The system essentially consists of a closed circuit, consisting of the following elements:
· Condensing boiler
· Split heat pump with external unit and internal unit
· Inertial storage
· Diverter valve
· By-pass valve
· Water treatment devices (dirt separators) for protecting generators and the other system components
· System charging unit with pressure reducing valve and backflow preventer
· Heating system
This solution is generally adopted in the following cases:
· Renovation: adding a heat pump to an existing system with wall-mounted boiler
· New systems using non-integrated generators
The layout is optimised for a heating system, allowing:
· Heating using only the heat pump
· Heating using only the boiler
· Heating and defrosting using both generators at once
· Instantaneous domestic hot water production using the boiler
The solution is suitable for small systems, where circulators for each heat source are capable of directly supplying the heating and cooling system. The combination of three-way valves and the inertial separator allows the following operating modes:
· The heat pump supplies the heating and cooling system with the boiler off, or produces domestic hot water (DHW)
· The boiler heats the system with the heat pump off
· The heat pump and boiler work together during the 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
