# Fan Speed Formula

Is there any formula for computing fan speed by using air mass,air flux, air density or specific heat? I have computed air mass and air flux, and found the values for air density and specific heat, but now I am stuck at finding a correlation between these and fan speed.

• Can you reproduce your computing here much appreciated – user6760 May 18 '15 at 12:20
• I start from 2 equations for computing the power consumption of a data center: P = mCp*(Tout-Tin) and P=pf*Cp(Tout-Tin), where m=air mass, Cp= specific heat, p=air density (1.205kg/m^3 at 20degreesC),f= air flow rate = m/p, Tin = the inlet temperature (temperature supplied by a CRAC unit), Tout=exhaust temperature. I also know that the fan power Pfan=(FanSpeed^3) (equation 3). What I need, is to find a correlation between the first 2 equation and the 3rd one – Ade May 19 '15 at 10:05
• The fan laws state that the air flow is proportional with the fan speed. So, basically, I need to convert airflow (m^3/s) to speed – Ade May 19 '15 at 13:54