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Absorbtion chiller A/C

Absorbtion chiller A/C

Absorbtion chiller A/C

(OP)
Hi.
I am building a completely off grid house in Aus, and in summer it can get really hot. I dont wanna have to relly on the batteries and solar for air conditioning in summer. So i am looking into solar absorbtion chillers to cool water for an ac. However I am only really able to find experiments and prototypes and things for the future for domestic use apart from the big ones that cost upwards of 90k to buy. My question is. If i were to adapt a few absortion fridges from lpg gas to solar, could I run pipes into the freezers to cool the water enough to cool the house, obviously the house wouldnt need to cool near 0 but would a few fridges/freezers hooked up like that work at all? Or would it be worth attemping a large icyball(not me attempting l, I'd probs pay someone to build it)?

RE: Absorbtion chiller A/C

Do you also have a lot of land ???

MJCronin
Sr. Process Engineer

RE: Absorbtion chiller A/C

I suggest you do some rough numbers to realise how much energy you need to cool a house. It's a lot lot more than what's need to cool a small insulated fridge.

There a reason why cooling isn't done off grid. Power.

If it's relatively low humidity you're probably better off trying evaporative coolers. Or have a lot of solar panels. Like 50+.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Absorbtion chiller A/C

A recent posting may be of interest - this Organic Rankine Cycle powered - AC runs on R134a as working fluid.

https://www.eng-tips.com/viewthread.cfm?qid=448688

In your case, the electrical heater which vaporises R134a on the ORC side would be replaced with another working fluid that captures solar heat.

RE: Absorbtion chiller A/C

Forget the whole idea. If you have a good supply of cool water, a heat pump would be preferable.

RE: Absorbtion chiller A/C

If you consider that an average single room air conditioner has an average mechanical power of 2-3kW, and your average camping absorption fridge has a mechanical power of 0.15kW, you can start to get an idea of just how many fridges you'd need to adapt to match an air conditioner.
If you then assume that your heat source isn't going to be anywhere near as good as gas, then overall output in terms of heat shifted will be even lower, and you'll need even more fridges.

The above is a long winded way of saying what LittleInch said.

RE: Absorbtion chiller A/C

(OP)
The house would quite large. 300sq f. There is 5 acres of land and the sun is basically always shining. It does sound like it may not be worth it... what about the specifically built water chillers thay are used in large comercial applications? Although the cost of those can be quite alot.

Thanks for all the replies 😊

RE: Absorbtion chiller A/C

How about taking a cue from the folks in Coober Pedy - build a home underground where it is a lot cooler.

RE: Absorbtion chiller A/C

300sf? That's a tiny house!

You have lots of solar, lots of land..

Hands down the least expensive, most versatile, most flexible, most effective, most off-the-shelf, method would be solar power running regular high efficiency mechanical refrigeration.

That would be with the exception of; if your location gets down right chilly at night. Then the most efficient would be to chill water with solar thermal panels at night, storing it in a large highly insulated tank for use in the house during the following day.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Absorbtion chiller A/C

Anecdotal supporting evidence - when I was young, I knew a guy who'd built his house around this principle. The walls, interior and exterior, were built from roughly 6 inch chunks of local coffee rock, cemented with concrete, and had space inside of about a foot. This was then sealed and kept full of water. He used the system as a storage tank to feed the house. I can't remember if the tops of the walls were kept sealed or left open, though I do remember he laid fibreglass insulation batts on top of the ceiling.
End result was small rooms in a big house - but it was always cool inside!
I imagine the same effect could be achieved a lot more effectively using better materials - this guy wasn't well-off and just used what he had on hand.

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