What does it take to get a water heater air-conditioner and heater mini-split?

I think you may be referring to this article here perhaps about the Edelweiss House where we used an air source heat pump as well as an air to water heat pump water heater?

Increased efficiency with an air source heat pump and heat pump water heater working in tandem

A heat pump water heater will act to cool a house, but unless your home is fairly compact, extremely well-insulated and airtight, it likely wouldn’t cool your home anywhere near enough to be a viable alternative to a mini split heat pump air conditioner.  We used an air source heat pump to feed a heat pump water heater in the Edelweiss LEED Platinum Demo house, and since with was a superior building envelope the water pump did provide a noticeable difference, but that combination won’t always have the same effect. We also did have other cooling strategies, including window shading and a mini-split heat pump.

And an important note about air to water heat pumps – during the winter months it will draw in the air from the home to generate hot water, and eject cool air, but it is only as efficient as your other heat source. Meaning, if your home is heated with heating oil, natural gas, and your water heater uses that heated air, your water is also effectively heated with that same fuel. It’s just a consideration worth remembering, they are a great product but in some cases it isn’t always worth the added investment. If I have misunderstood what you are asking please feel free to write more details.