def stan 02 - 102 - air condition & ventilation

Requirements for Air Conditioning &Ventilation

Part 1HM Surface Ships and Royal Fleet

Auxiliaries

Ministry of Defence Defence Standard 02-102 (NES 102)

Issue 2 Publication Date 8 September 2000

Incorporating NES 102 Category 2

Issue 2 Publication Date March 2000

AMENDMENTS ISSUED SINCE PUBLICATION

AMD NO DATE OFISSUE

TEXT AFFECTED SIGNATURE &DATE

Revision Note

This Issue of this Standard has been prepared to incorporate changes to text and presentation.The technical content has been updated in line with current practice.

Historical Record

Def Stan 02-102 (Part 1)/Issue 1 1 April 2000NES 102 Issue 1 August 1983

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NAVAL ENGINEERING STANDARD 102

REQUIREMENTS FOR AIRCONDITIONING AND VENTILATION

PART 1 ISSUE 2 MARCH 2000

HM SURFACE SHIPS AND ROYAL FLEET AUXILIARIES

This Naval Engineering Standard

is authorized for use in MOD contracts

by the Defence Procurement Agency

and the Defence Logistics Organization

Published by:

Sea Technology Group,Defence Procurement Agency,STGSA,Ash 0, #95,MOD Abbey Wood,Bristol BS34 8JH

NES 102 Part 1Issue 2March 2000

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NES 102 Part 1Issue 2

March 2000

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SCOPE

1. This Naval Engineering Standard (NES) is applicable to all HM Surface Ships and Royal FleetAuxiliaries (RFA). It defines the requirements for providing ventilation, airconditioning andequipment cooling in surface ships, the standards to which the various systems associatedwith these functions are to be designed, manufactured and installed.

2. The requirements for airconditioning, ventilating, purging and air purification inHM Submarines are covered by NES 102 Part 2.


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March 2000

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FOREWORDSponsorship

1. This Naval Engineering Standard (NES) is sponsored by the Defence Logistics Organisation,Ministry of Defence (MOD).

2. The complete NES 102 comprises:

Requirements for Air-Conditioning and Ventilation

Part 1: HM Surface Ships and Royal Fleet Auxiliaries

Part 2: HM Submarines

3. Any user of this NES either within MOD or in industry may propose an amendment to it.Proposals for amendments that are not directly applicable to a particular contract are to bemade to the publishing authority identified on Page (i), and those directly applicable to aparticular contract are to be dealt with using contract procedures.

4. If it is found to be unsuitable for any particular requirement MOD is to be informed in writingof the circumstances.

5. No alteration is to be made to this NES except by the issue of an authorized amendment.

6. Unless otherwise stated, reference in this NES to approval, approved, authorized and similarterms, means by the MOD in writing.

7. Any significant amendments that may be made to this NES at a later date will be indicatedby a vertical sideline. Deletions will be indicated by 000 appearing at the end of the lineinterval.

8. This NES has been reissued because of technical update

Conditions of ReleaseGeneral

9. This Naval Engineering Standard (NES) has been devised solely for the use of the MOD, andits contractors in the execution of contracts for the MOD. To the extent permitted by law, theMOD hereby excludes all liability whatsoever and howsoever arising (including but withoutlimitation, liability resulting from negligence) for any loss or damage however caused whenthe NES is used for any other purpose.

10. This document is Crown Copyright and the information herein may be subject to Crown orthird party rights. It is not to be released, reproduced or published without written permissionof the MOD

11. The Crown reserves the right to amend or modify the contents of this NES without consultingor informing any holder.

MOD Tender or Contract Process12. This NES is the property of the Crown. Unless otherwise authorized in writing by the MOD

must be returned on completion of the contract, or submission of the tender, in connectionwith which it is issued.

13. When this NES is used in connection with a MOD tender or contract, the user is to ensure thathe is in possession of the appropriate version of each document, including related documents,relevant to each particular tender or contract. Enquiries in this connection may be made tothe authority named in the tender or contract.

14. When NES are incorporated into MOD contracts, users are responsible for their correctapplication and for complying with contractual and other statutory requirements.Compliance with an NES does not of itself confer immunity from legal obligations.


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Categories of NES15. The Category of this NES has been determined using the following criteria:

a. Category 1. If not applied may have a Critical affect on the following:

Safety of the vessel, its complement or third parties.

Operational performance of the vessel, its systems or equipment.

b. Category 2. If not applied may have a Significant affect on the following:

Safety of the vessel, its complement or third parties.

Operational performance of the vessel, its systems or equipment.

Through life costs and support.

c. Category 3. If not applied may have a Minor affect on the following:

MOD best practice and fleet commonality.

Corporate experience and knowledge.

Current support practice.

Related Documents16. In the tender and procurement processes the related documents listed in each section and

Annex A can be obtained as follows:

a. British Standards British Standards Institution,389 Chiswick High Road,London, W4 4AL

b. Defence Standards Directorate of Standardization, Stan 1, Kentigern House, 65 Brown Street, Glasgow, G2 8EX.

c. Naval Engineering Standards CSE3a, CSE Llangennech, Llanelli, Dyfed,SA14 8YP.

d. Other documents Tender or Contract Sponsor to advise.

17. All applications to the MOD for related documents are to quote the relevant MOD Invitationto Tender or Contract number and date, together with the sponsoring Directorate and theTender or Contract Sponsor.

18. Prime Contractors are responsible for supplying their subcontractors with relevantdocumentation, including specifications, standards and drawings.

Health and SafetyWarning

19. This NES may call for the use of processes, substances and/or procedures that are injuriousto health if adequate precautions are not taken. It refers only to technical suitability and inno way absolves either the supplier or the user from statutory obligations relating to healthand safety at any stage of manufacture or use. Where attention is drawn to hazards, thosequoted may not necessarily be exhaustive.

20. This NES has been written and is to be used taking into account the policy stipulated in JSP430: MOD Ship Safety Management System Handbook.

Additional Information21. (There is no relevant information included.)


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CONTENTSPage No

TITLE PAGE (i). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SCOPE (iii). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FOREWORD (v). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sponsorship (v). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conditions of Release (v). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Related Documents (vi). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Health and Safety (vi). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONTENTS (vii). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 1. GENERAL INFORMATION 1.1. . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Climatic Conditions 1.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Design Conditions 1.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Ship Subdivision 1.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Operational States 1.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 2. DESIGN REQUIREMENTS/CRITERIA 2.1. . . . . . . . . . . . . . . 2.1 General Requirements 2.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Environment Conditions 2.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2.1 Basic Air-Conditioning System 2.2. . . . . . . . . . . . . . . . . . . . . . . . Figure 2.2 Typical Air-Conditioning Cycle 2.3. . . . . . . . . . . . . . . . . . . . . . . 2.3 Air-conditioning and Ventilation Systems 2.4. . . . . . . . . . . . . . . 2.4 Machinery Spaces 2.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 Smoke Clearance 2.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 Chilled Water Systems 2.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 Local Exhaust Ventilation Systems 2.7. . . . . . . . . . . . . . . . . . . . .

SECTION 3. DESIGN PROCEDURE 3.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Concept Studies 3.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Feasibility 3.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Design Leading to Contract Definition 3.4. . . . . . . . . . . . . . . . . 3.4 Detailed Design 3.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 4. DESIGN DATA 4.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 Environmental Design Conditions 4.1. . . . . . . . . . . . . . . . . . . . . 4.2 Cooling and Heating Assumptions 4.2. . . . . . . . . . . . . . . . . . . . . 4.3 Total Heat Transfer Coefficient k 4.3. . . . . . . . . . . . . . . . . . . . 4.4 Relative Humidity 4.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Air Distribution Systems 4.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.1 Design Margin 4.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.2 Air Velocities 4.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.3 Fresh/Filtered Air Requirements 4.5. . . . . . . . . . . . . . . . . . . . . . 4.5.4 Standard NBC Filters 4.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


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Page No4.6 Pressurization 4.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.1 Citadel and Zones 4.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.2 Machinery Spaces 4.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 Heating Systems 4.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 Chilled Water Systems 4.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8.1 Design Margins 4.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 Chilled Water Temperatures 4.7. . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Velocities and Pipe Size 4.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 5. AIR DISTRIBUTION SYSTEMS 5.1. . . . . . . . . . . . . . . . . . . . . . 5.1 Design Objective 5.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 General Requirements 5.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 Air-conditioning Arrangements 5.2. . . . . . . . . . . . . . . . . . . . . . . 5.4 Central ATU 5.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Compartment ATU 5.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 ATU Controls 5.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7 Special Requirements 5.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7.1 Operational Spaces 5.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7.2 Accommodation and Recreation Spaces 5.4. . . . . . . . . . . . . . . . 5.8 Medical Spaces 5.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8.1 Sick Bays 5.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9 Configuration No 1 (Full fresh air cooling) 5.6. . . . . . . . . . . . . . 5.10 Configuration No 2 (Semi-recirculation) 5.6. . . . . . . . . . . . . . . . 5.10.1 Dental Surgery 5.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11 Bathrooms and WC 5.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11.1 General Requirements 5.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11.2 WC and Urinals 5.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11.3 Bathrooms 5.9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.12 Galleys and Associated Spaces 5.10. . . . . . . . . . . . . . . . . . . . . . . . 5.12.1 Galley, Servery and Scullery 5.10. . . . . . . . . . . . . . . . . . . . . . . . . . 5.12.2 Pantries and Pantry/Serveries 5.11. . . . . . . . . . . . . . . . . . . . . . . . 5.12.3 Miscellaneous 5.11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.13 Laundries and Associated Spaces 5.12. . . . . . . . . . . . . . . . . . . . . . 5.14 Drying Rooms 5.12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.15 Workshops 5.13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.16 Sewage Treatment Spaces 5.14. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.17 Storerooms 5.14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.18 Conversion Machinery Rooms 5.14. . . . . . . . . . . . . . . . . . . . . . . . 5.19 Magazines 5.15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.20 Compartments Containing Dangerous or Noxious Gases 5.17. . 5.20.1 General Requirements 5.17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.21 Refrigeration Machinery Compartments, Refrigeration

Machinery and Bottle Stowages for Heavier than Air Gases 5.185.22 Battery Charging Rooms and Spaces Containing

Battery Charging Facilities 5.18. . . . . . . . . . . . . . . . . . . . . . . . . . . 5.23 Paint Rooms, Paint Stores and Flammable Stores 5.19. . . . . . . .


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Page No5.24 Hydrogen and Acetylene Storage Compartments 5.19. . . . . . . . . 5.25 Compartments Containing Petroleum, Oils, Lubricants, etc. 5.205.26 HP Air Compressors 5.21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.27 Incinerator Compartments 5.21. . . . . . . . . . . . . . . . . . . . . . . . . . . 5.28 Hangars 5.21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.29 Vehicle Decks 5.22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.30 Electrical Switchboard Rooms 5.23. . . . . . . . . . . . . . . . . . . . . . . . 5.31 Emergency Generator Compartment 5.23. . . . . . . . . . . . . . . . . . 5.32 Steering Gear (Secondary Steering Position) 5.23. . . . . . . . . . . . 5.33 Dry Provision Room 5.23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.34 Air Balance Diagrams 5.23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 6. COOLING SYSTEMS 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 General 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Statement of Style 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Design Principles 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 6.1 Combined Essential and Non EssentialServices

Chilled Water System 6.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 6.2 Discrete Essential Services Chilled Water System 6.4. . . . . . . . 6.4 System Arrangement and Components 6.5. . . . . . . . . . . . . . . . . 6.5 CW/Air Heat Exchangers (Coolers) 6.6. . . . . . . . . . . . . . . . . . . . 6.6 Materials 6.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.7 Cleanliness 6.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.8 Water Quality 6.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.9 Compartment Cooling 6.9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.10 Air Treatment Units 6.9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.11 CW Unit Coolers 6.9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.12 Free Standing Air-conditioning Units 6.10. . . . . . . . . . . . . . . . . . 6.13 Equipment Cooling 6.10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.14 Demarcation 6.11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.15 Dehumidifiers and Condensation Control 6.11. . . . . . . . . . . . . . . 6.16 Insulation 6.11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.17 System Reliability 6.11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 7. HEATING SYSTEMS 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1 General Requirements 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Air-conditioned Compartments 7.1. . . . . . . . . . . . . . . . . . . . . . . 7.3 Hazardous Compartments Within the NBC Citadel 7.2. . . . . . 7.4 Fresh Air 7.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 Compartments Outside the NBC Citadel

(Ex Machinery Spaces) 7.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6 Classification of Heaters 7.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.1 Supplementary/Boost Heaters 7.3. . . . . . . . . . . . . . . . . . . . . . . . . 7.6.2 Reheaters 7.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7 Heater Controls 7.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.1 Positioning of Sensors 7.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


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Page No

7.8 Electric Heater Controls 7.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9 Hot Water Heater Controls 7.4. . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10 Trunk Mounted Heaters 7.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10.1 Electric Heaters 7.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10.2 Hot Water Heaters 7.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11 Space Heating 7.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.1 Types of Space Heaters 7.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.12 Hot Water Systems 7.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.13 Heater Markings 7.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.14 Humidifiers 7.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 8. MACHINERY SPACES 8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1 System Design 8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1.1 Cruise State/Open Ship Condition 8.1. . . . . . . . . . . . . . . . . . . . . 8.1.2 Action State/Closed Down Condition 8.1. . . . . . . . . . . . . . . . . . . 8.2 Cooling 8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3 Pressurization 8.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4 Air Systems 8.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5 General 8.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.6 Heating 8.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7 Machinery Space Ventilation Trials 8.4. . . . . . . . . . . . . . . . . . . .

SECTION 9. NBCD & FIRE FIGHTING ARRANGEMENTS 9.1. . . . . . . . . 9.1 NBCD Subdivision (See NES 118) 9.1. . . . . . . . . . . . . . . . . . . . . 9.2 Fire Fighting Subdivision (See NES 119) 9.1. . . . . . . . . . . . . . . . 9.3 Citadel Pressurization 9.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4 Intake of Ambient Air 9.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4.1 Calculated Uncontrolled Leakages 9.2. . . . . . . . . . . . . . . . . . . . . 9.4.2 Known Controlled Leakages 9.3. . . . . . . . . . . . . . . . . . . . . . . . . . 9.4.3 Control Of CO2 9.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5 Air Filtration Units and NBC Filters 9.3. . . . . . . . . . . . . . . . . . . 9.5.1 Centralised AFU 9.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5.2 Specialised AFU 9.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.6 Purging 9.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.7 Air Locks (Citadel Exits) 9.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.8 Cleansing Station (Contamination Control Area) 9.6. . . . . . . . 9.9 Fire Fighting and Fire Precautions 9.6. . . . . . . . . . . . . . . . . . . . 9.10 Smoke Clearance/Containment - Policy (Surface Ships) 9.7. . . 9.11 Crash Stopping of Fans 9.9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.12 High Risk Areas 9.10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.12.1 Galleys (Also See Section 5) 9.10. . . . . . . . . . . . . . . . . . . . . . . . . . . 9.13 Highly Flammable Stores and Explosive Gases 9.11. . . . . . . . . .


March 2000

(xi)

Page No9.14 Fire Flaps 9.11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 9.1 Typical Fire Flap 9.12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 9.2 Typical Flameproof Gauze 9.13. . . . . . . . . . . . . . . . . . . . . . . . . . . 9.15 NBCD Ventilation Board 9.14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.16 Fire Precautions in Royal Fleet Auxiliary Vessels 9.14. . . . . . . . .

SECTION 10. FANS 10.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1 Fan Selection 10.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 Materials 10.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3 Construction 10.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 10.1 Application of Constant Orifice Line to

Design Margins 10.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4 Motors 10.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5 Availability, Reliability and Maintainability (ARM) 10.3. . . . . . 10.6 Noise 10.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.7 Shock 10.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.8 Vibration (Self Generated) 10.3. . . . . . . . . . . . . . . . . . . . . . . . . . . 10.9 Vibration (Externally Generated) 10.3. . . . . . . . . . . . . . . . . . . . . . 10.10 Fan Testing 10.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.11 Mounting and Siting of Fans 10.4. . . . . . . . . . . . . . . . . . . . . . . . . . 10.12 Special Fans 10.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.13 Fan Markings 10.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 11. TRUNKING AND FITTING 11.1. . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 General 11.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Non-Watertight, Non-Gastight Trunks 11.1. . . . . . . . . . . . . . . . . 11.3 Textile Ventilation Trunking 11.2. . . . . . . . . . . . . . . . . . . . . . . . . . 11.3.1 Advantages 11.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3.2 Disadvantages 11.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4 Gastight and Structural Trunks and Trunks

Subjected to Rough Usage or High Fire Risk Including Smoke Removal Systems 11.4. . . . . . . . . . . . . . . . . . . .

11.5 Watertight Trunks 11.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.5.1 Trunk Installation. 11.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.6 Vulnerability 11.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 11.1 Typical Hanger Supports 11.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.7 Trunking - Associated Fittings 11.8. . . . . . . . . . . . . . . . . . . . . . . . 11.8 Weather Terminals 11.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.9 Supply Outlets 11.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.10 Exhaust/Recirculation Intakes 11.9. . . . . . . . . . . . . . . . . . . . . . . . 11.11 Miscellaneous Fittings 11.9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.12 Insulation 11.10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 11.2 Typical Hose Conection for Ventilation Trunks 11.11. . . . . . . . . .

SECTION 12. FILTRATION 12.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1 General 12.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2 Dust Filters 12.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


(xii)

Page NoFigure 12.1 Typical Dust Filter Mounted in a Trunk 12.3. . . . . . . . . . . . . . . . Figure 12.2 Typical Dust Filter for Openings in Exhaust

and Recirculation Trunks 12.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3 Odour Filters 12.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.4 Tobacco Smoke Filters 12.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.5 Grease Filters 12.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 12.3 Typical Tobacco Smoke Filter 12.6. . . . . . . . . . . . . . . . . . . . . . . . . 12.6 Fresh Water Filters 12.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.7 Standard NBC Filters 12.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 13. VENTILATION NOISE 13.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.1 General 13.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2 Siting and Mounting of Fans 13.1. . . . . . . . . . . . . . . . . . . . . . . . . . 13.3 Trunking and Fittings 13.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.4 System Sound Analysis 13.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.5 Tests and Trials 13.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 14. DESIGN FOR MAINTENANCE ANDSHIP HUSBANDRY 14.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14.1 General 14.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2 Fittings 14.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3 Drainage 14.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.4 Filters 14.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.5 Water Systems 14.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 15. INSPECTIONS, TESTS AND TRIALS 15.1. . . . . . . . . . . . . . . . . 15.1 General Comments 15.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.2 Factory Testing 15.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.2.1 Type Tests 15.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.3 Production Tests 15.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.4 Progress Inspections 15.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.5 NBC Filtration, Inspection and Testing 15.3. . . . . . . . . . . . . . . . . 15.6 Final Inspection 15.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.7 Testing and Balancing 15.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.7.1 Air Systems 15.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.8 Air Test Reports 15.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.9 Water Systems 15.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.10 Zonal Pressures Tests 15.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.11 Habitability Trials 15.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.12 Performance Trials 15.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.13 Airborne Noise Trials/Surveys 15.9. . . . . . . . . . . . . . . . . . . . . . . . 15.14 Instruments 15.10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ANNEX A. RELATED DOCUMENTS A.1. . . . . . . . . . . . . . . . . . . . . . . . . . .

ANNEX B. ABBREVIATIONS AND DEFINITIONS B.1. . . . . . . . . . . . . . .

ALPHABETICAL INDEX INDEX 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


March 2000

1.1

1. GENERAL INFORMATIONRelated Documents: NES 809 Part 1; see also Annex A.

1.1 Climatic Conditions

a. For design purposes hot weather and cold weather climates throughout theworld are each divided into the following conditions, viz:

(1) Hot Weather

(a) Tropical;

(b) Temperate Summer.

(2) Cold Weather

(a) Temperate Winter;

(b) Subarctic;

(c) Arctic.

1.2 Design Conditions

a. The limiting climatic conditions to be applied to any ship design will be specifiedin the Staff Requirements (Sea) (SR(S)) for that particular class of vessel andthus, in consequence of this NES, the internal ship conditions will also bedefined.

b. The SR(S) will also indicate where the actual design may, if at all, deviate fromthe standards and policies herein and, where appropriate, it will specify themodified standards that are to be achieved.

c. Unless specifically modified by the SR(S) it is essential that all the marginsstated in this NES are applied fully throughout the design. Initial allowancesconsumed by growth during the design stages need to be compensated for, toensure sufficient margins are present in the final design to allow for through lifegrowth and degradation of the various systems. The chilled water margins arealso required as airconditioning machinery cannot be run under overloadconditions. If an attempt is made to do so the plant may trip out, resulting in asignificant reduction in the ships operational efficiency. Allowances for erosionof growth margins will be discussed and identified at the outset of the designcalculations.

d. HM Surface ships that are to be commercially registered, e.g. Royal FleetAuxiliaries (RFA) are, where possible, to comply with Department of theEnvironment, Transport and the Regions (DETR) regulations that governfirefighting and safety aspects. Where DETR and MOD standards are atvariance and both sets of regulations can be accommodated then the morestringent are to be applied. As it is imperative that Nuclear Biological andChemical Defence (NBCD) integrity and the operational efficiency are notjeopardised in any circumstances any DETR rules or regulations which placethe vessel at risk shall not be applied and the relevant exception to or exemptionfrom these rules should be sought from the regulatory body and entered in thecommercial registration documents. Full compliance with DETR regulationswill be impossible as they have no category suitable for HM Surface Ships andwould normally register the vessel in the closest appropriate commercialclassification. In these circumstances discussions should take place at theoutset of the design where differences or conflicts will be clearly identified andreconciled by all concerned parties.


1.2

e. In all surface ship designs, unless stated otherwise in the SR(S), it is importantto achieve a reduced Radar Cross Section (RCS). The recommendations ofNES 809 Part 1 are to be addressed in the design of all external features, and inparticular the creation of orthogonal dihedrals and trihedrals with cositedfeatures is to be avoided.

1.3 Ship Subdivision

a. For each new class of surface ship the MOD will produce a ship subdivisionpolicy paper in the early stages of, or prior to, Feasibility Design that willcomprehensively state the rules governing the subdivision of that particularclass of vessel.

b. Surface ships can be divided as:

(1) Watertight decks and bulkheads;

(2) NBCD citadels and subcitadels;

(3) Autonomous fire/smoke zones and ventilation subzones within theautonomous zones.

c. The design of the ventilation and airconditioning arrangements are to becompatible with each of these subdivisions and the ducted systems are to beautonomous within individual fire zones. In the action state when allsubdivision boundaries are secured the free flow of recirculated air fromcompartment back to fan is not to be obstructed.

1.4 Operational States

a. Two operational states have to be catered for, viz:

(1) Cruise state or open ship condition;

(2) Action state or closed down condition.

b. Within the NBCD citadel, the change from cruise to action state is to be effectedby implementing air lock, cleansing station and zonal disciplines andredirecting all incoming fresh air through NBCD filters. Ventilation andairconditioning systems are not to be reconfigured to enable this to beachieved.

c. For those compartments outside the NBCD citadel and classed as contaminatedif used, every effort is to be made for these spaces to be supplied with air fromthe citadel with natural or fan exhaust to atmosphere. Only when these spacesentail excessive amounts of conditioned air should mechanical fan supply andexhaust systems be considered. In the machinery spaces, it is to be achieved byreconfiguring the ventilation systems into recirculation systems, closingexternal openings, supplying chilled water to machinery space coolers andinitiating dedicated filtration units.

d. Once closed down it is to be possible to maintain that condition indefinitelywithout discomfort to personnel or loss of operational efficiency, unless theSR(S) for the vessel stipulates a specific time scale.


March 2000

2.1

2. DESIGN REQUIREMENTS/CRITERIARelated Documents: Health and Safety at Work Act, COSHH Regulations; see also

Annex A.

2.1 General Requirements

a. This section deals with the requirements governing the overall design ofventilation and airconditioning arrangements that are to be fitted in RoyalNavy (RN) vessels. It defines the current policy that is to be applied anddescribes the style of various associated systems. It is the Designersresponsibility to incorporate these requirements.

b. Airconditioning, that is the control of temperature, humidity, air purity and airmovement within a space or group of spaces, is a prime requirement in all RNvessels. It is an essential element in ensuring that the ships staff continue tooperate at high levels of effectiveness and efficiency for long periods and theenvironment for weapons and other essential equipments is, and alwaysremains, satisfactory for reliable operation. This environmental control has tobe achieved throughout the full spectrum of ambient conditions for which theship is to be designed.

c. All compartments within a ship are to be classified by the designer as eitheressential or nonessential to the operational efficiency of the vessel and theseclassifications made known in the airconditioning design.

d. For essential compartments the airconditioning is to be based upon the GroupSystem where a mixture of fresh and recirculated air is delivered to an AirTreatment Unit (ATU) where it is filtered, cooled or heated, and distributed to aselected group of essential compartments (A group can be one or severalcompartments). In certain circumstances the cooled air may need to bereheated locally before being delivered to particular spaces to obtain thenecessary humidity control, but the use of this technique is to be kept to aminimum (See Figures 2.1 and 2.2).

e. For nonessential compartments the airconditioning is to be based either uponthe Group System as described above, except that the relevant ATU is to onlysupply nonessential spaces, or, if more appropriate, on the use of Unit Coolers.

2.2 Environment Conditions

a. The design of the airconditioning systems is to cater for the extreme ambienttemperatures stated in the SR(S) and the corresponding internal temperaturesgiven in Section 4. The final design of the installed systems is to includesufficient flexibility and controllability to allow comfortable internalenvironments to be selected and maintained throughout the full range ofconditions bounded by these extremes. This flexibility is especially importantin spaces where the internal conditions can vary significantly and speedily dueto movement of personnel or change of equipment status and should beachieved by the use of sensors situated in appropriate locations.


2.2

RETURN

A

SUPPLY TRUNK

THERMOSTAT

BOUNDARY GAINS - (SH)EQUIPMENT (SH+LH, IF ANYPERSONNEL (SH+LH)

HOT MACHINERY SPACE ETC.

C

RECIRCULATED AIR ROUTE(MAY BE TRUNKED)

EVAPORATOR

CONDENSER

COMPRESSOR

C.W. PUMP

REFRIGERANT CIRCUIT

HEAT EXCHANGER

CHILLED WATER PLANT

FRESH FILTEREDAIR DIRECT FROMAFU SH+LH

ELECTRIC PRE-HEATERCHILLED WATER SYSTEM

ELECTRICRE-HEATER

CONNECTION BOX

AIR TREATMENT UNIT

MOISTURE ELIMINATOR

FILTER

B

BYPASS

FAN

A1

SURPLUS AIR DISCHARGEDOVERBOARD VIA HAZARDOUSCOMPARTMENT EXHAUST

SOLAR RADIATION

FLOW

NOTE A, A1, B, C and D REFER TOPOINTS SHOWN IN FIGURE 2.2NOTESH - Sensible HeatLH - Latent HeatAFU - Air Filtration Unit

CONDENSER COOLING WATER

D

Figure 2.1 Basic Air-Conditioning System


March 2000

2.3

C

5

10

15

20

25

040302010

RELATIVE HUMIDITY

50

70

60

90

100%

90%

DRY BULB TEMPERATURE deg C

MO

ISTURE CONTENT g/Kg

12.5

10

15

17.5

22.5

25

27.5

20

D

A

B

A1

Air-ConditioningCYCLE

80

NOTEFor information onA, A1, B, C and DSee Figure 2.1

Figure 2.2 Typical Air-Conditioning Cycle


2.4

2.3 Air-conditioning and Ventilation Systems

a. In all ships, where required, the complete airconditioning and ventilationdesign for compartments and spaces necessary for the functionality of thevessel in a closed down ship, is to be based upon the Total Atmospheric ControlSystem (TACS) concept which has been developed to achieve the minimumpracticable changeover time from open ship to closed ship condition and toenable continuous operations to be conducted in a Nuclear, Bacteriological andChemical Warfare (NBCW) threat situation. This concept requires all fresh airentering the NBCD citadel to be directed through NBC filtration units when inthe closed down condition but in the open ship condition these filters are to bebypassed. Compartments not necessary for the functionality of the vesselduring NBC transits should not ideally be located within the citadel but due tothe logistics of the ship they may well be and in these instances would beairconditioned or ventilated as required. In such cases theairconditioning/ventilation is normally to be by independent systems takingtheir required fresh air quantities from weather (not via Air Filtration Units AFU) and they would be secured in a closed down situation, however inisolated cases these spaces can be served by an adjacent TACS airconditioningsystem.

b. All compartments and spaces within the citadel are to be airconditioned orventilated as above with the exception of those compartments classed ashazardous, i.e. compartments within the citadel which contain materials thatmay generate dangerous or toxic fumes and gases and those where such fumesand gases are produced by processes and functions carried out in thecompartment. These spaces are to be airconditioned/ventilated to conditionsspecified in Section 5 Clause 5.20.

c. Special attention is to be paid to those compartments within the citadel that area source of unpleasant smells or noxious gases, e.g. bathrooms, WC, laundries,galleys, etc. In these types of compartment sufficient air is to be circulated toensure that odours are removed via a recirculation system employing odourfilters. For specific requirements for these compartments See Section 5.

d. The design of the air systems is to take account of and be compatible with theshipsubdivision policy for each particular ship design. The air systems are tobe completely autonomous within the fire/smoke zones, and under nocircumstances is ducting to breach zone boundaries. It is essential that airbalance diagrams for each fire zone are prepared and maintained throughoutthe design to ensure that differential pressures across zonal boundaries aremaintained within the limits specified in Section 9.


March 2000

2.5

e. In both the closed down and open ship conditions the fresh air intake into thecitadel is to be via the AFU fans (See Figure 2.1). The fresh air quantity is to besufficient to compensate for known controlled losses and calculateduncontrolled leakages, whilst maintaining an acceptable citadel over pressureand providing oxygen to revitalise compartment air by ensuring that CO2content levels are kept below the maximum permissible levels. The fresh airrequired for oxygen replenishment is to be trunked direct to individual ATUwhere it is treated and distributed as necessary. The remaining fresh air is to beused to provide an over pressure in essential compartments (See Section 9) or isto be trunked from the AFU fan directly to or in the vicinity of anycompartment, Air Lock or Cleansing Station deemed necessary for maintainingthe integrity of the citadel.

2.4 Machinery Spaces

a. Machinery spaces are to be considered as outside of the NBCD citadel and in theopen condition are to be ventilated by mechanical supply and mechanicalexhaust systems. The flow of air is to be such that in specified summerconditions the compartment temperature will be maintained within statedlimits when all normally running equipments are operating. In cold weatherconditions the air flow is to be capable of being significantly reduced andsufficient electric heating provided to maintain temperatures which facilitatethe ease of starting up of machinery (normally 10C) in the dead shipcondition.

b. The system design is to provide, where required, for the reconfiguration of theventilation systems so that, in the closed down condition it will be possible torecirculate the compartment air through chilled water coolers and isolate themachinery spaces from the external ambient air. In this state a positivepressure (normally 3 millibars above ambient air pressure) is to be created andmaintained in the machinery spaces by introducing a quantity of fresh airthrough dedicated NBC filtration units. These filtration units are to benonoperational in the open ship condition and the quantity of fresh airrequired is to be calculated by the summation of any known controlled lossesand the calculated uncontrolled leakages based on a loss of 0.5air changes perhour on the gross volume of the machinery spaces inclusive of casings if open tothe machinery space.

c. The chilled water coolers in machinery spaces are to be operational in theclosed down state and capable of being supplied from a standby nonessentialchilled water plant. Sufficient heat is to be extracted to allow the ship to be fullyoperational for the total closed down period and at the extreme ambienttemperatures specified in the SR(S), without these spaces becomingcontaminated. Machinery space closed down cooling requirements are to betaken into account when allocating the number and capacity of theairconditioning chilled water refrigeration plants.

2.5 Smoke Clearance

a. Where a ship design includes damage fire and smoke zones, a dedicated trunkedsmoke clearance system is to be provided in each zone. These systems are to bearranged such that, within each zone, individual decks may be cleared of smokeand allow sufficient replacement air, without other unaffected decks beingcontaminated.

b. Dedicated smoke clearance systems are not required in machinery spaces whichcontain exhaust fans as these fans will be utilised for smoke clearance.


2.6

c. To prevent the migration of smoke into compartments essential to theoperational efficiency of the vessel in a fire situation, such compartments are tobe capable of being maintained at a positive pressure relative to thesurrounding passageways and lobbies.

2.6 Chilled Water Systems

a. Chilled Water (CW) systems are to provide the means for transferring heat fromthe heat exchangers, situated throughout the vessel, to Chilled Water Plants(CWP) and hence overboard via condenser cooling water.

b. Two categories of CW systems are to be included in any ship design, namely:

(1) Essential systems supplying essential heat exchangers that cool essentialcompartments and equipments. These systems are to be constrainedwithin NBCD/smoke zones and several of this type will be included ineach ship design;

(2) Nonessential systems supplying nonessential ATU and unit coolers thatcool nonessential spaces. This will be a ship wide system and each shipwill only contain one of this type.

c. Connections are to be provided between the nonessential system and eachessential system to enable the essential heat exchangers to be continuouslysupplied, when necessary, at the expense of the nonessential.

d. Adequate margins are to be applied to allow for through life growth and systemdegradation when selecting CWP and calculating pipe sizes.

e. The nonessential system is to be provided with a standby CWP so that allsystems will be able to operate continuously during periods of routinemaintenance or single plant breakdown. The standby CWP is not to beconsidered as a growth margin.

f. In any ship design the preferred arrangement is for all essential systems to beserved by identical CWP, a single plant supplying each system, and for all CWPserving the nonessential system to be identical.

g. The nonessential CWP are to be capable of cooling the machinery spaces in theclosed down condition.

h. Rapid refill arrangements as well as normal toppingup facilities are to beprovided.

i. The design of the system and its associated equipment is to ensure that theRelative Humidity (RH) levels in individual compartments are maintainedbetween specific upper and lower limits but in exceptional circumstances, indifficult spaces, the use of approved humidifiers and dehumidifiers isacceptable.

j. In particular compartments where heavy condensation is liable to occur specialattention is to be given during the design stage to removing moisture from thecirculating air and to the use of thermal insulation to eliminate potentialproblems.


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2.7

2.7 Local Exhaust Ventilation Systems

a. Those systems defined under the Health and Safety at Work Act (HSWA),Control of Substances Hazardous to Health (COSHH) Regulations 1992 asLocal Exhaust Ventilation (LEV) Systems are to be provided, these are toinclude fixed monitoring instrumentation to allow for through life ventilationsystem flow monitoring.

b. Each designated LEV system is to have:

(1) The test point(s) marked;

(2) The required test date annotated on a plate and fixed adjacent to the testpoint;

(3) The test date plate to be permanently fixed to the trunking.


2.8


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3.1

3. DESIGN PROCEDURERelated Documents: BS 1553 and NES 707 Parts 1 & 2; see also Annex A.a. The design of the airconditioning and ventilation systems is to follow and

reflect the total ship design. When considering the various types of studiesundertaken it is to be understood that a ship design is a dynamic entity wheredecisions taken in one area, will often have repercussions in many other areasand airconditioning and ventilation estimates, calculations, drawings, etc.,will need to be continually reassessed and updated.

b. Within the field of airconditioning and ventilation the total design process canbe divided as follows:

(1) Concept studies;

(2) Feasibility studies;

(3) Design leading to Contract Definition;

(4) Detailed design.

3.1 Concept Studies

a. These are studies to formulate new design philosophy, policies and criteria andto assess the impact of any proposed changes in future ship design. They areusually undertaken by the MOD with assistance from selected contractors, andare not necessarily associated with a particular ship design.

3.2 Feasibility

a. These are studies to combine the existing philosophy, policies and criteria with adeveloping ship design, for a specific role, and are normally carried out by ashipbuilder and his prime contractor, with assistance from MOD sponsors.

b. For feasibility studies to commence, the following information is required:

(1) Design conditions;

(2) Ship subdivision policy;

(3) Compartment details (size, manning, function, wild heat, etc.);

(4) Weapons fit and direct cooling loads.

c. This information is to be available from MOD sources when the SR(S) isapproved. When this is not the case the best possible estimates and assessmentsare to be made to allow the design of the airconditioning and ventilationsystems to be progressed as soon as possible and updated when absolute detailsare obtained by the shipbuilder.

d. During this stage of the design the following information is to be submitted tothe MOD for records and, where necessary, comments:

(1) Design philosophy table giving details of Heating Ventilation andAirConditioning (HVAC) requirements for all compartments on thevessel. This table should include the compartment name, location,specified summer and winter conditions to be maintained, exhaustrequirements, noise target and manning levels, equipment wild heatemissions and any additional remarks pertinent to the design of theHVAC system;


3.2

(2) Statements of Technical Requirements (STR) for fans, heaters, coolers,etc., and programmes for testing new equipments and fittings thatrequired approval to fit;

(3) Classification of compartments as essential, nonessential andhazardous, and identification of those outside citadel boundaries;

(4) Calculations of heat gains and losses for every compartment, workshopand store, etc.;

(5) Grouping of compartments to show the number of essential andnonessential heat exchangers/ATU, the number of hazardous systemsand the number of ventilation systems required in each NBCD/fire zone;

(6) Selection of type, size and numbers of CWP for essential andnonessential CW systems;

(7) Calculations of air quantities and CW flows required for all systems;

(8) Size, type and numbers of fans, air/water and water/water heatexchangers, heaters, humidifiers and other equipments;

(9) Fresh air requirements in individual zones, machinery spaces and thenumber of AFU required;

(10) Identification of compartments to be pressurized by a direct supply offresh air to prevent infiltration of smoke;

(11) Identification of ventilation and smoke clearance systems;

(12) Calculation of trunk and pipe sizes;

(13) Calculation of induct and breakout noise levels in mannedcompartments and assessment of all the acoustic insulationrequirements;

(14) Calculation of space relative humidities and identification ofhumidification requirements;

(15) Statement of electrical requirements, including crash stopping of fans;

(16) Table of weights.

e. During this design stage, to augment the calculation sheets and equipment listsindicated above, the following drawings are to be prepared, continuallyupdated as necessary and submitted to the MOD immediately prior to the handover of the vessel so that calculations and drawings reflect the completed HVACsystems.

(1) Scaled single line Air Systems General Arrangement drawings on deckplans showing:

(a) All air systems, i.e. essential, nonessential, hazardous, fresh,smoke clearance, natural and mechanical ventilation;


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3.3

(b) Position of ATU and other air/water and water/water heatexchangers;

(c) Position of AFU;

(d) Zonal boundaries and watertight subdivision;

(e) Siting of fans, heaters, filters, moisture eliminators, valves andother fittings;

(f) Type, size and number of terminals fitted in each space;

(g) Sizes of trunks;

(h) Extent of watertight and gastight trunking;

(i) Citadel boundary.

(2) Air balance diagrams for each NBCD/fire zone and machinery space todemonstrate that in closed down conditions:

(a) Recirculation routes from airconditioned compartments back tofan intakes are unobstructed by doors, hatches, fire curtains, etc.;

(b) Access to and from adjacent zones will not be hampered byunacceptable differential air pressures;

(c) Hot, oil contaminated air will not migrate from the machineryspaces into the citadel.

(3) Planimetric drawings of each essential and nonessential chilled watersystem indicating:

(a) All pipe runs, tee junctions, bends, etc.;

(b) All air/water and water/water heat exchangers and thecompartments/equipments supplied by each one;

(c) All control panels, filters, flow switches, air vents, sampling points,isolating valves and other fittings inserted in the pipelines;

(d) The CWP and pumps, with cross connections where applicable;

(e) Pipe lengths and diameters between junctions for both flow andreturn pipes;

(f) Flow of CW in m3/s through each pipe section.

(4) Scaled single line CW Systems General Arrangement drawing on deckplans showing:

(a) Pipe routes;

(b) Position of CWP and pumps;

(c) Zonal subdivision;

(d) Position and classification of each heat exchanger, i.e. essential,nonessential or stand by.


3.4

3.3 Design Leading to Contract Definition

a. During this stage the airconditioning and ventilation systems are to becontinually amended and updated to reflect changes made in the overall shipdesign. In addition the many and varied estimates, used during the feasibilitystage, are to be progressively refined and confirmed with the calculations,equipment selections, drawings, etc., produced during that stage, beingreassessed as necessary.

b. By the end of this stage the following is to be complete:

(1) All basic design data confirmed;

(2) Classification and grouping of compartments agreed;

(3) All calculations of air flows, CW flows, trunk and pipe sizes finalized;

(4) Selection of equipments and materials approved and where appropriateconfiguration definition packages prepared;

(5) Selection of fittings agreed and where appropriate new types of fittingstested and approved for use;

(6) Upgrading of Air Systems General Arrangement drawings to doubleline convention;

(7) Upgrading of Chilled Water Systems General Arrangement drawings toshow supply and return leads and siting of all fittings included in thepipework;

(8) CW planimetric, air balance diagrams, upgraded general arrangements,configuration definition packages, etc., are all to be brought toModification State Zero, i.e. the stage at which the MOD will become theDesign Authority (DA) for support;

(9) Electrical requirements finalized;

(10) Statement of Requirements for Total Ship System and Design Critiqueprepared and agreed.

3.4 Detailed Design

a. Large scale layout drawings of compartments and spaces are to be producedwhich accurately show the final positions and sizes of all CW and condensatepipes, airconditioning and ventilation trunking, equipments and fittings,electrical leads and controls, etc., that are associated with the airconditioningand ventilation of the vessel. These drawings are also to show the clear accessareas that are required to enable items, such as filters and fan motors, to bewithdrawn for servicing.

b. Drawings are to be prepared to demonstrate the method of handling heavyequipments, such as fans, heat exchangers and AFU in congested areas toenable repair or replacement of these equipments to be carried out at sea.

c. All drawings, equipment lists, data sheets, etc., prepared during the previousstages are to be amended, as necessary, to reflect the final ship fit.

d. Throughout all stages of the design the symbols and line conventions used whenproducing the required drawings are to be in accordance with NES 707 Parts 1& 2 and BS 1553 Parts 1 & 3.


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4.1

4. DESIGN DATARelated Documents: ISO 7547 and NES 111; see also Annex A.

a. The calculation of heating and cooling loads and the sizing of pipes and ductingcan be carried out by manual methods or by computer programs. In either casethe calculations are to be based upon the design data given in this section andproven established processes such as Building Services Research IndustrialAssociation (BSRIA), Engineering System Design Methods (ESDM), CivilInstitute Building Services Engineering (CIBSE) and International StandardsOrganisation (ISO) 7547, etc.

4.1 Environmental Design Conditions

a. External Temperatures (Hot Climates)

Climate Dry Bulb(DB)CWet Bulb(WB)C

SurfaceSea Temperature C

Tropics 35 30 33

Temperate Summer 30 24 29

b. External Temperatures (Cold Climates)

Climate Dry Bulb(DB)CWet Bulb(WB)C

SurfaceSea Temperature C

Temperate Winter -4 N/A 2

Sub-Arctic -10 N/A 1

Arctic -29 N/A 2

c. Internal Temperatures Airconditioned Spaces (unless otherwise specified insubsequent sections):

(1) Tropics:

(a) All compartments, except galley complex, 23.5C EffectiveTemperature (27.0C DB/19.6C WB);

(b) Galley complex, 29C Effective Temperature (34.5C DB/26C WB).

(2) Temperate Summer:

(a) All spaces except the galley complex, 23.5C Effective Temperature(27C DB/19.6C WB);

(b) Galley complex, 25.5C Effective Temperature(29.5C DB/21.5C WB).

(3) All Cold Climates:

(a) All manned spaces unless otherwise specified 22C DB minimum.


4.2

d. Internal TemperaturesVentilated Spaces (unless otherwise specified insubsequent sections):

(1) All Hot Climates:

(a) All spaces, except galleys where the TACS concept is not required,unmanned electrical compartments, main and large auxiliarymachinery spaces, compartment temperature above weatherambient temperature;

(b) Galleys, etc., and unmanned electrical compartments, the spacetemperature restricted to 10C above weather ambient.

(c) Main and large auxiliary machinery spaces, in open ship condition,temperature rise above external ambient restricted to 15C. (forclosed down condition, see Section 8).

(2) All Cold Climates:

(a) All spaces, in all operating conditions, 13C DB minimum.

(b) Main and large auxiliary machinery spaces, in the deadshipcondition, 10C DB minimum, i.e. alongside with only hotel servicesrunning.

4.2 Cooling and Heating Assumptionsa. The cooling and heating loads for each compartment are to be assessed on the

basis of the following assumptions:

(1) Cooling conditions:

(a) Solar radiation occurs on exposed surfaces, weatherdecks and bothsides of the ship simultaneously except for compartments extendingthe full width of the vessel when solar radiation is to be assumed onone side only;

(b) No shade is cast by superstructure, funnels, masts, etc.;

(c) Internal wild heat sources are at maximum value, excludingstandby equipments;

(d) Maximum number of personnel are in each compartment,considered individually. Number of personnel in dining halls,recreation spaces, ward rooms and ante rooms, etc., are to be themaximum likely to attend film shows and functions, as appropriate;

(e) Should the ship be fitted with current inservice equipment then inany compartment the heat gained from the fan and fan motor isequal to 14% x sum of cooling sensible heat gains for thatcompartment However, should the equipment fitted be to goodcommercial marine standards then this figure would revert to 7%;

(f) Although it is specified in Clause 4.2a(1)(d) above that themaximum number of personnel be allowed for when calculatingcooling loads on an individual compartment basis, this would resultin an overall cooling capacity for numbers far in excess of the shipscomplement. Therefore, on completion of cooling calculations, theduplication of manning levels should be determined and the overallcooling capacity reduced accordingly. Allowances for heat gainsfrom personnel are given in Clause 4.3.e.


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4.3

(2) Heating conditions:

(a) Internal wild heat sources are at minimum value, i.e. maximumvalue 40%;

(b) No heat gained from personnel;

(c) No heat gained from adjacent compartments where the maintainedtemperature is non specific;

(d) No heat gained from solar radiation;

(e) Heat gained from fan and fan motor is the same as for coolingconditions;

(f) Heat is lost to adjacent cooler spaces;

(g) Heat is lost through the superstructure to sea and air.

4.3 Total Heat Transfer Coefficient k

a. Total heat transfer coefficients are to be calculated in accordance with theformula quoted in ISO 7547 (Clause 5.2.4) using the thermal conductivities forcommon materials as given in Annex B of that standard and/or publicationsfrom BSRIA or CIBSE. The Table 2 figures given in the ISO as typical heattransfer coefficients for various types of boundaries are not to be used for RNships, as insulation materials, thicknesses and standards can vary considerably.For Cold and Cool rooms see NES 111.

b. The wild heat generated by equipments is to be based upon the actual powerratings obtained from the equipment manufacturers. In the early stages of thedesign such information is not always available and it will be necessary to makethe best possible estimates, e.g. ruleofthumb methods such as the values givenin the following table for the heat gain from compartment lighting:

Compartment Heat gain from general lighting (W/m2)pType Incandescent Flourescent

Cabins, etc. 15 8

Mess or dinning rooms 20 10

Gymnasiums, etc. 40 20

c. When calculating the maximum heat load generated by galley equipment thefollowing criteria is to be used:

(1) From the galley equipments maximum electrical power inputs andemploying diversity factors of 0.2 for thermostatically controlled itemsand 0.5 for manually switched heat controlled items, also assessing themaximum projected usage of equipment, a peak power input figure isarrived at, e.g.

Shallow fryers 15.0 kW input@ 0.2 = 3.0 kW

Deep fryers 30.0 kW input@ 0.2 = 6.0 kW

Hot plate/ovens 50.0 kW input@ 0.5 =25.0 kW

Grilles 6.0 kW input@ 0.5 = 3.0 kW


4.4

Tilting kettles 20.0 kW input@ 0.5 =10.0 kW

Other items 20.0 kW input@ 0.5 =10.0 kW

Total diversified input =57.0 kW

d. This diversified electrical power input is then to be converted into a heatemission into the galley and this is arrived at by using a further diversity factorof 50%, e.g. total diversified input of 57.0 kW = 57.0 x 50% = 28.5 kW heatemission.

e. The wild heat generated by personnel is to be taken as:

Sensible heat = 45 Watts/man;

Latent heat = 135 Watts/man.

f. When separate sleeping and recreational areas are contained within a singlemess deck the above allowances are to be increased to 55 Watts and 165 Wattsrespectively.

4.4 Relative Humidity

a. In airconditioned compartments, in all climatic conditions, the design relativehumidity is to always lie between 65% and 30%. In accommodation and mannedoperational spaces a lower limit of 45% is to be applied and only in veryexceptional circumstances is the RH to fall below this figure.

4.5 Air Distribution Systems

4.5.1 Design Margin

a. When selecting fans for airconditioning and ventilation systems the design airvolume is to be increased by a 10% margin, calculated on the system constantorifice line (See Section 10). Trunk sizing calculations are then to be carried outusing the design air flow and the related total fan pressure as indicated by theconstant orifice line.

4.5.2 Air Velocities

a. In airconditioning and ventilation systems serving operational, habitationalaccommodation, office spaces and other manned working areas the trunked airvelocities are generally to observe the following criteria :

Initial design velocity 10 m/s;

Maximum permissible velocity 12.5 m/s.

b. In compartments or spaces with low noise target levels every effort should bemade to ensure that duct configurations are so designed that velocities areretained at levels which would not result in noise generation.

c. Compartments other than those indicated above where noise target levels arenot as restrictive may be served by airconditioning and ventilation systemswith higher velocities to facilitate space restrictions.

d. The maximum design air velocities through various types of aperture are to beas follows:

(1) Recirculation grilles in bulkheads 2.5 m/s calculated on the clear area;


March 2000

4.5

(2) Supply inlets and exhaust outlets with the exception of spray eliminatingjalousies 5 m/s calculated on the clear area;

(3) Spray eliminating jalousies 5 m/s calculated on the face area;

(4) Slotted trunks, (supply and exhaust):

(a) Vertical velocity through slot 4 m/s;

(b) Horizontal velocity through slot 10 m/s.

(5) Punkah louvres, diffusers, linear grilles, etc., discharge velocity 3 m/s;

(6) Flame proof gauze 5 m/s calculated on the clear area;

(7) Dust filters 2.5 m/s.

e. The maximum face velocity of air passing through a CW/air heat exchangerwithout a moisture eliminator fitted is to be restricted to 2.0 m/s. Moistureeliminators should not be fitted unless absolutely necessary, however if one is tobe fitted then the face velocity across the heat exchanger can be increased to amaximum of 3.0 m/s.

4.5.3 Fresh/Filtered Air Requirements

a. Within the NBCD citadel the fresh air requirement is to be individuallyassessed for each NBCD/fire zone and is to be sufficient to:

(1) Overcome the calculated uncontrolled leakage and thereby generate thespecified zone pressure. This is to be calculated based on an allowance of900 m3/hr of filtered fresh air for every 3,400 m3 of citadel volume abovethe deep water line;

(2) Overcome the known controlled purging exhaust requirements in a openship condition;

(3) Overcome the known controlled purging exhaust requirements in aclosed ship condition;

(4) Purge Cleansing Stations giving specified number of air changes perhour;

(5) Purge AirLocks giving specified number of air changes per hour;

(6) Replenish oxygen levels and thereby keep CO2 content below maximumpermitted levels (See Section 9 Clause 9.4.3);

(7) Overcome the air lost from the citadel other than purging requirements.The amount of filtered fresh air required will therefore be the greater ofthe sum of 2 + 6 + 7 in an open ship condition or the sum of 1 + 3 + 4 + 5+ 6 + 7 in a closed ship condition.

Details of the above calculations are also shown in Section 9.

b. In machinery spaces, when required, under closed down conditions, sufficientfresh air is to be provided to compensate for known controlled losses andcalculated uncontrolled leakages while maintaining a differential pressure ofapproximately 3 millibars (mbars) relative to the external atmosphere.


4.6

c. To prevent ingress of smoke or fumes, selected essential compartments are to bepressurised to between 1 and 1.5 mbars, relative to their surrounding spacesand automatic closures are to be fitted at any recirculation openings and nonreturn features incorporated in the branch trunks supplying these spaces.

4.5.4 Standard NBC Filters

a. The air flow through a single Standard Radial NBC Filter is to be 300 m3/hr 10%.

b. The number of Standard Radial NBC Filters required in an AFU is to becalculated by dividing the total air flow required from the AFU by 300 and,where necessary, rounding up.

4.6 Pressurization

4.6.1 Citadel and Zones

a. Within the NBCD citadel, in the fully closed down condition with citadel andzonal boundaries secured with Air Lock and Cleansing Station disciplinesenforced, the over pressure in any fire/smoke zone, relative to the externalatmosphere, is to be between 5 mbars and 8 mbars. This will be achieved by theuse of nonreturn air bleed valves at Air Locks, Cleansing Stations and otherlocations where controlled leakage is required. Air bleed valves may also benecessary to relieve any overpressure created by the calculated uncontrolledleakage being overestimated, i.e. in the event of the vessel being built tight.With the proper allocation and setting of the above air bleed valves thedifferential pressure between adjacent fire/smoke zones will not exceed theallowed 0.5 mbars.

4.6.2 Machinery Spaces

a. In a main machinery space where an overpressure is to be generated in a fullyclosed down ship, the said overpressure shall be 3 mbars relative to theexternal atmosphere. These machinery spaces will normally be cooled by airrecirculating through CW/air heat exchangers and will have a fresh air supplysufficient to balance the sum of any known controlled leakages to suit exhaustpurging requirements and the calculated uncontrolled leakages based on theallowance of 0.5air changes per hour on the gross volume, including casings ifopen to the machinery space. In exceptional circumstances where spacerestrictions on the vessel preclude the addition of dedicated Air Filtration Unitsand fresh air supplied to the ships citadel is sufficient, then the fresh airrequired to pressurise the machinery space may be bled off from the citadel,with the proviso that all fire protection requirements are met and the integrityof the citadel is maintained.

4.7 Heating Systems

a. The minimum temperature of fresh air supplied direct to compartments andspaces within the citadel is to be 13C.


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4.7

b. In airconditioning systems the temperature of the mixed fresh andrecirculated air before the inlet to main heater or fan, whichever is appropriate,is not to fall below 4.5C in cold climates.

c. In grouped systems where one heater may serve several compartments thevariation in the design supply temperatures is not to be more than 3C.

d. The maximum temperature at which air is to be supplied to any compartment is32C.

e. In compartments within the NBCD citadel both the airconditioned andmechanically exhausted air flows used when heating, are to be the same as thosecalculated for cooling.

f. In cold climates, in compartments outside of the NBCD citadel which do nothave a stated minimum air change requirement, the air volumes delivered bymechanical ventilation systems to maintain temperatures below specificmaximums in hot climates are to be reduced by 50% or to 0.005 m3/s per man,whichever is the greater.

4.8 Chilled Water Systems

4.8.1 Design Margins

a. CWP for both essential and nonessential systems are to provide a preselectedgrowth margin calculated on the total connected cooling load of the system (SeeSection 6 for the method of selecting CWP).

b. CW pumps are to be selected to provide a flow capacity 10% greater than thecapacity of the plant it serves.

c. Pipe connections between CWP, CW pumps, main risers, distribution mains andpipe leads to backup water/water heat exchangers for essential systems are to beincreased by at least one standard nominal diameter over the calculated designsize.

d. Water/water backup heat exchangers, for essential systems, are to be capable ofcoping with the appropriate system design connected cooling load plus a growthmargin of 25%.

4.9 Chilled Water Temperatures

a. The design temperatures at the CWP are:

(1) Supply to heat exchangers 6.5C;

(2) Return from heat exchangers (full load) 13.5C.

b. In nonessential systems, served by two or more CWP, the mixing maintemperature on light load is not to be greater than 9C.

c. In essential systems the CW is to be supplied to the heat exchangers servingweapons cabinets and other electrotechnical equipments at a temperature of9C 2C.


4.8

4.10 Velocities and Pipe Size

a. In all systems the CW flow is to be within the limits of 4.5 m/s and 2.0 m/s andthe minimum pipe diameter is to be 16 mm. In exceptional cases, possibly wherea bank of electronic cabinets is to be served, these requirements may beincompatible due to the small quantities of CW needed. In such circumstancesconsideration is to be given to connecting the heat exchangers in series andadjusting the CW flows to obtain the necessary cooling.


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5.1

5. AIR DISTRIBUTION SYSTEMSRelated Documents: ISO 9785, NES 101 Part 2, NES 111, NES 121, NES 123 Part 1,NES 183 Part 1, NES 519, NES 593, NES 763, NES 1004, BR 1754, Form SSCF 4; seealso Annex A.

5.1 Design Objectivea. The design of the total air distribution system for any vessel is to ensure that:

(1) Noxious odours, toxic and dangerous fumes, and other contaminants arewithin the permitted Health and Safety concentrations and areconstrained in specific compartments;

(2) Acceptable oxygen levels are maintained for personnel efficiency,combustion and other oxidation processes;

(3) In a fire situation, smoke migration is restricted to defined zones and postfire contamination is cleared with minimal loss of operationaleffectiveness;

(4) A positive pressure, relative to the external atmosphere, can be achievedand maintained within the NBCD citadel and machinery spaces whenrequired;

(5) Watertight, gastight and smoketight integrity is not impaired;

(6) Air is distributed as best suited to particular compartment functionspersonnel comfort and equipment cooling;

(7) Acceptable compartment conditions are maintained at all times inmanned compartments.

5.2 General Requirements

a. Exhaust discharge openings are to be sited well clear of any potential sources ofignition or reingestion, the exhaust outlets being on the opposite side of the shipto supply inlets. Where this is not possible, the positioning and protection ofweatherdeck inlets to AFU, ventilation systems, compressors, etc., is to ensurethat no foul air is drawn in from nearby exhausts.

b. Exhaust outlets are not to be positioned to discharge across walkways.

c. All weatherdeck openings, where appropriate, are to be fitted with sprayeliminators and self draining terminals that will cope with the most extremeenvironmental conditions and satisfy the relevant standards specified inNES 1004.

d. Where practicable, all weatherdeck ventilation openings to systems servingcompartments within the NBC citadel, with the exception of inlets to AFU, areto be fitted with a butterfly valve sited in the trunk leading from the openingand as close to the ships side as possible. Trunking between the ships side andthe valve is to be gas tight (See also Clause 11.8.e).

e. Weatherdeck openings to systems serving compartments outside of the citadelare to be fitted with butterfly valves as above (See also Clauses 11.8.f and11.8.g).

f. Filters are to be fitted to prevent fan systems and equipment being coated withairborne dust and fibres, resulting in reduced performance and possibleblockage (For details of siting and types of filters see Section 12).


5.2

g. Easy access arrangements are to be provided throughout all systems to allowducting to be internally inspected and cleaned. This is especially importantwhere trunking is subject to high fouling rates, e.g. galley, laundry, bathrooms,WC, etc.

h. In airconditioned and mechanically ventilated spaces (except for mainmachinery spaces) linear grilles, punkah louvres or diffusers, as appropriate,are to be fitted in supply trunking, routed within the compartment, to providean even distribution to manned positions and to disperse wild heat.

i. Where the majority of the distribution diffusers on a system can be closed by theoccupants, a pressure relief valve is to be fitted in the ATU downstream of thefan discharge.

j. Trunked exhaust and recirculation terminals within the spaces served aregenerally to be linear grilles or similar. Recirculation from spaces to passages isto be via light tight grilles incorporated in escape panels, suitably protectedopenings in bulkheads or 30 mm air gap at top or bottom of doors, asappropriate.

k. ATU and AFU are to be sited within the NBCD/fire zone that contains thecompartments they serve.

l. Free flow recirculation routes are to be unobstructed and are not to rely upondoors and hatches in watertight boundaries remaining open. Watertight risk,damage control and NBCD markings are not to be compromised to obtain airflow routes but in extreme cases valved, watertight jumper trunks are to befitted to bridge decks and watertight bulkheads.

m. Voids formed between linings and deckheads are not to be used in lieu of supply,exhaust or recirculation trunks and they are not to be considered asunobstructed for the free flow of recirculated air. Recirculation grilles fitted indeckhead linings are to be trunked to the nearest passage bulkhead andterminated in a suitably screened opening.

n. All access openings between NBCD citadel and machinery spaces and betweenNBCD citadel and external atmosphere, that are required in the closed downcondition are to be protected by Cleansing Stations or Air Locks. CleansingStations and citadel accesses to the weatherdecks are to have the Air Locks airpurged (See Section 9).

o. Within the citadel, in both the open ship and closed ship condition, eachNBCD/fire zone is to have a balanced supply and exhaust. It is essential that airdoes not flow across zonal boundaries in the open ship condition when accessis allowed between zones through boundary doors.

p. For air distribution within machinery spaces (See Section 8).

5.3 Air-conditioning Arrangements

a. Conditioned air is to be distributed via essential and nonessential ATU each ofwhich is to consist of a 25 mm thick filter protecting an appropriate fan andair/CW cooling coil engineered as a package.

b. Condensation collection and drainage arrangements are to be provided. Thedrainage system must be effective against all levels of static air pressuregenerated at the cooling coil and must not be dependent upon manual primingof a dry system.


March 2000

5.3

c. If there is a risk of condensation carry over into the distribution system,moisture eliminators are to be fitted.

d. Air is to be distributed to, and within, compartments by trunking connected tothe fan outlet. The recirculation of air back to the ATU inlet can either beopen (i.e. the ATU inlet is open directly to the compartment in which it issituated) or trunked, depending upon the type of compartment being servedand the position of the ATU.

e. ATU are to be identified as either Central ATU or Compartment ATU and theselection of a type for a particular duty is to be based upon the followingcharacteristics.

5.4 Central ATU

a. Are to be fitted in dedicated compartments, sited centrally within particularfire zones, with other fans that serve spaces within that particular zone.

b. Are to serve all essential systems.

c. Are to serve all nonessential group systems that supply more than onecompartment or compartment complex.

d. Fresh air for ATU with open recirculation is to be trunked to the ATUcompartment which is to act as a mixing chamber for these systems. Wheretrunked recirculation is fitted the fresh air is to be delivered into therecirculation trunk upstream of the filter to ensure the air is thoroughly mixedbefore it passes over the cooling coil.

5.5 Compartment ATU

a. Are to serve only nonessential, single compartments or compartmentcomplexes where the space available and cooling load make them appropriate,e.g. Dining Hall, Recreation Spaces, Laundry, Sick Bay, etc.

b. The filter, fan, cooling coil and if required, moisture eliminator are to bepackaged and enclosed in a suitable container to be sited within thecompartment served.

c. Local controls are to be provided to enable ATU performance to be matched tocompartment conditions.

d. Where convenient the main heater with local controls is to be included in theATU package.

e. The fresh air required by the compartment is to be trunked direct from the AFUto the ATU or adjacent to the enclosure.

NOTE When designing, and installing Compartment ATU it is emphasized that:

(1) The noise and vibration standards appropriate to the compartmentserved must be achieved;

(2) Condensation must be contained, collected and removed withoutmigrating into the compartment and on no account are CW pipes to be ledover living, sleeping, eating areas, etc.


5.4

5.6 ATU Controls

a. Where the cooling load on any ATU can vary significantly, either in the shortterm, due to the movement of personnel or change in equipment status, or inthe long term, due to changes in climate, controls are to be provided at the ATUthat will allow the cooling performance to be matched to the compartmentconditions.

b. The required control is to be achieved by restricting:

(1) The flow of CW through the cooling coil;

or

(2) The flow of cooled air to the compartment(s) using variable volume fans;

or

(3) A combination of both options.

c. Where control is achieved by restricting the air flow, care is to be taken that theminimum velocity across electrical heaters is maintained to avoid constantlytripping and that with compartments fully manned, the CO2 content of the airdoes not rise above permitted maximum levels.

d. Reduction in CW flow is to be achieved by fitting thermostatically controlled,three way, diverter valves in the ATU control panel (See Section 6).

e. Details of main heater controls are given in Section 8.

5.7 Special Requirements

5.7.1 Operational Spaces

a. These essential spaces are to be airconditioned with open recirculation back toan ATU. The fresh air requirement is to be trunked to the ATU and therequirements of Clause 5.6.a considered.

b. Supply terminals giving directional control of the air flow are to be sited atmanned positions with diffusers or similar terminals positioned to disperseheat from equipments.

c. To prevent smoke entering selected Essential compartments in a fire situation,a positive pressure of 1 to 1.5 mbars relative to the surrounding spaces is to bemaintained. Non return air bleed valves can be fitted to the recirculation grillesand shut off features incorporated on the ATU supply system serving thecompartment to restrict smoke entry when the fans are stopped.

5.7.2 Accommodation and Recreation Spaces

a. These spaces are to be airconditioned with open recirculation back to an ATU.The fresh air requirement is to be trunked to the ATU and the requirements ofClause 5.6.a implemented.

b. For combined sleeping and recreation spaces:

(1) Of the total air supplied to the space, 80% is to be supplied direct to thesleeping area and 20% direct to the recreation area;


March 2000

5.5

(2) The total recirculation is to be taken from the recreation area only, so thatall the air supplied to the sleeping area will pass through the recreationarea;

(3) A controllable air flow of between 0.005m3/s and 0.01m3/s is to beprovided to each bunk, the total quantity supplied to bunks being at least50% of the total air flow delivered to the sleeping area. The remaining airsupplied to the sleeping area is to be evenly distributed throughout thecompartment.

c. For cabins and sleeping areas:

(1) Where more than one bunk is fitted an individual, controllable, air flow of0.005m3/s and 0.01m3/s is to be provided to each sleeping position, theremainder of the air being distributed evenly throughout thecompartment;

(2) In single berth cabins an even distribution of cooled air is to be providedby linear grilles or diffusers.

5.8 Medical Spaces

5.8.1 Sick Bays

a. Sick bay complexes are to be airconditioned by dedicated ATU with fullytrunked distribution, fresh air, recirculation and where necessary, exhaustsystems. The Medical Complex is to maintain a positive pressure in relation toadjacent compartments surrounding the complex in order to prevent theingress of any possibly contaminated air thereby ensuring sterility. Similarlythe Operating Theatre is to have a relative positive pressure in relation to theadjacent Medical Compartments. Fresh air make up is to be via a NBC AFUwith bypass arrangements. Sick bays are to be served by one of two systemconfigurations, the particular one being chosen by the size, type and number ofcompartments involved.

b. Temperatures within the Complex are to be maintained as follows:

(1) Heating 22C DB minimum 1C;

(2) Cooling 23.5C Effective Temperature (27C DB/19.6C WB/RH 50%).

c. The ambient temperature in some compartments, typically the OperatingTheatre, Treatment Room/Dispensary and Surgery is to be capable of beingquickly adjusted by the surgeon as dictated by the patients condition.Designated compartments and temperature ranges required ar

def stan 02 - 102 - air condition & ventilation

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