The closed-loop water source heat pump system is simple by design, yet it is among the most efficient HVAC systems available. These systems take advantage of the heating and cooling requirements of each space in the entire building by recovering otherwise wasted energy in some spaces and better utilizing it elsewhere in the system. 

The system is comprised of highly efficient packaged reverse cycle heat pump units interconnected by way of a water loop. Each unit satisfies the air comfort requirements of the particular zone in which it is installed. In cold weather, the heat pump removes heat from the water loop via the unit's specially designed refrigerant-to-water coaxial heat exchanger and transfers it to the air.

In very cold weather, when more heat is required than is being internally generated in the building, and most units are operating in the heating mode, heat is provided to each individual unit from the water of the loop. If more heat is needed than is naturally in the loop water, an energy efficient fluid heater attached to the loop is required.

In hot weather, when most or all of the Henry Heating & Cooling Comfort System units are operating in the cooling mode, heat is being taken from the zones in the building and rejected into the water loop. If not required somewhere else in the building, the heat is rejected from the building through an external fluid cooler attached to the loop. 

Balanced energy use. However, during certain times of the year, units in different zones may be operating in different modes, heating and cooling different spaces at the same time. When this occurs, heat is moved from one area to another via the water loop. During this time, the loop may not require either heat rejection or supply. This is when the system is most efficient. This is in contrast to fan coil systems which may require both a boiler and chiller to be operating simultaneously (4-pipe) or utilize inefficient electric heat.