Code 2.201
Split heat pump system with inertial storage on the return line

The system essentially consists of a closed circuit which includes:

  • Split heat pump
  • Water treatment devices (dirt separator and deaerator) for the protection of generators and, more generally, all system components
  • Diverter valve for priority domestic hot water production
  • Inertial storage to guarantee a minimum volume
  • By-pass valves to guarantee a minimum flow rate
  • System charging unit with pressure reducing valve and backflow preventer
  • Heating and cooling system

The solution is suitable for small systems, where the circulators for the heat pump are capable of directly supplying the heating and cooling system. 

The following operating modes are possible:

  • Priority domestic hot water (DHW) production
  • Heating & cooling and defrost cycle

The by-pass valve guarantees the minimum flow rate required by the heat pump, if the flow rate is reduced due to individual temperature regulation in each room, and allows the heat pump to carry out a defrost cycle even when no request for heating or cooling has been made.

Note: The control, expansion and safety equipment must be sized according to the heating capacity and specific characteristics of the system, in compliance with current legislation. The electrical connections must be assessed in liaison with the relevant organisations to guarantee observance of operational and regulatory requirements. This configuration can also be used in the version with monobloc heat pump, adding antifreeze valves to the external pipe.

Caleffi S.p.a. declines any responsibility arising from improper use of the data contained in this document. The diagrams are not a substitute for HVAC system design.