Energy Matters Forums

[Paul]

Is it feasible to develop solar powered air-conditioning?

[MichaelB]

Hi Paul,

Welcome to the forums - yes, it sure is. There's some products already around or in development:

http://www.energymatters.com.au/index.p ... cle_id=307

http://www.energymatters.com.au/index.p ... cle_id=556

.. and I have a small solar powered air conditioner; well it's powered by a solar panel/battery setup anyway; works very well too - draws less than an amp (10 watts) and under a litre of water an hour:

http://www.swampy.net/wb.html

It won't cool a room, it's just a personal air conditioner, cooling the immediate area you're in - but it does that very well. Tiny, but very powerful.

You can run a larger evaporative air conditioner off a solar rig, but they do tend to be a lot more power (and water) hungry. I think most start at around 150 watts and a few litres of water an hour.

[Paul]

Thanks

[greg c]

Yazaki are the pioneers at this and installed some units in Australia in the '70s.

http://www.solarpanelsplus.com/yazaki-solar-HVAC/

http://www.yazaki-airconditioning.com/e ... story.html

It uses the absorption refrigeration system like you find in gas fridges. Simple

[purplepete]

As well as the aforementioned products & suppliers, a US mob from Colorado with the well-thought out name Coolerado are now apparently supplying into Australia; they're claiming the sort of efficiencies with units already working that Air Change say they will eventually be able to obtain (good news for consumers, not so good news for Air Change & local researchers, although I think the 2 systems may be able to be combined). A Russian immigrant (Dr. Valeriy Maisotsenko) came up with the technology some time ago, and they've apparently been producing units since 2005.

I don't have a unit or know personally anyone with one, however, so I'm just reporting on the figures they give. For more information check out http://www.coolerado.com/ and http://pesn.com/2009/09/03/9501566_Coolerado_super-efficient_air_conditioning/ and http://peswiki.com/index.php/Directory:Maisotsenko_M-Cycle_Coolerado.

The latter link also describes the "Maisotsenko cycle" (i.e. the thermodynamics behind how this system works) and how it could be applied to other technologies (like internal combustion engines).

[jdaley]

You will not need air conditioning if you create cool drafts via a wind tower, that is how they make ice in the middle of the western Sahara.
The trick is simple but complicated in that air is drawn over water and up through a tall twoer you buidl in you home. Research it and you will be fascinated.

[brianbrennan]

dear paul - i am a refrigeration + air conditioning mechanic with 30 years experience, the evaporative systems people suggest at times work by evaporating water, so work well in dry climates and are cooling only-they are nearly useless in humid climates such as darwin sydney etc yes sydney has generally humid summers-
a normal air conditioner or fridge uses a vapour compression system which tranfers heat from inside to outside for cooling or outside to inside for heating in this the air conditioner (a modern one) uses 1 kilowatt of electricity to move up to 3.5 kilowatts of heat.
an absorption system uses a mix of water, amonia and nitrogen, the water and amonia absorb into each other and cool in doing so, but cannot heat ,the water and ammonia is then separated by any form of heat applied to the absorbed amonia and water to separate them ,then they absorb again and cool this process uses 1 kilowatt of heat(produced by any form ie kero/gas/12volt/240volt/solar) to move 1/3 of a kilowatt of heat
most older and modern mass produced homes are absolutley terrible in design for our climate and require heating in winter and cooling in summer.
it is generally best to buy a modern inverter normal air conditioner and install grid connected solar to offset the electricity used it is also highly benficial to design/adapt your house as best you can to minimise the size of air conditioner required.
it is also benificial if you have a two storey home with bedrooms upstairs install a small ducted inverter system 8-10 kw to cool or heat bedrooms for an hour before bed, and a split sytem 6-8 kw if approproiate for the living area for most of the use- will cost about same or less than large ducted system 14-18kw but you will only be running 6-8 kw machine most of the time instead of 14-18kw machine most of the time as well as other benefits - brian

[bpratt]

dear paul - i am a refrigeration + air conditioning mechanic with 30 years experience, the evaporative systems people suggest at times work by evaporating water, so work well in dry climates and are cooling only-they are nearly useless in humid climates such as darwin sydney etc yes sydney has generally humid summers-

Those evaporative systems are what people were using in Brisbane some 25+ years ago, and people were complaining about mould growth in their houses from their a/c systems, and that's why for such a long time homes in SE Qld never had a/c in them.

In the humid climates, adding more moisture in the air only creates more of a mould problem.

But A/C used properly is very much a good thing, particulary as they are the most efficient form of heating during winter.

[jdaley]

the evapourative ones work beautifully in the dry areas, albiet, they do use a fair bit of water but with some lateral thinking that may be solved by distilling grey water in a small solar set up and diverting the condensate [ fresh water ] to the unit. Since it would be needed only on hot days all links in the chain would be working at peak efficiency.

[ulysses2120]

Check out these guys, there is a couple of good demo vids on there website as well.

http://www.coolerado.com/