VAV systems and outdoor air.

HVAC system outdoor airflow rates are usually measured and set at the air-handling unit. The effectiveness of an HVAC system at delivering the outdoor air to the occupied spaces of a building is varied and often disputed. To investigate the delivery of outdoor air to the occupied spaces of a variable-air-volume system, ASHRAE Technical Committee 9.1, Large Building Air Conditioning Systems, funded Project 687- TRP, Minimum Ventilation Airflow Rates with VAV Systems. This article presents some of the information collected during that project.