# Appendix G Example Calculation of Outdoor Air Rate

### G101.1 Example Calculation

Determine the outdoor air rate required for a single zone AC unit serving an interior 2000 square feet (185.81 m2) conference/meeting room with a design occupancy of 100 people. The system supplies and returns air from the ceiling. (See Chapter 4 of this code for guidelines)

Solution:

In accordance with Table 403.2.2, the zone air distribution effectiveness is 1.0 since the system supplies cooling only from the ceiling. Using the rates from Table 402.1 for a conference/meeting room, the minimum system outdoor air rate is calculated to be:

(Equation G 101.1)

Where:
 Az = zone floor area: the net occupiable floor area of the zone in square feet. Pz = zone population: The largest number of people expected to occupy the zone during typical usage. Where the number of people expected to occupy the zone fluctuates, Pz shall be permitted to be estimated based on averaging approaches described in Section 403.6.1. Where Pz cannot be accurately predicted during design, it shall be based on occupant density in accordance with Table 402.1. Rp = outdoor airflow rate required per person in accordance with Table 402.1. Ra = outdoor airflow rate required per unit area in accordance with Table 402.1. Ez = zone air distribution effectiveness in accordance with Table 403.2.2.
For SI units: 1 square foot= 0.0929 m2, 1 cubic foot per minute = 0.00047 m3/s
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