Proper Ventilation

The second pillar of world class indoor air quality (IAQ) environments is proper ventilation. The ASHRAE Standard 62-2001 offers two methods of determining the amount of outdoor air required to properly ventilated indoor occupied spaces for acceptable IAQ: the Ventilation Rate Procedure and the IAQ Procedure. The Ventilation Rate Procedure is described in Section 6.1 of ASHRAE Standard 62-2001. The IAQ Procedure is described in Section 6.2 of the Standard. A brief description of the ventilation Rate Procedure is given below. More details and a description of the IAQ Procedure can be found by downloading the Standard 62-2001. The following table from the Environmental Protection Agency (EPA) is provided for reference.

Ventilation Rate Procedure

Step 1: Determine the quality of the outdoor air. The designer cannot simply assume that the quality of the outdoor air surrounding the building is acceptable for use as ventilation air. The "EPA National Ambient-Air Quality Standards for Outdoor Air" tables for particulate and gaseous contaminants should be referenced and particulate and/or gaseous filtration is necessary if the threshold levels for these contaminants are exceeded.

Step 2: If the outdoor air is unacceptable, the standard advises that it be cleaned of filtered.

Step 3: Determine the amount of air required in each space and install the appropriate HVAC system.

Section 6.1.3 of the ASHRAE Standard 62-2-1 states:
"Indoor air quality shall be considered if the required rates of acceptable outdoor air in the table are provided for the occupied space."