It is important to know that pusher fans with straight blades must be spaced out ¼” from core or fan mount fans. If a pusher fan attaches onto AC condensers should be attached with plastic ties that are cut off at the condenser. You should never put plastic ties through the radiator because it could cause the radiator to leak.
Pusher fans should be the same diameter or smaller than the air conditioning condenser. A larger fan can cause air to pass through the open area. Although you can use two small fans, one large fan 14” – 16” typically works better. If you are able to use two pusher fans, 12″ or larger, two fans generally work better than using only one large fan. When the pusher fan is a helper, one 11″ or larger fan will work best. You can use two 10″ or smaller fans if you have room. When a pusher fan is the only fan being used, select a fan or fans that will cover up as much of the core as possible.