Using swimming pool as water source for heat pump AC?

[Heatranger]

the reason for the surface area is because the biggest heat loss from a pool is evaporation. I think the pool would have to be covered to hit the 104 myself

Anything will soon reach a point where it can not absorb more than phisically possible. That is why the excess must be dumped.
As for too much heat it is best to let it be absorbed back into the biggest heat sink in the universe. And that would be the UNIVERSE. "Nocturnal Radiation" is a passive method. It let's the black night sky cool the water. As with any heat exchange the more surface area exposed to the night sky the better. Then you add evaporation techniques. Coupled with venturi methods.
Smart building is the first step. Making stupid buildings livable is much more difficult than designing a smart building to begin with!

[Carnak]

1000 btu/lb as it evaporates,pretty hard to top that, 1 btu/lb as it heats up.

Agree on smart building is the first step, except I would call it "not a stupid building"

[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.

[Heatranger]

1000 btu/lb as it evaporates,pretty hard to top that, 1 btu/lb as it heats up.

Agree on smart building is the first step, except I would call it "not a stupid building"

Evaporation is hard to beat. I just think that the less water that has to be replaced the more stable and less maintenance is required.
Here in central NC we have a few real cold and a few real hot days. Therefore we try to focus on the normal "very cool" and "very warm, humid" days.
We flip the swith just like everyone else when it comes to the extremes. But saving energy dollars day in and day out requires a system that only needs to knock off a few degrees one way or the other.
I am working on a project involving an abandoned pool that I want to bury a coil into and top the pool area with a greenhouse/shadehouse.
This will allow me to collect heat in the winter and coolth in the summer.
I will "wrap" a coil beehive around a traditional heat pump and it will work with the tempered air.
What do you think?

[beenthere]

I am working on a project involving an abandoned pool that I want to bury a coil into and top the pool area with a greenhouse/shadehouse.
This will allow me to collect heat in the winter and coolth in the summer.
I will "wrap" a coil beehive around a traditional heat pump and it will work with the tempered air.
What do you think?

Won't get enough heat transfer from the beehive coil.

Probably freeze the water in the beehive coil in winter.

[Heatranger]

It won't have 'water' in it. It will be well protected from freezing by having an additive. This anti-freeze will increase it's ability to absorb heat and resist freezing. Constant circulation will make it act just like atmospheric air. Changing constantly to provide move btu differential.
What do you think?

[beenthere]

Antifreeze generally decreases BTU output.

Condenser coils are finned to get a 15 to 20° delta across them.

Can't see how just a beehive coil of copper that is letting 750 to 1250 CFM(if it doesn't let enough air go through you have no performance increase, and may decrease it) per ton of the heat pump go through it is going to have enough heat transfer ability.

[ACFIXR]

Anything will soon reach a point where it can not absorb more than phisically possible. That is why the excess must be dumped.
As for too much heat it is best to let it be absorbed back into the biggest heat sink in the universe. And that would be the UNIVERSE. "Nocturnal Radiation" is a passive method. It let's the black night sky cool the water. As with any heat exchange the more surface area exposed to the night sky the better. Then you add evaporation techniques. Coupled with venturi methods.
Smart building is the first step. Making stupid buildings livable is much more difficult than designing a smart building to begin with!

What a statement!

[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.

[dbooksta]

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.

Exactly: I'm also in the NE, where we generally have cool nights and no shortage of water, so if the pool ever did get too hot all I'd have to do is turn on an aerator or water feature to increase evaporation and dissipate the excess heat.

(Obviously this is only for spring through autumn use; wouldn't try to run the pool loop in the winter with a frozen pool as heat source.)