A sensitivity study of parameters in the Nazaroff-Cass IAQ model with respect to indoor concentrations of O-3, NO, NO2.

The indoor O-3, NO, NO2 concentrations and their corresponding indoor/outdo or (I/O) concentration ratios are predicted in this paper for some represen tative buildings, using the Nazaroff-Cass indoor air quality model. This pa per presents and systemizes the relationship between indoor air pollutant c oncentrations and the building's design, use and operation. The building pa rameters which are determined to be main factors affecting the air pollutan t concentrations are: the physical dimensions of the building and the mater ials of construction, the building's air exchange rate with outdoors and th e indoor air pollutant sources. Changes of ultraviolet photon fluxes, of te mperature and of relative humidity indoors, have little effect on indoor O- 2, NO and NO2 concentrations, for air exchange rates above 0.5 ach. Special attention must be given when a building has a very low air exchange rate, under which conditions the effect of a small change in any of the factors d etermining the indoor air quality of the building will be much more noticea ble than in a building with a high air exchange rate.