ABSTRACT
The determination of the outdoor air (OA) quantity entering the heating, ventilation, and air conditioning (HVAC) system is an important starting point in a ventilation-based indoor air quality (IAQ) evaluation. If the IAQ investigation is not being performed on a proactive basis, the first step in the evaluation process is to identify the historic issues of concern and complaints of the occupants of the building. The occupants are important sources of information about the functioning of the HVAC system due to the amount of time these people have spent in the building compared to the amount of time typically available for the investigator. In making the determination of the OA quantity that is being drawn into this HVAC system, consideration should be given to the qualitity of outdoor air. Beyond the intentions of the design, the details of the actual installation also affect the ability of the HVAC system to deliver adequate quantities of outdoor air to the building occupants.
