Pool for geothermal

[ArthurHagar]

Caught some ladies talking during lunch the other day and when I heard HVAC mentioned I kind of started easedropping, and what I gathered I couldn't make much sense of so I figured I'd come to here and see if it was something logical or they were just getting smoke blown up their backside.
Their builder told them he would be able to use their pool in the winter as part of their geothermal heat pump to help cut way down on their energy bills. Now I don't know if he meant he would use the pool water as the source for the geothermal loop, or maybe send it through a boiler, or just use the tax credit to help offset the cost of building the pool. I don't know I'm at a lost but am intrigued. So I guess what I am asking is there any way to tie a pool into a geothermal system and make it practical?

[Push It]

I would think it would be more trouble than it is worth. I would not run pool water through my HP with all the chlorine and chemical in the water. I would think you would want a plate heat exchanger in there. Now I do not design, install or have worked on a geothermal system yet but I would belive that the pool simply does not have enough water to support the energy needed for this. You would need another loop I would think.I mean what happens when the pool freezes. Your screwed.


Now maybe it would make some sense in the summer to heat the pool. But I would still think you need a traditional loop.

[waterpirate]

This has been discussed add nauseam and it boils down to " a given volume of water, at a given temprature, with no means of reverseing or adjusting the temp, only has a given number of btu's to give. It takes alot more gallons than people think to pull this off. Not to mention the diminishing return on time and materials to only get a minute benefit.
Eric

[ArthurHagar]

Could you have it on a valve between your pool and a ground supply to switch back and forth between when your pool reaches maximum heat capacity? I know it's a little far out there but maybe a cheaper way to have a heated pool all winter?

[Push It]

Could you have it on a valve between your pool and a ground supply to switch back and forth between when your pool reaches maximum heat capacity? I know it's a little far out there but maybe a cheaper way to have a heated pool all winter?

You cant have a heated pool in the winter. Your heat pumps will be extracting heat from the pool water to heat the house. You will turn it into a skating rink.

[ArthurHagar]

Yea guess that makes more sense.

On a side note though I was talking with the Bard rep at the Expo yesterday and he was telling me how they pump water from a different source around the compressers in the air handler to cool them and improve their efficiency, and then dump that water into a water heater. Thought that was pretty fancy. Seems like someone could come up with something along those lines for a traditional heat pump?

[barbar]

I have undertaken a number of these types of jobs, firstly you must undertake an energy mass balance (will there be enough energy in your pool to meet the heating requirement).
Generally these are suited to temperate climates, where heat load is not massive, and that the pool still can absorb energy from the sun and the ambient. (over time) They come into their own, if you want to heat the pool in summer, and cool you home.
As far as heat exchangers, most now use titanium, so corrosion is not that much of an issue.
Normally as far as I I know most systems are bespoke and are designed and manufactured to meet the application (but i could be wrong on this account)

[Push It]

I have undertaken a number of these types of jobs,

Just curious. Do they pipe it so you can valve off the heat exchanger and flush it to clean it? Does algae grow in the heat exchanger? Have you ever had this problem?

[barbar]

Just curious. Do they pipe it so you can valve off the heat exchanger and flush it to clean it? Does algae grow in the heat exchanger? Have you ever had this problem?

Not had any issues, but as with any pool, keeping the water quality would be important.
The water that goes through the heat exchanger is after you pool cleaning system (sand filter, and doser)

[arc8]

Having a pool indoor and extracting its heat and heating the pool (pool boiler) to maintain its temp just to increase its efficiency (Geo unit); is it cost effective?

Anyone!!

[Oldsolarguy]

It would seem to me the efficiency gained by the geo would be lost in the fuel usage by the pool boiler.

[terawatt]

>use their pool in the winter as part of their geothermal heat pump to help cut way down on their energy bills

As others have indicated this will not work because of the limited BTUs available in the pool. But the pool can be used to reduce cooling costs and at the same time provide free pool heating (summer only). Check out this heat recovery pool heater episode at This Old House website.
http://www.thisoldhouse.com/toh/tv/v...652494,00.html