This is a fan assembly designed to be used as a moving agricultural vehicle for use in conveying cold air, to form a flat floor with a hydraulic lifting arm, to provide a measure against frost damage on crops. The fan has a propeller head and rotatable blades. The propeller head allows air to be directed to a specific area of the product. The machine has a handle that can rotate in the desired angle range relative to the base, which preferably provides a lateral and vertically adjustable movement of the propeller head and the blades and is preferably in contact with the floor. In order to provide significant protection against frost damage, the propeller head is positioned, so as to blow the air into the desired area.