Technical information

1.10.2 YLHA models: heat pump
Cooling cycle
1 The 4-way valve is activated.
2 Heat exchange takes place between the heat transfer liquid (water or glycol water) and the refrigerant
in the plate heat exchanger. Water is cooled, and refrigerant is evaporated and reheated.
3 Then the Scroll-type compressor condenses the refrigerant (gas) until the condensing pressure is
reached, and the refrigerant goes to the air cooled condensing unit.
4 In the air cooled condensing unit, heat is exchanged between the air and the refrigerant. The air is
heated and evacuated from the chiller (heat rejection).
5 The refrigerant is condensed and sub-cooled.
6 Then the refrigerant (liquid) goes on to the expansion element where it is expanded until the evapo‐
rating pressure is reached, at which time it goes to the plate heat exchanger to start a new cooling
cycle.
Heating cycle
The cycle is reversed to heating mode. The 4-way valve is not activated. The condensing unit becomes
the evaporating unit and the evaporating unit becomes the condensing unit. The water in the plate heat
exchanger is heated.
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Technical Information
1.10 Cooling operation and hydraulic diagrams
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