An air conditioning system that is oversized can cause...

• A. Higher energy efficiency
• B. Inefficient dehumidification of the conditioned space
• C. Faster cooling with less energy
• D. Reduced comfort

Answer: (B)

When an air conditioner is oversized for the space, it tends to short-cycle: it starts cooling, reaches the set temperature quickly, and then shutting off before moisture has a chance to be removed from the air. Cooling is only part of what an AC does—the other important part is dehumidification. The evaporator coil becomes cold enough to condense moisture from the air, but that effect relies on the system running long enough. Short cycles mean the coil doesn’t stay in contact with the air long enough to dehumidify effectively, so the space can feel damp or clammy even though the temperature is comfortable. That’s why the correct choice points to inefficient dehumidification of the conditioned space.

Other options aren’t as accurate. The issue isn’t that you gain higher energy efficiency; the frequent starts and short runs can actually waste energy and leave humidity higher. The idea of faster cooling with less energy isn’t accurate in practice for an oversized system, since the energy used during those short cycles and restart losses isn’t genuinely lower. And while reduced comfort can result, the specific problem caused by oversizing is the poor moisture removal, which is why inefficient dehumidification is the best description.