Engine Room Ventilation - Volvo Penta D1-13 Installation Manual

Engine room ventilation

Two main conditions must be met:
1. The engine must receive enough air (oxygen) for
combustion of the fuel.
2. The engine room must be ventilated, so that the
temperature can be kept down to an acceptable
level.
Ventilation is also important to keep the engine's
electrical equipment and fuel system at a low temper-
ature, and to ensure general cooling of the engine.
NOTE! All valid safety regulations and legal require-
ments for each country must be followed. Each clas-
sification society has its own regulations that must be
followed when required.
The temperature of the inlet air at the air filters must
not be higher than +25°C (77°F) for full power output.
During sea trials the air temperature in the air filter
should not exceed 20°C (36° F) above ambient tem-
perature.
The temperature of the engine itself is rather high in
some places. Certain separate electric components,
such as charging regulators and relays, should there-
fore be fitted on bulkheads or elsewhere where the
temperature is relatively low.
The maximum temperature for areas where electric
components are fitted is 70°C (158°F). The starter
motor and alternator however, have their given loca-
tions.
NOTE! The total intake area can be calculated by us-
ing the formula:
Total intake area = Engine air consumption + Engine room ventilation
Area in cm²
Engine air consumption
The engine consumes a certain amount of air in the
combustion process. This requires a minimum inter-
nal area in the air supply ducting.
The area can be calculated by using the formula:
A = 1.9 × engine power output
A = Area in cm²
Engine output in kW
The value applies for non-restricted intake and up to
1 m (3.3 ft) duct length with only one 90 degree bend.
The bending radius should be at least twice the di-
ameter.
If longer ducts or more bends are used, the area
should be corrected by multiplying by a coefficient
from Table 1 below.
Number Duct length, m (ft)
of bends
1 (3.3)
5 (16.4)
1 1 1.04
2 1.39 1.41
3 – 1.70
Table 1.
Engine Instillation
2 (6.6) 3 (9.8) 4 (13.1)
1.09 1.13 1.20
1.43 1.45 1.49
1.72 1.74 1.78
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