Question

A 75-hp (shaft output) motor that has an efficiency of 91.0 percent is worn out and is replaced by a high-efficiency 75-hp motor that has an efficiency of 96.3 percent. Determine the reduction in the heat gain of the room due to higher efficiency under full-load conditions.

Answer 1

4.536hp

Step-by-step explanation:

The decrease in the heat gain of the room is determined from difference in electrical inputs:

`Q = W_(shaft) ((1)/(n_(1) ) - (1)/(n_(2) ))\\Q = (75hp)*((1)/(0.91 ) - (1)/(0.963 ))\\\\Q = 4.536 hp`