I have a well that flows at about 2.5 gpm 24/7/365.25 unless I pump water out of it faster than that. When I put the addition on my house I ran pipes with the overflow into my basement to possibly use as a geothermal heat source. I can not for the life of me understand why they don't make mini splits with a modified outdoor unit for the basement that has liquid to liquid heat exchangers rather than the liquid to air heat exchanger with the fan. I would like to get a minisplit and take the outside unit apart and replace the heat exchanger with liquid to liquid heat exchangers. If I used 3, for air conditioning in the summer I could use one to dump the heat into a tank of water the heat before my electric water heater. The next heat exchanger could heat my hot tub. Then the last one could take the remaining heat and dump it in the runoff from the well. I can't understand why I can't just buy such an animal. I know I am not the only person with a flowing well. At least 2 of my neighbors have them as well. If I wanted more flow from my well I could dig it up again and put in some pittless adapters and pump water through at a higher rate from lower in the well. Another solution that would probably be easier would be to simply put heat exchangers in the line going back to the outside unit. That option is fine for AC but it would cause issues with heating. What do you think?

Try google with "water to water heat pump"

Perhaps I am not searching for the correct thing. But the problem I have with water to water heat pumps is that they don't have the air handling units that are part of mini-splits.

A GSHP called a split unit has the compressor and source heat exchanger in a indoor unit. Sends refrigerant to an air handler.

Whether those line sets could be married to a mini-split head instead of an air handler I do not know.

ChrisJ

Mitsubishi, Panasonic, Trane, and maybe some others have commercial water source variable refrigerant flow (VRF) systems that are close to what you are describing I think. These could be applied to a house if one wanted to.
I'm envisioning one or more indoor fan coils, or ducted air handling units with a refrigerant coil (for heating or cooling) connected to an indoor compressor unit that rejects heat or draws heat (in heating mode) from a source of water. This "source" of water could be made closed loop and controlled to elevate the temperature in the summer and with careful piping and control this water/fluid, could be piped into as many heat exchangers as you want, to heat (in the summer) domestic hot water, hot tub, pool, etc. These would be piped to ensure that heat is rejected to the various loads in decreasing order of temperature or hottest loads first, if all heat loads are satisfied, excess heat could be dumped via a final liquid to liquid heat exchanger with well water on the other side. In the winter the entire system could potentially reverse and source water could help keep something cool or cold like a fruit cellar or walk in cooler. However, I've never seen this done before and usually in the winter heating mode all the heat is extracted from a borefiled (closed loop) or well water (open loop).

I think it would be hard to recoup your initial investment for single family homes as you need lots of hours with simultaneous heating and cooling loads, to produce savings to offset the cost of the system including the VRF units, and the water side components (pumps, valves, pipes, and multiple water-to-water heat exchangers). Also, in this style of equipment the smallest unit I am aware of is 6 tons nominal capacity, which is probably a bit over-sized for some(maybe most) houses.

"I think it would be hard to recoup your initial investment for single family homes as you need lots of hours with simultaneous heating and cooling loads, to produce savings to offset the cost of the system including the VRF units, and the water side components (pumps, valves, pipes, and multiple water-to-water heat exchangers). Also, in this style of equipment the smallest unit I am aware of is 6 tons nominal capacity, which is probably a bit over-sized for some(maybe most) houses. "

The initial investment for something like that would be almost impossible to recoup. And 6 tons is more than just a bit over-sized for my home. That is why I think my best approach is to take a mini-split and take the outside unit apart, replace the heat exchanger with liquid to liquid and be done with it. It just amazes me that they don't just make something for this. If nothing else for air conditioning people watering the lawn in the summer could water it with warm water rather than cold to increase the efficiency of the air conditioner. Just as good is a take of water to preheat water going into the water heater.

Posted By btg on 20 Feb 2015 08:32 AM
Perhaps I am not searching for the correct thing. But the problem I have with water to water heat pumps is that they don't have the air handling units that are part of mini-splits.

Sure they do Where have you been looking? Bosch makes W/W units and Hydronic Air Handlers to match.