DC airconditioners: latest efficient models from Fujitsu

[russ]

Adding water into the back end of a conventional aircon is doable, using a mister, or just a drip, to make sure the hot condenser is well-supplied with coolant. However, it can result in corrosion of the copper-aluminium junctions. This is done and in a hot dry climate seems to work. You need very clean water.

The conventional aircon, with no mister, or any solar turbo, is the most general el-cheapo case, so is the most commonly designed, and the cheapest. There are cases where "Solar" Air Conditioners have added heat from a panel, for magic effect, but even if the physics of this makes sense, manufacturers are behind the times, and don't start with an efficient compressor. (The mass-produced Daikin models use a reluctance motor, which can now be driven properly, by little computers. They claim 20% more efficiency, due to high torque, which is highly plausible. Come on - cut the BS - you are talking about a very big and competitive market - you have not discovered some little trick that the big boys have over looked. They spend big money on R&D.


Here's an analysis of using ammonia as a coolant in a standard-concept air conditioner, getting COP up to 6.

http://www.airah.org.au/imis15_prod/Content_Files/Divisionmeetingpresentations/QLD/PPQLD_24-02-2010SJ.pdf

The efficiency of ammonia is attributed to better refrigerant properties, which makes me wonder when there will be a push back to it, despite toxicity problems.
Wonder all you want - ammonia based refrigeration is not uncommon in industry - as you have noted there are safety considerations - you won't be seeing it in common home use.

They are possible, but electrical solar panels are getting cheap. Will PV solar ever get cheap enough to drive AC - doubtful.

Comments in bold in the text.

[astrayan]

Come on - cut the BS - you are talking about a very big and competitive market - you have not discovered some little trick that the big boys have over looked. They spend big money on R&D.

I was referring to the Daikin models, which rank as the top efficiency model, according to the Australian gov test site. Although the EER doesn't really stand out against LG, who is claiming EER 5.4, Daikin is using a reluctance motor, which I think LG and Fujitsu may not. My point was what you pointed out: that even if Koolsola did find a way of solar-boosting an aircon, they start with retarded technology (EER 3.6)

I think solar can drive aircon, but it has to stop when the clouds start, and there is a problem in the afternoon. Also, there has to be some kind of tracking, or excess of panels, because in summer, the sun gets low, and towards the back.

The main trick would be to lower the thermal mass of the room you are trying to cool. Unfortunately, this means that winter becomes a problem. Winter is best done with large front windows, letting the sun onto concrete. I have done this in my house.