This isn’t a letter from a syndicated advice column. It’s from a forum on “Water-to-Water Heat Pump Operating Problems,” held at the 2002 Annual Meeting of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) in Honolulu, HI.
One of the problems with water-to-water heat pumps, it was acknowledged, is that they need a volume of water flowing at all times. Their biggest advantage is that the heat pump never “sees” the building’s load; it sees the water loop. The water loop is what sees the building. Therefore, water-to-water heat pumps “can work on a retrofit and you don’t care how people use the building,” commented an engineer.