A set of methods and apparatus for efficiently pressurizing and ventilating an air-supported greenhouse or other structure requiring pressurization and ventilation. A method for efficiently pressurizing and ventilating an air-supported structure comprises directing any external wind flow and external wind pressure into mechanical flow means, such as a fan, or fans in parallel, operating in the intake direction, and into the internal space of the air-supported structure and out of the internal space of the air-supported structure through internal pressure regulating exhaust means, whereby the internal space of the structure will be ventilated and pressurized with the assistance of any external wind and the reliability of mechanical flow means (fans). This method allows for the efficient, effective, and economical cooling, through ventilation, of a protected space created by a light permeable membrane (cover), which is supported only by internal air pressure against the weight of the membrane and dynamic pressu
