I’m fortunate to be living next door to a very unique hydronic heating/cooling system.
It’s in a new home built by my daughter and son-in-law, and it’s a one-minute walk down the road from where I live. The home has a “wish list” of contemporary energy systems, including well-insulated thermal envelope, passive solar orientation, a 7.8-KW solar PV system, a geothermal water-to-water heat pump and a low-ambient air-to-water heat pump. My daughter would probably tell you there are other nice things about the house, such as kitchen cabinets built by local Amish, and lots of closet space, but for me, the energy systems are the preeminent features.