Question

Noncondensables in a system cause a: _________.

a) lower suction pressure
b) higher suction pressure
c) lower discharge pressure
d) higher discharge pressure

Answer 1

Noncondensables in an HVAC or refrigeration system lead to a higher discharge pressure due to their inability to condense, which results in increased system pressure and potential efficiency loss.

Step-by-step explanation:

Noncondensables in a system cause a higher discharge pressure. Noncondensable gases, such as air, can enter a refrigeration or HVAC system during servicing or through leaks. These gases don’t condense at the operating temperatures of the system and thus accumulate in the condenser. The presence of noncondensables increases the overall pressure in the condenser because they take up space that would otherwise be filled by condensable gases, leading to a decline in efficiency. As the pressure goes up, the system has to work harder to achieve the desired temperature, which can cause an increased discharge pressure, and could potentially lead to system failure if not addressed.