Marine Installation Manual
2021-08
4-94
4 Ancillary Systems
4.10 Engine room ventilation
X72DF
4.10.2
Ventilation arrangement
It is important to follow the best practice methods for supplying the combustion
air for main engine as described in this section. However, the final layout of the
engine room ventilation is at the discretion of the shipyard.
Two different
ventilation arrangements
Experience shows that the air flow in the engine room, from the ventilation
system outlet to the turbocharger inlets, should be as direct as possible. This in
-
creases the amount of air directly supplied to the turbocharger, limiting heat
transfer to the air flow and therefore providing the best possible engine perfor
-
mance, especially during tropical conditions.
Alternatively, a ventilation system with a direct air suction layout can be ar
-
ranged, where the ventilation system connects the outside ambient air directly to
the engine.
These two different arrangements are discussed as follows:
•
Arrangement 1
— Engine room ventilation system (
The ventilation system draws air from the outside ambient air into the en
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gine room, where it is sucked into the turbocharger inlet.
•
Arrangement 2
— Direct engine ventilation system (
The ventilation system outlet is connected to the turbocharger inlet. There
-
fore, the outside ambient air is sucked directly into the turbocharger
without passing through the engine room.
NOTE
In both arrangements, the ventilation inlets must be located and de
-
signed to ensure that water spray, rain water, dust and exhaust gases
cannot enter the system nor the engine room.
