At least one rotor is a downwind rotor (4), and at least one rotor is an upwind rotor (1).

Upwind and downwind fairings may be used when retrofitting pre-existing buildings.

At least one upwind heat transfer section (81, 91, 92, 95) protruding to the air flow path (40) side is formed on each of the upwind plate sections (77).

Never upwind or downwind, always in the corridors and zigzagging, always at top speed.

On the one hand, this means that the rotor will have a tendency to yaw against the wind automatically, regardless of whether we are dealing with an upwind or a downwind turbine.

Windward and leeward: The side facing the wind is called "windward", the other side is "leeward".

The windward side edge (54a) of the louver fin (54) and the windward side edge (55a) of the louver (55) are respectively formed into a semielliptic cross-sectional configuration which becomes thinner toward the windward side.

An objective of the present invention is to have the apex of a wind receiving body consistently face windward.

The size of the clearance is set to unite a water drop adhering to the lee side end of the windward corrugated fin and a water drop adhering to the windward end of the leeward corrugated fin.

Weather side: The windward side (from where the wind is blowing).