I am seeking information regarding heat exchanger medium. I plan to install either an air to water or ground source heat pump of around 12KW in a domestic environment. My main problem is to find out if the heated/cooled water is directly used in the heat exchanger mounted in the roof or do I need to have a refrigerant based condenser/evaporator, and what would be the efficiency of both when compared. our climate ranges from 5c to 45c winter to summer.
Many thanks in anticipation, I'm a new Australian member of your terrific forum.