Wind-Driven Rain, Air Pressure, and Windows

Drainage is the key to life in general and pressure equalization—if it applies at all—is for joints and not for entire wall assemblies. Claddings need to be drained. Ventilated if you must, but first and foremost they need to be drained. Whereas joints in insulated glazing units, pre-manufactured windows both residential and commercial, joints in precast panels and connections between windows and wall assemblies can be pressure equalized but regardless they have to be drained.