How should humidity control be evaluated in humid climates during Cx?

• A. Verify dehumidification controls, humidity setpoints, and sensor calibration; test moisture removal performance.
• B. Record only indoor humidity.
• C. Ignore humidity control.
• D. Test only at design temperature.

Answer: (A)

In humid climates, evaluating humidity control during commissioning centers on proving that the system actively maintains indoor moisture at the target level, with accurate sensing and proper responsive control. This means confirming that the dehumidification controls are functioning, the humidity setpoints are appropriate for comfort and condensation prevention, and the humidity sensors are calibrated so readings reflect actual conditions. Beyond just reading relative humidity, you also need to verify moisture removal performance—showing that the system can remove moisture effectively under high-humidity conditions and occupancy loads, and that it engages the dehumidification modes when needed.

Why this approach matters: in humid environments, moisture management is fundamental to comfort, mold prevention, and energy efficiency. If controls don’t respond correctly to rising humidity, or sensors drift, the indoor RH can exceed targets even if a single humidity reading looks acceptable. Testing performance under realistic, high-humidity scenarios ensures the system can meet design goals in the conditions that matter most.

Other options fall short because recording indoor humidity alone doesn’t verify that the control system acts appropriately or that sensors are accurate; ignoring humidity control misses a critical parameter for IAQ and comfort; and testing only at design temperature ignores the real-world humidity swings that drive moisture loads.