Condenser capacity is typically sized to be what percent larger than the evaporator in a system?

Condenser capacity is typically sized to be what percent larger than the evaporator in a system?

• A. 25
• B. 20
• C. 15
• D. 10

Answer: (A)

The main idea is that the condenser must reject more heat than the evaporator absorbs because the compressor adds energy to the refrigerant. In steady operation, the heat rejected by the condenser equals the heat absorbed by the evaporator plus the work put into compression: Q_cond = Q_evap + W_comp. Since compressor work is significant, the condenser capacity ends up larger than the evaporator’s. A common design guideline is about 25% more capacity for the condenser to account for this added heat and typical losses, providing the necessary margin for heat rejection. Smaller margins (20%, 15%, or 10%) wouldn’t fully compensate for the work and losses, risking inadequate heat rejection and higher system pressures.

The main idea is that the condenser must reject more heat than the evaporator absorbs because the compressor adds energy to the refrigerant. In steady operation, the heat rejected by the condenser equals the heat absorbed by the evaporator plus the work put into compression: Q_cond = Q_evap + W_comp. Since compressor work is significant, the condenser capacity ends up larger than the evaporator’s. A common design guideline is about 25% more capacity for the condenser to account for this added heat and typical losses, providing the necessary margin for heat rejection. Smaller margins (20%, 15%, or 10%) wouldn’t fully compensate for the work and losses, risking inadequate heat rejection and higher system pressures.