Using swimming pool as water source for heat pump AC?

[treepog]

Ok so this may be a VERY silly question but I do not know the answer so please bare with me.

I had a conversation the other day with a friend. He said it was possible to use the water in an in-ground swimming pool as a water source for a heat pump air conditioner? is this in fact possible?

I am sorry if this is a off the wall question but I'd really like to know.

Thanks in advance for any replies

[beenthere]

Moved to geo forum

[treepog]

Sorry about that, I realized I posted it in the wrong section after I had posted. Thanks

Moved to geo forum

[bwalley]

Ok so this may be a VERY silly question but I do not know the answer so please bare with me.

I had a conversation the other day with a friend. He said it was possible to use the water in an in-ground swimming pool as a water source for a heat pump air conditioner? is this in fact possible?

I am sorry if this is a off the wall question but I'd really like to know.

Thanks in advance for any replies

The pool will not have enough capacity, you will overheat the pool, by law a spa or pool can only be 104 degree's F max.

[Vinpadalino]

Try a septic tank lol.

[fxb80]

Went to a house once where the owner had avoided the considerable trouble and expense of drilling a well (couldn't do a ground loop) for his water source heat pump by using the swimming pool. . It was during the winter and the heat pump wasn't heating well. The swimming pool was a sheet of ice. After my "Here's your problem!" he insisted that it couldn't be the problem because there was still water in the pool. Out of curiosity I chipped through a couple inches of ice, found water, and of course it measured 32F. I suggested he contact the manufacturer and ask them how much heat the unit would produce using 32F water as a heat source. He got the expected response from them and ended up paying us to install 20KW of electric backup heat. He later paid us to install an air-to-air heat pump, after a winter of high electric bills.

[teeball57]

They use an aerator to "cool the pool".

[bwalley]

They use an aerator to "cool the pool".

How much heat can you dump aerating a pool?

This as well as the increased heat will cause water loss and increased chemical cost, not to mention making the pool too hot to use.

[Heatranger]

Went to a house once where the owner had avoided the considerable trouble and expense of drilling a well (couldn't do a ground loop) for his water source heat pump by using the swimming pool. . It was during the winter and the heat pump wasn't heating well. The swimming pool was a sheet of ice. After my "Here's your problem!" he insisted that it couldn't be the problem because there was still water in the pool. Out of curiosity I chipped through a couple inches of ice, found water, and of course it measured 32F. I suggested he contact the manufacturer and ask them how much heat the unit would produce using 32F water as a heat source. He got the expected response from them and ended up paying us to install 20KW of electric backup heat. He later paid us to install an air-to-air heat pump, after a winter of high electric bills.

I don't know where this pool was located but I would guess a solar cover coupled with a low watt pump/heat exchanger would have made a big difference in that water. And some of the heated air generated in the bubble thru the day could have been pumped to his air/air heat pump.

[drsmith012]

Try a septic tank lol.

Been done


Being done

[larobj63]

To the OP:

It is entirely possible to reject heat from a living space into a pool. I would strongly advise using a heat exchanger - do not run pool water through teh source side of a heat pump directly.

If you didn't use the space that often, you would likely be fine with the pool as a heat sink, capacity wise. That being said, the cost of the system would be quite a bit more (3x ?) than a traditional split DX system, that would only cost marginally more to operate. In other words - no payback here...

[tedkidd]

Been done


Being done

COOL!

WRT pools. Wouldn't a lot depend on climate and ground temp?

WRT Payback. What solution for $3000 pool heating bill? I'm thinking this would probably be a separate part tied to dx or geo via plate xchng.

[GoofBall]

I want to do this. As someone else pointed out above, it is slightly ridiculous to have a 3 ton heat pump roaring away, 2 feet from an also-roaring 100,000BTU natural-gas-fired pool heater.

The benefits would be:
- The condensor fan could be turned off - would save about 1HP of electricity, which is not insignificant $$$;
- No burning of natural gas at all. Also $$$$
- alot quieter (the only thing making noise would be the pool's waterpump, and the refrigerant pump, wherever that is).


My plan is to splice in a heat exchanger just before the heatpump's condensor coils.

I have a liquid-liquid copper heat exchanger good for 300psi. R410 (or whatever) passes through one side of the exchanger, and poolwater through the other. There is obviously no mixing of the two fluids.

I want to leave the existing condensor coils intact, in case I decide to turn off the pool pump. This just means the R410 travels though an extra couple of feet of pipe before getting to the coils - I can't see this being a problem.


Overheating the pool: We're in a northern climate; I absolutely cannot see this happening, especially if the pool cover is left off overnight. In fact, I'll probably leave the gas-fired plumbed in, just in case.

Can anyone else see any other potential problems?
Any good hints on how to splice in the heat exchanger? I think this would involve recovering/draining all the refrigerant, soldering in the exchanger, and refilling.