Are you considering an air source or ground source heat pump?
I have a NIBE GSHP. The pipe coming into the house from the underground loop passes along the outside of a basement cool room / cold store. Had I thought about it at the time of installation I would have had it run through the cool room. Currently the incoming fluid is around freezing so it would have been a good & cheap way to cool that room and any heat extracted from the room would have offset the heating costs for the rest of the house. I may still try to somehow use that pipe to cool the cool room.
The manual for my heat pump has a section on "free cooling" which I assume could be also used for something similar. It doesn't give details though. All it says is:
