Simple Modeling to Determine Appropriate Operating Conditions for Emission Testing in Small Chambers

Much of the mass-balance modeling of concentrations produced by indoor sources has been based upon emission rates obtained from small chamber testing. The suitability of emission rates used as inputs to such models is important and can depend upon the operating conditions of small test chambers. However, these operating conditions to date have largely been established on the basis of intuitive choices, that is, what appears reasonable in simulating actual full-scale indoor environments, rather than a critical examination of factors that can affect emissions. In this paper, the consequences of these choices are examined, and this examination suggests that air in chambers, as currently operated, may be stagnant. This indicates the need to measure air velocities under current operating conditions. Suggestions for improving chamber operating conditions are presented that may produce more accurate emission rates.