The dried air is passed through a energy recovery wheel cooling the dry air - shifting the wet bulb lower (cooling of the wheel is provided by recovery of the exhaust air from the building). The slightly cooler drier air (now with a low wet bulb temperature) is passed finally through an evaporative cooling pad to further cool the air. Air practical limit of 12 - 15C S/A temps is achieveable. This system works well in moderate climates.

[jelecto]

hi , every one, (sorry for my english)
my company just got one minisplit unit witch use a little solar panel to safe 40% in energy. i told my boss that this it is imposible and the trading people said that it work, so far, i no agree with this. i would like your opinion about this.
they conect a solar exchange panel in the suction line

[jelecto]

do u speak spanish?

[rtamayo]

you can visit :
broad(dot)com
this factory build small absorption chillers, they can use solar heater

[satoof]

i think using liquid desiccant air conditioning is so promising, with low temperatures for desiccant reactivation (solar, or waste heat from co-generation) is more than enough.
i think strongly that using only solar energy will be with some risk (for industrial or comfort applications).
i think desiccant dehumidification ( for the handling of the latent load) and then using traditional cooling to handle the sensible load (i.e hybrid systems) is more efficient.
type solar air conditioning in youtube and you will find some good films
sunny regards
Mustafa

[mkardehi]

Hi all ;
using absorbtion chillers is the best case I think , but it's not economical for manufacturers to make small size absorbtion chillers but they do that and there is no limitation on this case , and in this case no electrical sollar cell needed and we need solar panels which generate hot water directly without making any electricity ...this would be a very good solution with really small amount of runing cost ,but in case of 1st cost ,I mean the system price it is not cheap , because high efficiency sollar panels are really expensive now and they will become cheaper in future

[richardb14]

what about passive cooling through a ground loop or borehole?

seems easy enough, a closed loop circuit and a circulation pump, then through a heat exchanger, dump the heat into the ground. would obviously need a ground temperature below 10 - 12 degrees

[richardb14]

or if you are brave enough a fully open system using convectors and no heat exchanger, just one complete circuit.

like a geothermal system in reverse with no compressor

[ahmed cod]

thanks every one.in my opinion it use absorption cycle

[Gary]

hi , i am new,and sorry for mi bad englis.
but why not go back to NH³ ???
its common nowledge that NH³ gets cooler by warming it up...

cya,ICE

NH3 does not get cooler by warming it up; nothing does. Everything gets warmer when you warm it.

[ice_cool]

solar power ac technology still nees to be improved quite a lot.

[ivank2139]

I would like to combine a residential size chiller absorbtion unit with solar panels supplying hot water to drive the process. I cannot find any units in the 3 to 5 ton range that would be acceptable using input heat from solar panels in the range of 195 to 205 degree F water. Can anyone point me to a good supplier of an ammonia based absorbtion unit in this size range?

[CRISTIANCERNAT]

hello evryone
please have a look at our installation
if intereted let me know and i will try to give you more details
search for voltas technologies on a site called engineering news an article of october 13

regards

[mad fridgie]

You could look at "jet" refrigeration, thermo-compressor, ans small liqud pump.
I will explain!
Use liquid pump to lift pressure.
Boil liquid with solar rays.
High pressure vapor injected in the thermo-compressor (venturi)
Suction is the evap.
Combined outlet stream to condensor.
Liquid is split (one to TEV) (one to pump suction)
Small amount of power electrical for pump and fans.

[desA]

^ What kind of pressure ratio can be achieved using this circuit?

If memory serves, the venturi's are not overly good at achieving high pressure ratios. May be enough though, for a small cooling system.

[mad fridgie]

Venturi (s) can achieve high compression ratios. It is all do do with you motive force (incoming vapour stream)
Of course it a question of picking the right refrigerant for the application.
For AC this should be pretty easy as ratios are small as SST is quite high.
Unfortunatley it is not one of those applications where you can just look in a book, even to the point, if it has been done will solar energy. No doubt some one will tell us!

[desA]

^ What kind of pressure ratios could you envisage here?

The heat collector will also be interesting...

[Bradenton Air C]

Hi! thanks for posting this information. It's really helpful to technicians like me... I have encountered solar driven air conditioning and so far I am not having problems with it. Forums like this are helpful because it gives additional information to us. Nice one!

Bradenton air conditioning

[MilosBog]

Sanyo has absorption chiller and i think that Qatar is building something similar

[MikeHolm]

Lots of people have ab or ad...sorption chillers and there are over 400 installations using solar for cooling now. Check out the IEA task 38 (i think) for all the solar cooling info and for links to the manufacturers. Have a good weekend.

[arne22]

Without being a specialist in this area of heatpump technology at all, I think that there is two interesting prinsiples that is mentioned in the discussion above, that possibly could be brought together.

This is the prinsiple of the absorbtion heat pump, and the prinsiple of using relatively cold ground water.

Acording to the first law of thermodynamics no machine can produce energy by itslelf. The energy has to come from somewhere. I guess that also will yeld even for the absorbtion heat pump.

If you want to pump out a energy stream of for instance 3 KW, the energy needs to come from somwhere. So to pump out 3 KW, there has to be a energy flow, somewhere, that is more than 3 KW, to keep this energy flow running, out of the building.

If you in some way consentrate the sun energy using mirrors, or something like that, this wil give a hot area, where the sun energy is "running in". If you then have a cold area that is cooled by the cold water supply from the ground, then there could be a qute lot of kilowatts unning or flowing from this hot area to the cold area.

In some way it might be possible to convert this energy flow from the hot to the cold area, so it in some way or the other, using a absorbtion heat pump or whatever, in some way ends up as 3 KW of energy flowing out of the building.

I gues that these prinsiples of thermodynamics also wil be appliccable, even for an absorbtion heat pump ?
So an absorbtion heat pump should need one relatively hot area and one relatively cold area to set up the energy flow that makes the absorbtion heat pump working.

If this is right, the consentrated sun beam should give a lot of energy flowing into the system, and the cold ground water should take it away. This should give a flow of energy, that can be used for something, for instance to rum a aircondition system, the one way or the other.

I wonder if this is correct, as observed from a "philosophical helicopterview of termodynamics".

Could the absorbtion heat pump benefit or work bether, if combined with cooling water from the ground ?

I don't know, but I think the idea is quite "fun" and interesting. (And I hope the idea is not to stupid, as I really dont know exactely how an absorbtion heat pump works.)

[arne22]

After making a little research on this idea ..

It looks like that the idea of usig a "solar powered hot spot" and a ground water "cold spot" as the power source for a absobtion heat pump has a more direct possible inplementation, that expected.

Look at this figre: Link

Area 7 in this heat pump contains "the hot spot". Area 4 contains "the cold spot".

It should absolutely be possible to "powering the hot spot" using "condensed" sun energy using a parabola or mirrors of kind, ang the effectively transport the heat away, using relatively cold ground water.

Here is a link to a Wikipedia general explantion of the absorbtion heat pump. Link.

Does anyone of you have a "deeper" or more detailed description of the absorbtion heat pump ?

[arne22]

Someting more on applying these prisipples here.