Thermal Comfort and Sound Environment
What the exam tests
This domain combines two comfort drivers that are measured separately but experienced together. Expect questions on ASHRAE 55 thermal comfort, zoning, acoustical metrics, and the difference between background noise and reverberation.
Core rules
- Thermal comfort is a function of air temperature, radiant temperature, humidity, air speed, clothing, and metabolic rate. ASHRAE 55 uses PMV/PPD and adaptive approaches; a single thermostat setpoint does not prove comfort.
- Provide thermal zoning for differing exposures and uses, individual control where feasible, and monitoring that reflects occupied conditions.
- Acoustics: dBA or NC/RC describes background noise; reverberation time describes how sound persists; sound masking and absorption address speech privacy.
- WELL sound features often require a sound map, maximum noise levels, HVAC background-noise limits, and impact-noise control.
Worked example
Occupants near a rooftop air handler complain of fatigue and difficulty concentrating. A sound-level meter reads 48 dBA, above the design goal of 35 dBA for the open office. Adding carpet would reduce impact noise but not the steady HVAC rumble. The reasoning points to vibration isolation, duct lining, and a properly sized air handler; measure again at the occupied location.
Traps
Treating a thermostat reading as proof of thermal comfort. Using dBA alone to assess low-frequency HVAC noise. Confusing absorption with blocking. Measuring acoustics in an empty room and comparing directly with occupied conditions.