154 COMMERCIAL ELECTRICAL TESTING; 



= 4015V / /^for Std. Air. 



Ik" 1 



Vol. =1097\/--XA^4 

 V w 



for A' = 0.91 : 

 = 3774XAVV" for A' = 0.94: 



for Std. Air. 



K =0.94 for the Cone Method. 

 K =0.91 for double Pitot tube or Navy method. _ 

 For a given opening pressure varies as the square of 

 the speed of the blower. 



Volume varies as the square root of the pressure, 

 hence, directly as the speed. 



Air horse power varies as the cube of the speed. 



T^-CC T^rc Air horse power 



Eff . = Efficiency = --- = 



r an horse power 



