In a condenser system, energy balance states total heat rejected equals heat picked up in evaporator plus heat of compression. Which statement describes this energy balance?

• A. The Heat Rejected by the Condenser equals the Evaporator Heat Plus Compression Heat
• B. The Evaporator Heat is Rejected Directly Without Compression
• C. The Condenser Heat equals Ambient Heat Gain
• D. The Energy Balance Is Inaccurate

Answer: (A)

In a basic vapor–compression refrigeration cycle, the first-law energy balance for the loop tells us that energy out of the condenser must equal the energy in to the evaporator plus the work put into the compressor. The evaporator removes heat from the space being cooled and transfers that heat to the refrigerant, and the compressor adds energy to the refrigerant (the work input). Therefore the condenser must reject the sum of those energies to the surroundings. That’s why the heat rejected by the condenser equals the heat picked up in the evaporator plus the heat of compression. For example, if the evaporator handles 4 kW of heat and the compressor adds 1 kW of energy, the condenser must reject 5 kW. The other statements don’t describe the actual energy flow in the cycle: evaporator heat isn’t rejected directly, condenser heat isn’t tied to ambient heat gain, and the energy balance is valid for steady operation.