Automated air infiltration measurements in large buildings.

An automated air infiltration measurement system for large buildings isdescribed. The system consists of a micro-computer, electron capture gaschromatograph, a ten port sampling manifold, and five tracer gas injectionunits. The system controls the injection and sampling of tracer gas in amulti-zone building, calculates the air infiltration rates of each zone, andmeasures the on-time of events such as HVAC fan operation, exhaust fan operation,and door/window openings. The measurements also include such analogvariables as interior and exterior temperatures, wind speed, wind directionand pressure differentials across the building envelope. The data collectedusing the automated air infiltration system in large buildings will allowthe determination of the relative importance of air leakage and forced ventilationon the energy requirements of the building, as well as evaluating theinfluence of meteorological conditions, HVAC fan operation, exhaust fanoperation and exterior building pressure on the air leakage.