out let is more important.it would not use more amps ,it would use less.{if intakes to small}-fan would stall or cavate.area is important.non turbulant air flow is a must.inlet must have a good, lip radius, to promote good flow. a big inlet with turbulant flow ,will cut flow in half.once in flight,the game changes. now you have some forced air to help.. 80 % fan area for exhaust size..RALPH