If excess refrigerant is charged into a system, the result is typically

• A. No effect on efficiency
• B. Decreased compressor speed
• C. Decreased head pressure
• D. Reduced overall efficiency due to higher head pressure

Answer: (D)

Overcharging a refrigeration system with refrigerant increases the amount that must be compressed and circulated. This extra refrigerant raises the pressure on the high side (head pressure) in the condenser. When head pressure is higher, the compressor has to work harder to push the refrigerant through the system, which increases power consumption and lowers the system’s overall efficiency (COP). Higher head pressure can also lead to higher discharge temperatures, further reducing efficiency and stressing components. So the typical result of excess refrigerant is reduced overall efficiency due to higher head pressure.