Provide for Additional
Outdoor Air Supply Quantities in Future
ASHRAE
Standard 62-1989 Table 2 sets minimum outdoor air supply rates
for different occupancies, intended to ensure that the majority
of occupants express no dissatisfaction with odors or experience
sensory irritation. They are not intended to establish ventilation
rates that ensure occupant health. The ASHRAE Standard 62-1989
outdoor air supply rates should be considered as minimum outdoor
air rates supplied by mechanical systems.
Design
supply air systems to allow the future supply of 150% of the
outdoor air supply required by ASHRAE Standard 62-1989 Table
2. Wherever possible, provide additional outdoor air capacity
in the supply air system to allow for future changes of occupancy,
pollutant sources not known during design, and individuals
with environmental sensitivities. Size outdoor air intake
louvers and ductwork for this additional capacity, and provide
space for future addition of coils, drain pans and equipment
to condition this amount of air.
If air-side
economizers are specified, this capacity is already inherent
in the design. With the ability to provide large quantities
of outdoor air, night ventilation can be used to precool building
mass. This can have significant energy benefits.
Caution
- Additional
space in equipment rooms for intakes and coils may be required.
May require more equipment room, duct or shaft space.
