CONTRIBUTION OF OUTDOOR NITROGEN DIOXIDE ON INDOOR AIR QUALITY OF ROADSIDE STORES USING INDOOR MASS BALANCE

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. In the present paper, penetration factor and source strength factor were calculated using multiple indoor and outdoor measurements with roadside stores (5 restaurants, 5 coffee shops, and 5 convenience shops). To estimate the contribution of outdoor air NO2 on indoor air quality of roadside stores, daily indoor and outdoor NO2 concentrations for roadside stores in spring and summer were measured for 21 consecutive days. Subsequently, mean contribution of outdoor NO2 sources on indoor air quality of each store were different, suggesting that both indoor and outdoor sources had contributions to indoor NO2 concentrations. This method might indicate that contribution of outdoor air on indoor air quality without ventilation rate and decay rate measurements could be estimated by multiple measurements.