- Coolant charge: lack of refrigerant causes pressure reduction and excess refrigerant causes an increase in the discharge pressure;
- External Temperature: the lower the external temperature the lower the
suction for the same refrigerant charge;
- Air flow in the condenser: any obstruction to the passage of air in the condenser will cause an increase in the discharge pressure, for example: dirty condenser, short circuit of air, broken propeller, for the same charge of refrigerant;
- Loss of load on the expansion device: if the expansion device causes
pressure drop above the design, for example: piston with smaller diameter, the
discharge pressure will be high.
- Obstruction in the system: if there is any type of internal obstruction in the system
caused by dirt (eg dirty screen filter), the discharge pressure will
increase.
