Cooling Tower Fans This high value power saving is not possible in all fans of all the sizes, it depends on how far away the working fan is operating from the b. e. p. and the value of efficiency at b. e. p. Owing to our vast experience, we have been able to specify a minimum guaranteed power saving of 15% or increase in air flow of about 10% with our fans of 3.00 m diameter and above as compared to existing conventionally designed fans.