The system comprises:

• A polyvalent heat pump (marked with the letter P), which is capable of producing hot water and cold water at the same time
• A reversible heat pump (marked with the letter R) which can run to produce hot water or cold water
• A system with 4 pipes, where heating and cooling lines are separate
• Two manifolds to which the machines are connected
• Two hydraulic separators which also function as a buffer tank for storing the energy required for the machines to work properly
• Two storage tanks for domestic hot water production 
• A module with boilers in cascade so that the supplied power can be modulated
• Safety devices specified by INAIL regulations, as the power level is over 35 kW
• A hydraulic separator, after the boiler module, dividing the primary circuit from the secondary circuit
• Two booster circulators; in this configuration the heating function and domestic hot water production can be maintained at the same time for the HPs and for the boiler unit

Hot water production takes place via a circuit fitted with:

• A first storage tank for pre-heating connected to the heat pumps by means of a three-way priority valve 
• A second storage tank inside which is a coil connected to the chill water circuit, with the task of completing the pre-heated domestic water heating phase in the first storage tank

During the heating phase, domestic hot water production takes place both through the polyvalent machine and the boiler: DHW is produced to heat the first cylinder while the boiler heats the second. 

During cooling, the polyvalent machine can produce cold water for cooling at the same time as producing domestic hot water, using the condensing heat generated in the first procedure. The reversible heat pump can be used for chilled water production at the same time as – or as an alternative to – the polyvalent machine. The boilers can produce hot water for heating and cooling at the same time as DHW during winter, or can be used for DHW only in summer.

In fact, the layout allows operation in various configurations:

1. Both the generators are for heating and domestic hot water. The reversible heat pump (R) produces hot water for heating and cooling. The polyvalent HP (P) is dedicated to pre-heating domestic water. The boiler works in integration with both the heating side and the domestic hot water production side.
    
2. Heat pump for cooling and both generators for domestic hot water. The advantage of having a polyvalent heat pump (P) lies in being able to perform cooling while using extracted condensing heat to produce DHW in the pre-heating cylinder. The boiler increases the temperature to higher levels in the second DHW storage tank. The reversible heat pump (R) is dedicated solely to the production of chilled water.