-
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
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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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(i)
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
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NES 102 Part 1Issue 2March 2000
(ii)
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NES 102 Part 1Issue 2
March 2000
(iii)
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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NES 102 Part 1Issue 2March 2000
(iv)
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NES 102 Part 1Issue 2
March 2000
(v)
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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NES 102 Part 1Issue 2March 2000
(vi)
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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NES 102 Part 1Issue 2
March 2000
(vii)
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. . . . . . . . . .
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(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. . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .
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NES 102 Part 1Issue 2March 2000
(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. . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
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NES 102 Part 1Issue 2
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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.
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NES 102 Part 1Issue 2March 2000
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.
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NES 102 Part 1Issue 2
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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.
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NES 102 Part 1Issue 2March 2000
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
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NES 102 Part 1Issue 2
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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
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NES 102 Part 1Issue 2March 2000
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.
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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.
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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 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.
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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;
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(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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(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.
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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. 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.
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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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(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
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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;
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(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.
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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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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.
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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).
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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.
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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.
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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;
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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