A downdraft fan assembly mountable on a vehicle roll bar, which may be used for providing a flow of ambient air over the vehicle operator, and a canopy carried by the fan assembly, which may be used for providing solar and precipitation protection for the operator. The downdraft fan may draw air through a roof cap with a rear-facing outlet, or may draw air through a series of vents disposed around the canopy of the assembly, or through some combination of the two, such as may be desired. In some variations, multiple openings may be provided in the roof, if desired.