The standard allows designers to apply the IAQP in some zones within a system, and the VRP in other zones, and it requires designers to document design assumptions and calculations, but here we focus on the nine steps listed.
Designers must also consider mixtures-of-concern to comply with the IAQP.
Most designers using the IAQP don't identify impact mixtures--they simply focus on the concentration limits for specific contaminants, and assume they need only introduce the OA needed for the "worst-case" contaminant.
After completion of design, construction and installation, but prior to full operational occupancy, a subjective evaluation must be conducted in each IAQP zone.
The higher of these two values establishes the minimum breathing zone OA rate for each IAQP zone.
The IAQP is a valid procedure that has apparently been successfully applied to design ventilation systems in some buildings, especially where the same building design with substantially similar zones is repeated in multiple locations.