Prototype solar powered air conditioner system achieves 3.5 COP

[brainstorm]

Their claim: 165W for ~2x better power efficiency compared with regular AC systems. All calculations and details on this video:



No compressors (silent), dissecant-based system which, they claim, does not require dissecant re-filling, only water.

Thoughts?

[NiHaoMike]

I wonder if the efficiency could be improved by using fans optimized more for airflow rather than static pressure.

[awallin]

what is the German company making these desiccant ACs, and are they selling any?

[BradC]

Their claim: 165W for ~2x better power efficiency compared with regular AC systems. All calculations and details on this video:

Not quite sure which video you watched as the sum up at the end was "not as good as the prototype would have led me to believe" and generally comparative to a conventional window a/c with a cop around 3.5.

Neat idea, but not even close to a modern high efficiency split (some with a cop ~6).

The reference to the German company was using dessicant in conjunction with a conventional refrigeration cycle to pre-dry the air being cooled and use the waste heat to drive the dessicant regeneration. Again, neat idea.

[Marco]

This kind of stuff is only interesting if you have a source of low grade heat ... and a solar collector doesn't count, because PV is more cost effective.

[dmills]

Absorption chillers have been a thing for the best part of a century at this point, using the sun to provide the hot side is a fairly obvious approach.

[nctnico]

A Dutch company went another route using solar (or waste heat) for cooling. It seems they use a resonating pressure wave (*) to create cold and hot zones in a system. Pretty nifty:
https://newatlas.com/soundenergy-thermoacoustic-cooling/58169/

* Journalists have dumbed it down to sound waves but I think this isn't an accurate description.

[NiHaoMike]

This kind of stuff is only interesting if you have a source of low grade heat ... and a solar collector doesn't count, because PV is more cost effective.

I'm interested to know the total system cost compared to a compressor A/C running from PV via a VFD. Main problem I see is that most off the shelf compressors have a limited dynamic range, making it more complex to effectively use PV without additional energy storage. Once I get around to building such a device, I'll probably add batteries and/or multiple compressors of different sizes to allow operation over a wider range. The main energy storage mechanism would be making ice in large tanks.

[Simon]

Tech ingredients make some interesting stuff but sometimes I wonder if he is just trying to look clever as either the detail is so diluted i get bored or they just skip stuff entirely. Did a couple of videos on making a lovely looking boat and we never even got to see the damn thing float!