A number of interzonal air flow models have been developed to calculate air flows and pollutant transport mechanisms in both single-zone and multizone buildings. The International Energy Agency's Energy Conservation in Buildings and Community Systems program adopted a working group on multizone air flow modeling to study physical phenomena causing air flow and pollutant transport (e.g., moisture) in multizone buildings, develop numerical modules to be integrated into COMIS, and evaluate the computer code.
Energy saving measures with reduced outdoor air change rates may lead to critical indoor air contaminant concentrations. Emission characteristics of construction materials and products play an important role. Therefore a project has been set up at EMPA to investigate emission characteristics of such materials using test chambers.
A comprehensive theory of multi-chamber air infiltration measurement using a single tracer gas is introduced from the general stand point of system identification. The thermal network model can be applied not only to the temperature transfer and diffusion system but also to the tracer gas transfer system. This model is formulated mathematically in a stale equation. The coefficents in the state equation represent airflow rates of infiltration. Two theories for estimating these coefficients are deduced from the least square.