AC water heater?

[RandyG]

I recently saw a home improvement show in which they hooked up the house AC unit up to a pool heater to use the wasted heat from the AC. I did some research and found it is done on large scales, homes, supermarkets ect. Has anyone done this with a window unit? Is it as easy as running coils through a water tank? I don't have the AC knowledge.

[Shadow Catcher]

An AC is a heat pump, and yes no reason you can not do it, except as the water warms up you lose coolth. Therefore if you are marginal in your AC BTU you may end up a bit warm.

[Socal Tom]

This makes sense for heating a pool, the desired temperature for the pool is 80 to 85F, so that's still relatively cool compared to summer air temps. For heating water for washing, the desired water temp is over 110F, so this will be really hard on the AC to try and cool the interior space, because its pretty warm compared to summer air temps.

IMO It would make more sense to develop a small solar water heater setup.
Tom

[RandyG]

What I have found on the subject says the AC would run more efficient... How would you build it Shadow? I'm not set on the idea yet but looking into it.

[Socal Tom]

What I have found on the subject says the AC would run more efficient... How would you build it Shadow? I'm not set on the idea yet but looking into it.

Just remember to pay attention to the temperature of the water you are heating. At 80F, it would probably be very effecient, but as said before as the temp heats up, the efficiency would drop.
Tom

[eamarquardt]

It would be as simple as running coils through the water of the pool or water heater. If you followed up with a conventional air cooled condenser coil it wouldn't be any worse than just having the air cooled condenser worst case and if you bypassed the air condenser when the air temp is high you could do pretty good. Just doing some numbers in my head each day running an air conditioner unit would raise the temperature of a typical swimming pool about a couple of degrees F. How much of that heat would be lost each night via radiation and evaporation is beyond me but if you did so day in and day out the pool might get too warm to be refreshing.

A friend sprayed water on his ac condenser coils and reduced the current, as I remember to about a third of what it was with just air. I'm not sure how good the water is for coils that aren't designed for working in a water mist.

The whole point of water cooling towers for getting rid of heat by vaporizing water.

See: http://wcec.ucdavis.edu/sandbox/search/ ... tSinks.pdf

If it is as cost effective as the article suggests I'm surprised that it doesn't appear that any one is making such units.

Cheers,

Gus

[Socal Tom]

A friend sprayed water on his ac condenser coils and reduced the current, as I remember to about a third of what it was with just air. I'm not sure how good the water is for coils that aren't designed for working in a water mist.


Cheers,

Gus

Most window units are designed to collect some of the condensation and splash it back up on the coils to help with the efficiency of the units.
Tom

[RandyG]

Wish I could find a cheap used unit to test with, I can't see myself buying a new one and tearing it into pieces and some how hide it so my wife didn't see it... some projects she just doesn't agree with, usually the ones that involve me and money.