Engine Room Ventilation - Perkins 415GM Installation Manual

N38143
The engine room must be ventilated for two reasons:
•
To supply the engine with air for combustion.
•
To provide a flow of air through the engine room to prevent an excessive temperature build up, which
may cause components such as the generator to overheat.
In most applications in temperate climates, the engine will draw air from the engine room. If this is the case
then, as a rough guide, it can be taken that every horsepower produced by the engines requires, as a minimum,
0.25 sq.ins. of vent area. If the boat is likely to be used in hot climates, and if engine room ventilation fans
are fitted, then a vent area of 0.5 sq.ins. per horsepower should be provided, (see the table below). Wherever
possible a flow of air through the engine room should be encouraged by using forward facing intake vents to
take advantage of ram airflow, together with other vents to allow hot air to escape.
With an effective ventilation system the engine air intake temperature will be no more than 10 Centigrade
degrees higher than the outside air temperature.
Engine
415GM
422GM
422TGM
700GM
4GM
4TGM
4.4GM
4.4TGM
4.4TWGM
4.4TW2GM
6TG2AM
6TWGM
Note: This is in addition to the ventilation needs of the main propulsion engines.
Minimum cross section of air duct per engine
For hot climates
103sq.cm (16sq.ins)
135sq.cm (21sq.ins)
200sq.cm (31sq.ins)
348sq.cm (54sq.ins)
213sq.cm (33sq.ins)
275sq.cm (42.6sq.ins)
358sq.cm (55.5sq.ins)
474sq.cm (73.5sq.ins)
477sq.cm (74sq.ins)
626sq.cm (97sq.ins)
Engine room ventilation
For temperate climates
52sq.cm (8sq.ins)
71sq.cm (11sq.ins)
103sq.cm (16sq.ins)
174sq.cm (27sq.ins)
106sq.cm (16.5sq.ins)
139sq.cm (21.5sq.ins)
181sq.cm (28sq.ins)
240sq.cm (37sq.ins)
240sq.cm (37sq.ins)
316sq.cm (49sq.ins)
Chapter 1
Page 1