Determination of Wind Load
Wind loading is determined by either reference to relevant building codes
or through specific modeling in a boundary layer wind tunnel (BLWT). The
characteristics of each approach are summarized below:
Glass and Metal
PERFORMANCE Curtain Walls
Code Derived Wind Load – Features and Limitations
• NBCC provides relatively simple procedures for calculating wind
load based on building height, shape and location.
• Total load to be resisted by wall is the algebraic sum of external and
internal pressures.
• Formulae are provided to calculate external and internal pressures,
with special factors included for the design of cladding elements.
• Reference wind velocity pressure for cladding design is based on a
probability of being exceeded in any single year of one in ten.
• Procedures only truly apply to regular rectangular shaped buildings.
Do not identify peak corner or hot spot load locations. Tend to
overestimate positive pressures and underestimate negative pressures
on high rise buildings. Do not account for special conditions such as
crosswind deflection, vortex shedding or instability due to flutter or
galloping.