Section 7 Ventilation

701. General of ventilation

1. The engine compartment is to be sufficiently ventilated with adequate natural ventilation, etc.

2. The dangerous ingress of water into the engine compartment through all inlets must be prevented.

3. The machinery spaces are to be provided with intake and discharge ducts of ventilating system and at least one intake duct are to be extended to the low location of proper space. The discharge duct may be connected to top of machinery space or to the natural or mechanical ventilator.

4. Where ventilation system is installed other than this regulation, the detail documents are to be sub- mitted to the Society before installation and it may be approved when it is considered equivalents.

702. Ventilation of petrol engine and/or petrol tank compartments

1. Natural ventilation systems

(1) Unless open to the atmosphere, each compartment contains a permanently installed petrol engine, a permanently installed petrol tank or a portable petrol tank in a craft is to have a natural ven- tilation system.

(2) Natural ventilation may be supply opening or supply duct or exhaust opening or exhaust duct

and each exhaust opening or compartment.

(3) Each supply opening or supply

exhaust duct is to originate in the lower one-third of the

duct and each exhaust opening or exhaust duct in a compart-

Ch 8 Machinery Installations Ch 8

ment is to be above the normal accumulation of bilge water.

(4) Compartment air intake and exhaust duct openings are to be separated by at least 600 mm, compartment dimensions permitting.

(5) Except as provided in (6), the combined area of supply openings or supply ducts, and the com- bined area of exhaust openings or exhaust ducts is to have a minimum internal cross-sectional area calculated as follows:

A GĖĖŊŊThŸFÃĤŊĦËĖF

where,

A : is the minimum combined internal cross-sectional area of the openings or ducts, (mmË) ;

V : is the net compartment volume equal to the total compartment volume minus the vol- ume of permanently installed components in it, (mĖ ).

(6) The minimum internal cross-sectional area of each supply opening or duct, and exhaust opening or duct is to exceed 3000 mmË.

(7) The minimum internal cross-sectional area of terminal fittings for flexible ventilation ducts in- stalled to meet the requirements of clause (5) is not to be less than 80 % of the required in- ternal cross-sectional area of the flexible ventilation duct.

(8) The exhaust of the natural ventilation system may be part of the powered ventilation system.

2. Power ventilation systems

(1) Unless open to the atmosphere, each compartment containing a permanently installed petrol en-

gine is to be provided with power ventilation system removing air from the compartment to the atmosphere outside the craft by an exhaust blower system.

(2) Each exhaust blower or combination of blowers are to be rated at an airflow capacity Ą Z not less than that given in Table 8.3. Blower rating is to be determined according to ISO 9097.

Table 8.3

(3) Each intake duct for an exhaust blower is to be in the lower one-third of the compartment and above the normal level of accumulated bilge water.

(4) More than one exhaust blower may be used in combination to meet the requirements of clause

(2).

(5) Each craft that has an exhaust blower is to have a label in accordance with 6.5 of ISO 11105

and to include an information in accordance with 7 of ISO 11105 in the owner's manual.

3. The ventilation duct sizes and airflow requirements are to be calculated based on compartment volumes.

4. Compartments containing petrol engines and/or petrol tanks are to be sealed from enclosed accom- modation spaces. Separating structures are regarded as being sealed if they fulfil the following re- quirements:

(1) the boundaries are welded, brazed, glued, laminated or the like;

(2) penetrations for cables, piping etc. are closed by fittings and/or sealants; and

(3) access openings, for example doors and hatches, are equipped with fittings and are secured.

5. No ventilation is required in petrol engine or petrol tank compartments which are open to the at- mosphere, that is; compartment or space having at least 0.34 mË of permanent open area directly

exposed to the atmosphere for each cubic meter of net compartment volume.

6. Neither supply nor exhaust ducts are to open into an accommodation space.

Ch 8 Machinery Installations Ch 8

7. Electrical components installed in petrol engine and petrol tank compartments and any connecting

compartments,

8846.

not open to the atmosphere, are to be ignition-protected in accordance with ISO

Ch 9 Electrical Equipment Ch 9