Intent 1:
To limit the probability of using inappropriate
wind load assumptions, which could lead to the deflection, movement
and deterioration of required environmental separation elements subject
to wind load, which could lead to the failure of such elements, which
could lead to the inadequate control of:
- the total heat loss or gain due to air mass transfer
or conduction,
- air infiltration and exfiltration,
- airborne vapour transfer from the interior above ground
and from the exterior below ground,
- precipitation ingress due to air pressure differences,
or
- condensation.
This is to limit the probability of:
- the inadequate control of temperatures of interior spaces,
drafts, relative humidity, or water accumulation,
- pollutant ingress, including soil gas, combustion products
from parking garages, and particulates,
- the generation of pollutants from biological growth
or from materials that become unstable on wetting, or
- deterioration, which could lead to compromised integrity
of environmental separators.
This is to limit the probability of:
- negative effects on the air quality of indoor spaces,
- the inadequate thermal comfort of persons, and
- contact with moisture.
This is to limit the probability of harm to persons.
Intent 2:
To exempt certain environmental separation elements
from the requirement to be designed for 100% of the specified wind
load, where tests or analysis have demonstrated that certain elements
will be exposed to a lesser specified wind load.