Wind Pressures on Open Rain Screen Walls: Place Air Canada

Wind pressure differences are measured across the rain screen and across the air barrier assembly of precast open rain screen wall panels. Twelve panels are instrumented mostly on the west, north, and east walls of the 24th floor of a 27‐story office building in downtown Montreal. 32 channels were scanned at 30 times per second to allow reasonable resolution of peak gusts. However, some doubt remains about their spatial extent, as each $3.6\times 2.9m(11.8\times 9.5\mathrm{ft})$ panel had only one external tap. The maximum load measured on the rain screen in one year of continuous monitoring was 285 Pa (6 psf), of duration 1 second. The largest pressure difference across an entire panel of the uilding envelope never coincided with peak pressure differences on the rain screen. However, maxima due to wind only, across windward panels, ranged from 400–475 Pa (8.4–9.9 psf). Pressure differences across the air barrier assembly of wall panels included stack and heating, ventilating, and air conditioning (HVAC) effects of up to 150 Pa (3.1 psf) when outside temperatures dropped to $-20°C$ $(-4°F)\text{.}$