How do the tables in ASHRAE 62.1 influence VRP calculations?

• A. They set maximum humidity levels for spaces.
• B. They specify the exact fan energy consumption.
• C. They define room temperature setpoints.
• D. They provide baseline outdoor air requirements by space type or occupancy.

Answer: (D)

Outdoor air rates from ASHRAE 62.1 tables establish the baseline ventilation required for each space. Those tables specify outdoor air per occupant and outdoor air per unit area by space type, which you use in the ventilation rate procedure to determine the required outdoor air flow for a space. In practice, you multiply the per-person rate by the number of occupants and the per-area rate by the space area, and the greater of those two results becomes the outdoor air that must be delivered to meet the design. This is why those tables directly influence VRP calculations. The other options don’t govern the VRP: humidity limits, exact fan energy, or room temperature setpoints are handled in other aspects of design or comfort strategies, not the baseline outdoor air requirements used in VRP.