Various approaches to air sampling for air-quality monitoring are compared and evaluated. The approaches discussed include grab-sampling walkthroughs, data-logging monitors, distributed wall-mounted monitors, and multipoint shared-sensor approaches. Among these options, the most representative and comprehensive data are provided by the multipoint shared-sensor approach. Under this approach, the more detailed information on the heating, ventilation, and air-conditioning (HVAC) system extends beyond just screening to evaluate the sufficiency of ventilation and gets into other aspects of performance. The monitoring of carbon dioxide (CO ₂ ) concentrations, for instance, can provide feedback on the uniformity of ventilation, the effectiveness of the overnight purge, the occurrence of reentrainment, or the capture of air contaminants from nearby vehicles. If the monitoring of humidity is included in this approach, feedback on humidity control and the presence of moisture sources also becomes available. This shared-sensor approach to sampling in buildings, therefore, can provide important information on HVAC performance in the areas of ventilation, infiltration, and moisture control. As such, it can improve the management of buildings by reducing the amount of uncertainty in this performance.

Units: I-P