Building services engineering, Lecture notes of Civil Engineering

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Building Services Engineering

Building Services Engineering

Fifth edition

David V. Chadderton

First edition published 1991 by E & FN Spon Second edition published 1994 Third edition published 2000 Fourth edition published 2004

Fifth edition published 2007 by Taylor & Francis 2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN

Simultaneously published in the USA and Canada by Taylor & Francis 270 Madison Ave, New York, NY 10016

Taylor & Francis is an imprint of the Taylor & Francis Group, an informa business

© 1991, 1994, 2000, 2004, 2007 David V. Chadderton

All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers.

The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any efforts or omissions that may be made.

British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library

Library of Congress Cataloging in Publication Data Chadderton, David V. (David Vincent), 1994– Building services engineering / David V. Chadderton. – 5th ed. p. cm. Includes bibliographical references and index.

1. Buildings – Mechanical equipment. 2. Buildings – Environmental engineering. I. Title. TH6010.C4867 2007 696–dc22 2006030849

ISBN10: 0–415–41354–0 (hbk) ISBN10: 0–415–41355–9 (pbk) ISBN10: 0–203–96299–0 (ebk)

ISBN13: 978–0–415–41354–1 (hbk) ISBN13: 978–0–415–41355–8 (pbk) ISBN13: 978–0–203–96299–2 (ebk)

This edition published in the Taylor & Francis e-Library, 2007.

“To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk.”

ISBN 0- 203 - 96299 - 0 Master e-book ISBN

• 1 Built environment Symbols xvi
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • World energy supply and demand
  • The building as an environmental filter
  • Basic needs for human comfort
  • Comfort equation
  • Comfort measurement
  • External environments
  • Environmental measurements
  • Environmental temperature
  • Operative temperature
  • Comfort criteria
  • Experimental work
  • Questions
• 2 Energy economics
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Energy audit
  • Unity brackets
  • Gross calorific value of a fuel
  • Energy cost per useful gigajoule
  • Greenhouse gas
  • Annual energy costs
  • Economic thickness of thermal insulation vi Contents
  • Accounting for energy-economizing systems
  • Low-energy buildings
  • The effect on gas consumption of thermal insulation in houses
  • Questions
• 3 Heat loss calculations
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Thermal resistance of materials
  • Thermal transmittance ( U value)
  • Heat loss from buildings
  • Boiler power
  • Thermal transmittance measurement
  • Questions
• 4 Heating
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Heating equipment
  • Hot-water heating
  • Oil-firing equipment
  • Combustion
  • Flues
  • Performance testing
  • Electrical power generation
  • Combined heat and power
  • District heating
  • Building energy management systems
  • Geothermal heating
  • Questions
• 5 Ventilation and air conditioning
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Ventilation requirements
  • Natural and mechanical systems
  • Removal of heat gains
  • Psychrometric cycles
  • Air-conditioning systems
  • Vapour-compression refrigeration
  • Absorption refrigeration cycle
  • Ventilation rate measurement
  • Materials for ventilation ductwork
  • Chlorofluorocarbons
  • Sick building syndrome Contents vii
  • Air temperature profile
  • Questions
• 6 Hot- and cold-water supplies
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Water treatment
  • Base exchange
  • Cold-water services
  • Hot-water services
  • The indirect hot-water system
  • Pipe sizing
  • Allocation of sanitary appliances
  • Materials for water services
  • Solar heating
  • Questions
• 7 Soil and waste systems
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Definitions
  • Fluid flow in waste pipes
  • Pipework design
  • Discharge unit pipe sizing
  • Materials used for waste and discharge systems
  • Testing
  • Maintenance
  • Questions
• 8 Surface-water drainage
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Flow load
  • Roof drainage
  • Disposal of surface-water
  • Questions
• 9 Below-ground drainage
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Design principles
  • Access provision
  • Materials for drainage pipework
  • Sewage-lifting pump viii Contents
  • Testing
  • Questions
• 10 Condensation in buildings
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Sources of moisture
  • Condensation and mould growth
  • Vapour diffusion
  • Temperature gradient
  • Dew-point temperature gradient
  • Installation note
  • Questions
• 11 Lighting
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Natural and artificial illumination
  • Definition of terms
  • Maintenance
  • Utilization factor
  • Glare and reflections
  • Lumen design method
  • Air-handling luminaires
  • Colour temperature
  • Lamp types
  • Control of lighting services
  • Questions
• 12 Gas
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Gas pipe sizing
  • Gas service entry into a building
  • Flue systems for gas appliances
  • Ignition and safety controls
  • Questions
• 13 Electrical installations
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Electricity distribution
  • Circuit design Contents ix
  • Cable capacity and voltage drop
  • Construction site distribution
  • Safety cut-outs
  • Electrical distribution within a building
  • Conduit and trunking
  • Testing
  • Telecommunications
  • Lightning conductors
  • Graphical symbols for installation diagrams
  • Questions
• 14 Room acoustics
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Acoustic principles
  • Sound power and pressure levels
  • Sound pressure level
  • Absorption of sound
  • Reverberation time
  • Plant sound power level
  • Transmission of sound
  • Sound pressure level in a plant room
  • Outdoor sound pressure level
  • Sound pressure level in an intermediate space
  • Sound pressure level in the target room
  • Noise rating
  • Questions
• 15 Fire protection
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Fire classification
  • Portable extinguishers
  • Fixed fire-fighting installations
  • Fire detectors and alarms
  • Smoke ventilation
  • Questions
• 16 Plant and service areas
  • Learning objectives
  • Key terms and concepts
  • Introduction
  • Mains and services
  • Plant room space requirements
    • Service ducts x Contents
    • Pipe, duct and cable supports
    • Plant connections
    • Coordinated service drawings
    • Boiler room ventilation
    • Questions
• 17 Mechanical transportation - Learning objectives - Key terms and concepts - Introduction - Transportation systems - Questions
• 18 Question bank - Learning objectives - Key terms and concepts - Introduction - Question bank
• 19 Understanding units - Learning objectives - Key terms and concepts - Introduction - Questions
  • Appendix: answers to questions
  • References
  • Index

xii Preface to fifth edition

will also find the book useful. The advanced user will need to progress to specialized text books

and the standard references.

The reader is challenged to become actively engaged in the design calculations carried out

by design engineers, through step-by-step introduction of each stage. A standard of numerical

competence is expected that some lecturers may consider being higher than is necessary for some

courses. This was deemed appropriate in order to broaden the potential readership and provide

an adequate basis for a deeper design study.

Readers are encouraged to make use of the internet as a learning resource. Graphics included

in a printed book are there to explain a basic principle. Use a search engine to view real plant

items such as steel panel heating radiators, pumps, air-handling units, fire extinguishers or lifts,

as needed. For example, a search for Wartsila takes the enquirer straight to the manufacturer of

the geothermal heating CHP equipment. Happy surfing!

Acknowledgements

I am particularly grateful to the publishers for their investment in much of my life’s work.

Such a production only becomes possible through the efforts of a team of highly professional

people. An enthusiastic, harmonious and efficient working relationship has always existed, in

my experience, with Taylor & Francis. All those involved are sincerely thanked for their efforts

and the result. My wife Maureen is thanked for her encouragement and understanding while

I have been engrossed in keyboard work, on the drawing board and shuffling through piles of

proofs. I would specifically like to thank those who have refereed this work. Their efforts to ensure

that the book has comprehensive coverage, introductory work, adequate depth of study, valid

examples of design, good-structured worked examples and exercises are all appreciated. Users

and recommenders of the book are all thanked for their support; without them, it would not exist.

The psychrometric chart, Fig. 10.1, has been reproduced by permission of the Chartered

Institution of Building Services Engineers. Pads of charts, for calculation purposes, may be

obtained from CIBSE, Delta House, 222 Balham High Road, London SW12 9BS, UK.

Units and constants xv

Table 2 Multiples and submultiples.

Quantity Name Symbol

10 12 tera T 109 giga G 106 mega M 103 kilo k 10 −^3 milli m 10 −^6 micro μ

Table 3 Physical constants.

Gravitational acceleration g 9.807 m/s^2 Specific heat capacity of air SHC 1.012 kJ/kgK Specific heat capacity of water SHC 4.186 kJ/kgK Stefan–Boltzmann constant σ 5.67 × 10 −^8 W/m 2 K^4 Density of air at 20◦C, 1013.25 rnb ρ 1.205 kg/m^3 Density of water at 4◦C ρ 103 kg/m^3 Exponential e 2.

Symbols

Symbol Description Units

A area m^2 electrical current A A f floor area m^2 physical constant dB A g cross-sectional area of gutter mm^2 A o area of water flow at gutter outlet mm^2 A r roof area m^2 A w walling area m^2 α (alpha) electrical temperature coefficient of resistance
/
◦C percentage depreciation and interest charge % absorption coefficient dimensionless α ¯ mean absorption coefficient dimensionless AET allowed exposure time min B building envelope number sound reduction index dB B f physical constant dB b barometric pressure bar, b β (beta) angle degree C fuel cost per appropriate unit carbon C 1 , C 2 constant C i interior air pollution decipol C o outdoor air pollution decipol C r room concentration % C s supply air concentration % C T concentration after time T % C 3 electrical load W/m 2 clo clothing thermal insulation C v ventilation coefficient CO 2 carbon dioxide %, ppm D gutter depth mm DI directivity index dB DU demand or discharge unit d pipe diameter m or mm distance m

xviii Symbols

Continued

Symbol Description Units

NR noise rating dimensionless n f number of storeys olf concentration of odorous pollutants
(omega) electrical resistance ohm P pressure pascal permeance kg/Ns P carbon dioxide production Pa pressure pascal P 1, P 2 area fraction PD percentage of occupants dissatisfied % p s vapour pressure pascal φ (phi) angle degree Q fluid flow rate m^3 /s or l/s power kW geometric directivity factor dimensionless Q c convection heat transfer W Q e extract air flow rate m^3 /s Q ex exhaust air flow rate m^3 /s Q f fresh air flow rate m^3 /s Q f fabric heat loss W Q HWS hot water service power kW Q L leakage air flow rate m^3 /s Qp total heat requirement W Q r radiation heat transfer W recirculation air flow rate m^3 /s Q u heat flow through fabric W Q v ventilation heat loss W q water flow rate kg/s R resistance, electrical
thermal m^2 K/ W room sound absorption constant m^2 R A combined resistance of pitched roof m^2 K/ W R a air space thermal resistance m^2 K/ W R B ceiling thermal resistance m^2 K/ W R n new thermal resistance m^2 K/ W R si internal surface thermal resistance m^2 K/ W R so outside surface thermal resistance m^2 K/ W R R thermal resistance of roof void m^2 K/ W R v vapour resistance Ns/kg r distance m r v vapour resistivity GN s/kgm MN s/gm ρ (rho) density kg/m^3 specific electrical resistance
m soil electrical resistivity
m S spacing m length of heating season days surface area m^2 s time second SC quarterly standing charge SE specific enthalpy kJ/kg SG specific gravity SH sensible heat transfer kW

Symbols xix

Symbol Description Units

SPL sound pressure level dB SWL sound power level dB SRI sound reduction index dB SHC ∑ specific heat capacity kJ/kgK summation T absolute temperature kelvin total demand target reverberation time s τ (tau) time interval T E electrical demand target T T thermal demand target t a air temperature ◦C t ai inside air temperature ◦C t ao outside air temperature ◦C t b base temperature ◦C t c operative temperature ◦C t dp dew-point temperature ◦C t e environmental temperature ◦C t ei internal environmental temperature ◦C t eo outside environmental temperature ◦C t f water flow temperature ◦C t g globe temperature ◦C t HWS hot-water storage temperature ◦C t m mean water temperature ◦C area-weighted average room surface temperature ◦C t max maximum air temperature ◦C t min minimum air temperature ◦C t 15 air temperature at time θ = 15 h ◦C t r mean radiant temperature ◦C return water temperature ◦C t res resultant temperature ◦C t s supply air temperature ◦C surface temperature ◦C θ (theta) angle degree time h U thermal transmittance W/m 2 K U e economic thermal transmittance W/m 2 K U n new thermal transmittance W/m 2 K U w wall thermal transmittance W/m 2 K UC useful cost of a fuel £/GJ, p/kWh UF utilization factor V volume m^3 V electrical potential volt v velocity m/s v s specific volume m^3 /kg W width m or mm W power watt w.b. wet-bulb air temperature ◦C w.b. WCI wind chill index Y admittance factor annual degree days