Page 214 - Handbook of Energy Engineering Calculations

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10,500 ft /min (297.3 m /min).
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The windows provide 2445 ft /min (69.2 m /min), step 4, and the engine
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radiator gives 6000 ft /min (169.9 m /min), step 1, or a total of 2445 + 6000
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= 8445 ft /min (239.1 m /min). Thus, 10,500 − 8445 = 2055 ft /min (58.2
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m /min) must be removed from the room. The usual method employed to
remove the air is an exhaust fan. An exhaust fan with a capacity of 2100
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ft /min (59.5 m /min) would be suitable for this engine room.
Related Calculations. Use this procedure for engines burning any type of
fuel—diesel, gasoline, kerosene, or gas—in any type of enclosed room at sea

level or elevations up to 1000 ft (304.8 m). Where windows or the fan outlet
are fitted with louvers, screens, or intake filters, be certain to compute the net
free area of the opening. When the radiator fan requires more air than is

needed for cooling the room, an exhaust fan is unnecessary.
Be certain to select an exhaust fan with a sufficient discharge pressure to
overcome the resistance of exhaust ducts and outlet louvers, if used. A
propeller fan is usually chosen for exhaust service. In areas having high wind
velocity, an axial-flow fan may be needed to overcome the pressure produced

by the wind on the fan outlet.
Table 6 shows the pressure developed by various wind velocities. When
the engine is located above sea level, use the multiplying factor in Table 7 to

correct the computed air quantities for the lower air density.

TABLE 6 Range of Discharge Temperature *