1. The total volume of air in a system, which is a combination of the air brought into the system from the outdoors and the air that is being recirculated within the building. 2. The fresh air brought into the system from the outdoors.
Table 2.2 of ASHRAE Standard 62-1989-- Ventilation for Acceptable Indoor Air Quality--recommends a minimum ventilation air quantity of 20 cubic feet per minute (cfm) per person in laboratories.
Defined as the total air, which is a combination of the air brought into the system from the outdoors and the air that is being recirculated within the building. Sometimes, however, used in reference only to the air brought into the system from the outdoors.
Defined as the total air, which is a combination of the air brought inside from outdoors and the air that is being re-circulated within the building. Sometimes, however, used in reference only to the air brought into the system from the outdoors; this document defines this air as "outdoor air ventilation."
That portion of supply air that comes from the outside (outdoors), plus any recirculated air that has been treated to maintain the desired quality of air within a designated space.
That portion of supply air that is drawn from outside, plus any recirculated air that has been treated to maintain a desired air quality.