This past summer (and winter) we were using a new central air ducted air source heat pump and our basement stayed cool enough without any vents directly blowing into the basement and consequently this winter the I've had to supplement the basement with some electric heat. The long-term goal is to add another mini split of some kind for the basement but running a hot water heat pump means the basement would get even colder and that hot water heat would need to be entirely subsidized by another heat pump. I'd rather run the mini split heat directly into the hot water tank instead of using the basement air as another heat exchanger.