Refrigerant Circuit Component Allocation, Influence On High And Low Pressure Sides: Notes

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The condenser, receiver/dryer and the restrictor or expansion valve to separate the high and low pressure liquid ends are located on the high pressure side.

High pressure results from the restrictor or expansion valve forming a constriction and causing the refrigerant to accumulate, thus leading to an increase in pressure and temperature.

Excess pressure occurs if too much refrigerant or refrigerant oil is used, the condenser is contaminated, the radiator fan is malfunctioning, the system is blocked or there is moisture in the refrigerant circuit (icing-up of restrictor or expansion valve).

The evaporator, evaporator temperature sensor and the A/C compressor to separate high and low pressure gas ends are located on the low pressure side.

A drop in system pressure can occur due to loss of refrigerant, restrictor or expansion valve (restrictions), A/C compressor malfunction or iced evaporator.