Cooling Fans

• When would I use a cooling fan?
• I am installing a device that uses a propeller fan near a wall. How far away should the fan's outlet or intake be from the wall?
• If the fan does not have an earth terminal, how can I ground it?
• I would like to change the wiring of the blower so that the suction port and discharge port are reversed. Is this possible?
• When using multiple fans with the same noise level, is there a way to calculate the total noise level?
• Is there a way to tell when the fan motor has stopped?
• Is it possible to reverse the rotation of the AC Propeller Fan MRS series fans?
• How do I calculate the air speed of a fan?
• For ventilation cooling, where is the best place to install the fan?