whats a good fan size

im gonna run 3 1kwatt hps with an ac unit. whats a good size fan to suck cool air..i have an 8 inch 470cfm fan is that ok...

should be , if not add a booster to the end.

if you put your fan in a cool spot and run ducting with now bends your fine. if you cant run a straight line you will need a bigger fan. adding a booster on opposite end would work but fans work better pushing than pulling air. you also dint want to get your fan to hot by running all that hot air through it. heat kills electric motors over time so i try to avoid pulling air