The system of heat balance which we are using on the board ship is that of forced ventilation.
The forced ventilation is carried out by means of a fan which is driven by electric motor (usually three phase). The purpose of utilizing three phase fan is because it can be rotated clockwise or counterclockwise by changing two phases(usually by magnetic contactor, combination of relay and timer).
The heat which is produced by the various machineries such as the main engine, aux. generators, boiler, pumps, motors, incandescent lights, fluroscent lights, and other ancillaries things adds on to produce the overall heating effect and raising the temperature inside the engine room. In replacement cool air replaces the warm air thus maintaining balance.
During voyage and in harbour it is necessary to keep good ventilation in our engine room, which will result in good efficiencies of machinery in the engine room.
Also it helps us to lower the Ambient temperature (temperature of surroundings) of the engine room. Thus maintaining a good working atmoshpere inside the engine room.
The other purpose of this forced ventilation system is to provide air in case of turbo blower and turbocharger failure for the natural aspiration of Main Engine and in case of total flooding of Engine Room (E/R) the vent is used in reverse to remove carbon dioxide from the engine room.