PUMP ROOM VENTILATION
Example:
50kW diesel pump with an overall efficiency of 45% in the said room.
The required ventilation
First thing first, we will determine the minimum air required for combustion ~ 0.1 m3 of
air/min/brake kW (2.5 ft3 of air/min/bhp).
So, the minimum combustion air required ~ 0.1 m3 of air/min/brake kW x 37kW ~ 4 m3/min ~ 240
m3/hr ~ 67L/s.
Next, the heat generated is approx 45% x 50kW ~ 22.5kW; some heat will be discharged as flue and
mostly removed through the radiator.
The permissible room temperature rise depends on the ambient as well as the maximum room
temperature that will not cause component failure. Most modern electronic boards have a max
temperature rating between 50 to 55°C; let’s err on the safe side using 55°C.
And suppose design ambient temperature is 38°C, our permissible room temperature rise is 12K.
Ventilation rate required ~ 22.5kW/(1.099 kg/m3 x 0.017 kW.min/kg.K x 12K) + 5 m3/min ~
105.5 m3/min ~ 6,300 m3/hr ~ 1,750 L/s. This will be approx 120 air change per hour.
Note: In many industrial ventilation designs, we use 5°C and a maximum ambient temperature of
44°C. The maximum permissible room temperature is 49°C. And under many circumstances, we aircondition these rooms.