Noncondensable gases in the refrigeration system can cause which of the following?

• A. Increased high-side pressure
• B. Decreased high-side pressure
• C. Higher COP
• D. Faster cooling

Answer: (A)

Noncondensable gases in a refrigeration system don’t condense in the condenser and tend to collect as a gas layer. That layer hinders heat transfer from the refrigerant to the condenser, so the condenser must operate at a higher pressure to reject the same amount of heat. The compressor then works against this higher pressure, raising the high-side (discharge) pressure. This is the direct, primary effect.

Because the system has to work harder to reject heat, efficiency drops and cooling is not faster; the COP decreases and heat removal slows. The other options would imply lower head pressure, higher efficiency, or faster cooling, which don’t happen when noncondensables are present.