Unlike in competing units, there is an outdoor unit containing only an air coil, fan, expansion valve, and outdoor temperature sensor.

All other components, including compressor and electronics, are contained in the indoor unit. This has several advantages in this kind of water heaters: minimal installation and service work outdoors, components are in the conditioned space for longevity, antifreeze is not required in the water loop, no electric compressor heater is required, and directly heating domestic hot water is possible (through a desuperheater circuit) since the potable water lines are indoors and will never freeze.

The heat pumps will be set up to heat or cool water in a buffer tank to a user-selectable setpoint temperature; when a zone thermostat requires heat or cooling, it will receive water flow from that tank by opening a zone valve or starting a zone pump.