When AC is being used, an indoor compressor is creating about 25% of the heat load and this heat is adding to the load.  Wouldn't it be better to put the GSHP unit in an insulated room and vent it to the outside?  Might was well put the water heater in there too (since it also radiates heat).

Hi Jon,
Much of the heat added to the load by the AC is internal to the process, not radiated to the building envelope as you are thinking.
But you are correct in that we do generally try to isolate the equipment to keep impact modest. In modern construction, we have basements available around here for the equipment. If folks finish the basement invariably the mechanicals will be seperated from new living space.
If you are shopping for a heat pump, you'll notice when folks do a man j calc that there is also appliance load listed for the other appliances.
Joe

Ditto what Joe said. Certainly the power used by the compressor is ultimately all converted to heat, but most of that heat is added to the compressed refrigerant gas in the form of additional superheat (useful for DSH-heated domestic hot water). Therefore the heat is dissipated along with the heat extracted from the home into the geo water.

Both the compressors and their enclosures are typically insulated for both acoustic and thermal reasons. As a result I would be surprised if more than 5% of the compressor heat makes it into the surroundings via the cabinet.

An issue many don't consider is blower power. Unlike the compressor power nearly ALL blower power winds up in the conditioned air. This is a reason to favor modern efficient ECM motors over the older PSC units.

Makes sense. To get a separation of the heat load of compressor and fan motors from the conditioned air or fluid, I guess they would have to go to a longer drive shaft. And use an external drive motor (with seals) or a carefully designed hermetic enclosure (one that would conduct heat very well from the motor to the outside, but not very well to the working fluid).

Or maybe just run copper cooling lines (plumbed to the GSHP loop)  around the motor and compressor to remove the heat before it adds to the fluid temp.

You first :) Don't want to be on the warranty hook for that one.
j