Heat Pump Types
Overview of different types of heat pumps.
Heat pumps water heaters (HPWHs) come in two main varieties:
The main distinction between the types is whether the condenser is attached directly to the tank, or not:
- Integral HPs have a wrap-around condenser (either copper coil or aluminium microchannels) where the hot refrigerant gas directly transfers heat to the tank as it condenses.
- Separate HPs use an external heat exchanger to transfer heat from hot refrigerant gas to a circulating water loop. This requires a pump to circulate water from the cold bottom of the tank to the HX inside the HP unit, and send hot water back to the tank in the top or middle.
Many different names are used to describe heat pumps:
- All-in-one or Monobloc: describes a HP where all components are housed in one combined unit. This can either be ‘integral’ or ‘separate’ type, since sometimes the pump and water circulation loop is housed inside a shell casing.
- Split: when the tank and HP unit are separate units. The HP unit can transfer heat by either a refrigerant circulation loop or water circulation loop. The outdoor HP unit can be installed some distance away from the water tank.
- Refrigerant cycling vs water cycling: describes whether the loop between the HP unit and tank is refrigerant or water circulation.