I am currently studying electronics and had an idea that you can reverse the rotation of an electric motor that can be used in a wide variety purposes. For example, an electric fan’s motor rotation can rotate clockwise AND counter-clockwise without any mechanical but pure electronics. By reversing the polarity of an electric charge, the motor will rotate in a reversed motion. Practically, this can be applied in electric fans and serving also as an exhaust fan.
Another idea is to use a remote control to the fan, for the customer’s convenience sake. Funny, because this is used primarily on children’s toys like remote controlled cars or RCs.
Here is a render of the electric/ exhaust fan with remote control:
Note: I used 3D Rota-aire design as basis.
I have to point out from the render that the rotation of the grills is different from the rotation of the electric motor.