Learning how to help the passive solar design features keep us warm in Winter is a useful exercise. Sunlight is all we need on clear, cold days. When it's cloudy, we use the heat pump to stop the concrete slab thermal mass cooling too much.
Using heat pump technology for both the reverse cycle air conditioner and the hot water system is an efficient way to meet those needs. Despite the warm weather, the air conditioner is yet to be fully tested as the passive cooling features in the house have kept this heat pump on standby duty.