Tiny Cooling Fan how to judge how the wind?

Galvanized square "Tiny Cooling Fan" blinds at the outlet, so severely increased wind resistance, the wind not to spread around, but by the louver diversion concentrated blowing in the same direction. When a person standing in front of the fan outlet to the left side of the fan air volume is significantly greater than the right, which is due to the design of the duct and the fan caused by the defect.
FRP flared "Tiny Cooling Fan" mainly to see the situation blinds open and the bell out of the wind situation. Look at the following two main venetian blinds open, the bell every part of the wind out of the wind should be the same size, the center and the edge of the wind as large wind evenly spread around.
FRP square "Tiny Cooling Fan" of air volume is minimal. The open square suction fan righting fiberglass frame floor, while the wind while the wind situation is more obvious than the small square galvanized sheet suction fan, the opportunity to place wind clockwise.