01
Baseline measurement
Two to four weeks of continuous CO₂, PM2.5, TVOC, temperature and humidity at breathing-zone height across representative zones.
02
Ventilation check
Measured supply at terminals. AHU fresh air fraction. Filter condition and pressure drop. Damper and VAV operation.
03
HVAC hygiene
Coil cleanliness, condensate management, humidifier condition, ductwork dust deposit to TR/19, intake location and protection.
04
Indoor sources
Material specifications since last review, printer and copier siting, cleaning product VOC content, food and waste handling.