Heating, ventilating, air conditioning and refrigeration CIBSE Guide B The rights of publication or translation are reserved No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means without the prior permission of the Institution © May 2005 The Chartered Institution of Building Services Engineers London Registered charity number 278104 ISBN 903287 58 This document is based on the best knowledge available at the time of publication However no responsibility of any kind for any injury, death, loss, damage or delay however caused resulting from the use of these recommendations can be accepted by the Chartered Institution of Building Services Engineers, the authors or others involved in its publication In adopting these recommendations for use each adopter by doing so agrees to accept full responsibility for any personal injury, death, loss, damage or delay arising out of or in connection with their use by or on behalf of such adopter irrespective of the cause or reason therefore and agrees to defend, indemnify and hold harmless the Chartered Institution of Building Services Engineers, the authors and others involved in their publication from any and all liability arising out of or in connection with such use as aforesaid and irrespective of any negligence on the part of those indemnified Typeset by CIBSE Publications Printed in Great Britain by Page Bros (Norwich) Ltd., Norwich, Norfolk NR6 6SA Note from the publisher This publication is primarily intended to provide guidance to those responsible for the design, installation, commissioning, operation and maintenance of building services It is not intended to be exhaustive or definitive and it will be necessary for users of the guidance given to exercise their own professional judgement when deciding whether to abide by or depart from it Contents Heating 1-1 1.1 Introduction 1-1 1.2 Strategic design decisions 1-1 1.3 Design criteria 1-4 1.4 System selection 1-12 1.5 Plant and equipment 1-26 1.6 Fuels 1-53 References 1-58 Appendix 1.A1: Example calculations 1-62 Appendix 1.A2: Sizing and heights of chimneys and flues 1-67 Ventilation and air conditioning 2-1 2.1 Introduction 2-1 2.2 Integrated approach 2-1 2.3 Requirements 2-12 2.4 Systems 2-50 2.5 Equipment 2-106 References 2-133 Appendix 2.A1: Techniques for assessment of ventilation 2-140 Appendix 2.A2: Psychrometric processes 2-142 Ductwork 3-1 3.1 Introduction 3-1 3.2 Strategic design issues 3-3 3.3 Design criteria 3-9 3.4 System Selection 3-26 3.5 Ductwork materials and fittings 3-36 3.6 Testing and commissioning 3-38 3.7 Maintenance and cleaning 3-41 References 3-45 Bibliography 3-46 Appendix 3.A1: Recommended sizes for ductwork 3-48 Appendix 3.A2: Space allowances 3-51 Appendix 3.A3: Maximum permissible air leakage rates 3-53 Appendix 3.A4: Summary of fan types and efficiencies 3-54 Appendix 3.A5: Methods of fire protection 3-54 Appendix 3.A6: Example calculations 3-55 Refrigeration and heat rejection 4-1 4.1 Introduction 4-1 4.2 Design strategies 4-1 4.3 Requirements 4-9 4.4 System selection 4-18 4.5 Equipment 4-41 References 4-53 Index Appendix 4.A1: Summary data for refrigerants 4-56 Appendix 4.A2: Pressure–enthalpy charts for refrigerants 4-57 Noise and vibration control for HVAC 5-1 5.1 Introduction 5-1 5.2 Summary of noise and vibration problems from HVAC 5-3 5.3 Noise sources in building services 5-5 5.4 Noise control in plant rooms 5-7 5.5 Airflow noise — regeneration of noise in ducts 5-7 5.6 Techniques for control of noise transmission in ducts 5-9 5.7 Room sound levels 5-14 5.8 Transmission of noise to and from the outside 5-20 5.9 Criteria for noise in HVAC systems 5-20 5.10 Noise prediction 5-22 5.11 Vibration problems and control 5-22 5.12 Summary of guidance on noise and vibration control 5-33 References 5-34 Appendix 5.A1: Acoustic terminology 5-35 Appendix 5.A2: Generic formulae for predicting noise from building services plant 5-38 Appendix 5.A3: Interpreting manufacturers’ noise data 5-41 Appendix 5.A4: Basic techniques for prediction of room noise levels from HVAC systems 5-42 Appendix 5.A5: Noise instrumentation 5-45 Appendix A6: Vibration instrumentation 5-46 Appendix A7: Direct and reverberant sound in a room 5-47 Appendix A8: Noise criteria 5-48 I-1 1-1 Heating 1.1 Introduction This Guide starts by considering the strategic choices facing the heating system designer, including the requirements imposed by the intended use of the building, energy and environmental targets, legal requirements and possible interaction with other building services The succeeding sections follow the various stages of design, as follows: — detailed definition of requirements and the calculation of system loads — characteristics and selection of systems — characteristics and selection of system components and equipment — characteristics of fuels and their requirements for storage — commissioning and hand-over Section 1.2, which deals with strategic choices, is relatively broad ranging and discursive and is intended to be read from time to time as a reminder of the key decisions to be taken at the start of the design process The latter sections are sub-divided by topic and are likely to be used for reference, as particular issues arise; they contain a range of useful details but also direct the reader to more specialised sources where appropriate, including other CIBSE publications and BS, EN, and ISO standards When using this Guide, the designer should firstly fully map the design process that is being undertaken The process for each application will be unique, but will follow the general format: — problem definition — ideas generation — analysis, and — selection of the final solution This procedure is illustrated in Figure 1.1 in the form of a outline flowchart 1.2 Strategic design decisions 1.2.1 General In common with some other aspects of building services, the requirements placed upon the heating system depend crucially on the form and fabric of the building It follows that the role of the building services engineer in heating system design is at its greatest when it begins at an early stage, when decisions about the fabric of the building can still be influenced This allows options for heating to be assessed on an integrated basis that takes account of how the demand for heating is affected by building design as well as by the provision of heating In other cases, especially in designing replacement heating systems for existing buildings, the scope for integrated design may be much more limited In all cases, however, the designer should seek to optimise the overall design as far as is possible within the brief A successful heating system design will result in a system that can be installed and commissioned to deliver the indoor temperatures required by the client When in operation, it should operate with high efficiency to minimise fuel costs and environmental emissions while meeting those requirements It should also sustain its performance over its planned life with limited need for maintenance and replacement of components Beyond operational and economic requirements, the designer must comply with legal requirements, including those relating to environmental impact and to health and safety 1.2.2 Purposes of space heating systems Heating systems in most buildings are principally required to maintain comfortable conditions for people working or living in the building As the human body exchanges heat with its surroundings both by convection and by radiation, comfort depends on the temperature of both the air and the exposed surfaces surrounding it and on air movement Dry resultant temperature, which combines air temperature and mean radiant temperature, has generally been used for assessing comfort The predicted mean vote (PMV) index, as set out in the European Standard BS EN 7730 (1), incorporates a range of factors contributing to thermal comfort Methods for establishing comfort conditions are described in more detail in section 1.3.2 below In buildings (or parts of buildings) that are not normally occupied by people, heating may not be required to maintain comfort However, it may be necessary to control temperature or humidity in order to protect the fabric of the building or its contents, e.g from frost or condensation, or for processes carried out within the building In either case, the specific requirements for each room or zone need to be established 1.2.3 Site-related issues The particular characteristics of the site need to be taken into account, including exposure, site access and connection to gas or heating mains Exposure is taken into account in the calculation of heat loss (see section 1.3.3 below) The availability of mains gas or heat supplies is a key factor affecting the choice of fuel 1-2 Heating Examples: Statutory requirements Regulatory requirements Clients functional requirements Occupant thermal comfort Building fabric Examples: Internal temperatures External temperatures Energy targets System fluid temperatures Cost budget Space limitations Electrical loads Structural loadings Acoustics Vibration *Involve the client and the rest of the design team Outline design process Identify the requirements of the system to be designed* Establish the design parameters that relate to the system to be designed Do the parameters comply with legislation, energy targets etc? No Yes Identify possible ventilation approach(es) Produce a preliminary schedule of major items of plant for each option No Can the system work within the parameters? No Yes Yes Identify the preferred system option Select the system components Size the system components Do the components comply with the selected parameters? Yes Complete calculations, generate drawings, schedules and specifications Figure 1.1 Outline design process; heating No Does the design satisfy client requirements for quality, reliability and performance at acceptable cost (value engineering exercise(2)) Strategic design decisions The form and orientation of buildings can have a significant effect on demand for heating and cooling If the building services designer is involved early enough in the design process, it will be possible to influence strategic decisions, e.g to optimise the ‘passive solar’ contribution to energy requirements 1.2.4 Legal, economic and general considerations Various strands of legislation affect the design of heating systems Aspects of the design and performance of heating systems are covered by building regulations aimed at the conservation of fuel and power(3–5) and ventilation(4–6); and regulations implementing the EU Boiler Directive(7) set minimum efficiency levels for boilers Heat producing appliances are also subject to regulations governing supply of combustion air, flues and chimneys, and emissions of gases and particles to the atmosphere (8), see section 1.5.5.1 Designers should also be aware of their obligations to comply with the Construction (Design and Management) Regulations(9,10) and the Health and Safety at Work Act(11) Beyond strictly legal requirements, the client may wish to meet energy and environmental targets, which can depend strongly on heating system performance These include: — CIBSE Building Energy Codes(12) define a method for setting energy targets — Carbon performance rating/carbon intensity: although primarily intended as a means of showing compliance with Part L of the Building Regulations(3), ‘carbon performance rating’ (CPR) and ‘carbon intensity’ may be used more widely to define performance CPR applies to the overall energy performance of office buildings with air conditioning and mechanical ventilation Carbon intensity applies to heating systems generally 1-3 1.2.5 As noted above, the earlier the heating system designer can be involved in the overall design process, the greater the scope for optimisation The layout of the building, the size and orientation of windows, the extent and location of thermal mass within the building, and the levels of insulation of the building fabric can all have a significant effect on demand for heat The airtightness of the building shell and the way in which the building is ventilated are also important Buildings that are very well insulated and airtight may have no net heating demand when occupied, which requires heating systems to be designed principally for pre-heating prior to occupancy (16) However, the designer is often faced with a situation in which there is little or no opportunity to influence important characteristics of the building that have a strong bearing on the heating system, particularly in the replacement of an existing heating system For example, there may be constraints on the area and location of plant rooms, the space for and the routing of distribution networks There may also be a requirement to interface with parts of an existing system, either for heating or ventilation Where domestic hot water is required, a decision is required on whether it should be heated by the same system as the space heating or heated at the point of use 1.2.6 — — Broader ranging environmental assessments also take energy use into account, e.g Building Research Environmental Assessment Method (13) (BREEAM) sets a series of best practice criteria against which aspects of the environmental performance of a building can be assessed A good BREEAM rating also depends strongly on the performance of the heating system Clients who own and manage social housing may also have ‘affordable warmth’ targets, which aim to ensure that low income households will not find their homes too expensive to heat The UK government’s Standard Assessment Procedure for the Energy Rating of Dwellings (14) (SAP) and the National Home Energy Rating (15) (NHER) are both methods for assessing the energy performance of dwellings Economic appraisal of different levels of insulation, heating systems, fuels, controls should be undertaken to show optimum levels of investment according to the client’s own criteria, which may be based on a simple payback period, or a specified discount rate over a given lifetime Public sector procurement policies may specifically require life cycle costing Interaction with building design, building fabric, services and facilities Occupancy When the building is to be occupied and what activities are to be carried out within it are key determinants of the heating system specification Are the occupants sedentary or physically active? What heat gains are expected to arise from processes and occupancy, including associated equipment such as computers and office machinery? Do all areas of the building have similar requirements or are there areas with special requirements? These factors may determine or at least constrain the options available The anticipated occupancy patterns may also influence the heating design at a later stage Consideration should also be given to flexibility and adaptability of systems, taking account of possible re-allocation of floor space in the future 1.2.7 Energy efficiency The term ‘energy efficiency’ gained currency during the 1980s and is now widely used In general, the energy efficiency of a building can only be assessed in relative terms, either based on the previous performance of the same building or by comparison with other buildings Thus the energy use of a building might be expressed in terms of annual energy use per square metre of floor area, and compared with benchmark levels for similar buildings The result so obtained would depend on many physical factors including insulation, boiler efficiency, temperature, control systems, and the luminous efficacy of the lighting installations, but it would also depend on the way the occupants interacted with the building, particularly if it were naturally ventilated with openable windows 1-4 Heating Note: This selection chart is intended to give initial guidance only; it is not intended to replace more rigorous option appraisal Figure 1.2 Selection chart: heating systems (17) (reproduced from EEBPP Good Practice Guide GPG303 by permission of the Energy Efficiency Best Practice Programme) Start here N Y Constraints on combustion appliances in workplace? Considering CHP, waste fuel or local community heating system available as source of heat? N Y Most areas have similar heating requirements in terms of times and temperatures? N Y Decentralised system Centralised system N Y N Y Significant spot heating (>50% of heated space)? N Y Above average ventilation rates? N Y Non-sedentary workforce? Radiant heat acceptable to process? N Y N Y N Y N Y Convective system N Y Medium or high temperature radiant system Decentralised system Convective system Low temperature radiant system Centralised system Figure 1.3 Selection chart: fuel (17) (reproduced from EEBPP Good Practice Guide GPG303 by permission of the Energy Efficiency Best Practice Programme) N Y Waste fuel or local community heating available as source of heat? N Y Strategic need for back-up fuel supply? N Y N Y N Y N Y Natural gas required? Radiant heat required? N Y Oil or LPG Electricity for high temperature systems, LPG for medium temperature systems Natural gas Oil + LPG electricity back-up Natural gas + oil back-up Community or waste heat The energy consumption of buildings is most readily measured in terms of ‘delivered’ energy, which may be read directly from meters or from records of fuels bought in bulk Delivered energy fails to distinguish between electricity and fuel which has yet to be converted to heat ‘Primary’ energy includes the overheads associated with production of fuels and with the generation and distribution of electricity Comparisons of energy efficiency are therefore sometimes made on the basis of primary energy or on the emissions of ‘greenhouse’ gases, which also takes account of energy overheads Fuel cost may also be used and has the advantage of being both more transparent and more relevant to nontechnical building owners and occupants In any event, it is meaningless to quote energy use in delivered energy obtained by adding electricity use to fuel use Consequently, if comparisons are to be made in terms of delivered energy, electricity and fuel use must be quoted separately Clearly, the performance of the heating system has a major influence on energy efficiency, particularly in an existing building with relatively poor insulation The designer has the opportunity to influence it through adopting an appropriate design strategy and choice of fuel, by specifying components with good energy performance, and by devising a control system that can accurately match output with occupant needs Particular aspects of energy efficiency are dealt with in other sections of this Guide as they arise The energy efficiency of heating and hot water systems is dealt with in detail in section of CIBSE Guide F: Energy efficiency in buildings(17) Community or waste with oil or LPG back-up 1.2.8 Community or waste with gas back-up Making the strategic decisions Each case must be considered on its own merits and rigorous option appraisal based on economic and environmental considerations should be undertaken However, the flow charts shown in Figures 1.2 and 1.3 are offered as general guidance They first appeared in Good Practice Guide GPG303(18), which was published under the government’s Energy Efficiency Best Practice programme and was aimed specifically at industrial buildings, but they are considered to be generally applicable Figure 1.2 refers to heating systems in general and Figure 1.3 to choice of fuel 1.3 Design criteria 1.3.1 General After taking the principal strategic decisions on which type of system to install, it is necessary to establish design criteria for the system in detail Typically this starts by defining the indoor and outdoor climate requirements and the air change rates required to maintain satisfactory air quality A heat balance calculation may then be used to determine the output required from the heating system under design condition, which in turn defines the heat output required in each room or zone of the building This calculation may be Design criteria 1-5 done on a steady-state or dynamic basis As the latter type of calculation can lead to extreme complexity, simplified methods have been devised to deal with dynamic effects, such as those described in CIBSE Guide A(19), section 5.6 Dynamic simulation methods using computers are necessary when dynamic responses need to be modelled in detail In all cases, however, underlying principles are the same — the required output from the heating system is calculated from consideration of the outflow of heat under design conditions, whether static or dynamic 1.3.2 Internal climate requirements Indoor climate may be defined in terms of temperature, humidity and air movement The heat balance of the human body is discussed in CIBSE Guide A, section 1.4 The human body exchanges heat with its surroundings through radiation and convection in about equal measure Thus the perception of thermal comfort depends on the temperature of both the surrounding air and room surfaces It also depends upon humidity and air movement When defining temperature for heating under typical occupancy conditions, the generally accepted measure is the dry resultant temperature, given by: tc = {tai√(10 v)+ tr}/{1+√(10 v)} (1.1) where tc is the dry resultant temperature (°C), tai is the inside air temperature (°C), tr is the mean radiant temperature (°C) and v is the mean air speed (m·s–1) For v < 0.1 m·s–1: tc = (0.5 tai + 0.5 tr ) (1.2) As indoor air velocities are typically less than 0.1 m·s–1, equation 1.2 generally applies Table 1.1 gives recommended winter dry resultant temperatures for a range of building types and activities These are taken from CIBSE Guide A(19), section 1, and assume typical activity and clothing levels Clients should be consulted to establish whether there any special requirements, such as non-typical levels of activity or clothing Guide A, section 1, includes methods for adjusting the dry resultant temperature to take account of such requirements For buildings with moderate to good levels of insulation, which includes those constructed since insulation requirements were raised in the 1980s, the difference between air and mean radiant temperature is often small enough to be insignificant for the building as a whole Nevertheless, it is important to identify situations where these temperatures differ appreciably since this may affect the output required from heating appliances As a general rule, this difference is likely to be significant when spaces are heated non-uniformly or intermittently For some appliances, e.g fan heater units, the heat output depends only on the difference between air temperature and heating medium temperature For other types of appliance, e.g radiant panels, the emission is affected by the temperature of surrounding surfaces Section 1.3.3.3 below deals with this subject in greater detail Temperature differences within the heated space may also affect the perception of thermal comfort Vertical temperature differences are likely to arise from the buoyancy of warm air generated by convective heating In general it is recommended that the vertical temperature difference should be no more than K between head and feet If air velocities are higher at floor level than across the upper part of the body, the gradient should be no more than K·m–1 Warm and cold floors may also cause discomfort to the feet In general it is recommended that floor temperatures are maintained between 19 and 26 °C, but that may be increased to 29 °C for under-floor heating systems Asymmetric thermal radiation is a potential cause of thermal discomfort It typically arises from: — proximity to cold surfaces, such as windows — proximity to hot surfaces, such as heat emitters, light sources and overhead radiant heaters — exposure to solar radiation through windows CIBSE Guide A recommends that radiant temperature asymmetry should result in no more than 5% dissatisfaction, which corresponds approximately to vertical radiant asymmetry (for a warm ceiling) of less than K and horizontal asymmetry (for a cool wall) of less than 10 K The value for a cool ceiling is 14 K and for a warm wall is 23 K It also gives recommended minimum comfortable distances from the centre of single glazed windows of different sizes In buildings that are heated but not have full air conditioning, control of relative humidity is possible but unusual unless there is a specific process requirement Even where humidity is not controlled, it is important to take account of the range of relative humidity that is likely to be encountered in the building, particularly in relation to surface temperatures and the possibility that condensation could occur under certain conditions Also, account should be taken of air movement, which can have a significant effect on the perception of comfort Where the ventilation system is being designed simultaneously, good liaison between the respective design teams is essential to ensure that localised areas of discomfort are avoided through appropriate location of ventilation outlets and heat emitters, see section 2: Ventilation and air conditioning For a building with an existing mechanical ventilation system, heating system design should also take account of the location of ventilation supply outlets and the air movements they produce The level of control achieved by the heating system directly affects occupant satisfaction with the indoor environment, see CIBSE Guide A, section 1.4.3.5 Although other factors also contribute to satisfaction (or dissatisfaction), the ability of the heating system and its controls to maintain dry resultant temperature close to design conditions is a necessary condition for satisfaction Further guidance on comfort in naturally ventilated buildings may be found in CIBSE Applications Manual AM10: Natural ventilation in non-domestic buildings (20) The effect of temperatures on office worker performance is addressed in CIBSE TM24: Environmental factors affecting office worker performance (21) Close control of temperature is often impractical in industrial and warehouse buildings, in which temperature variations of ±3 K may be acceptable Also, in such buildings the requirements of processes for temperature control may take precedence over human comfort 1-6 Heating Table 1.1 Recommended winter dry resultant temperatures for various buildings and activities(19) Building/room type Temperature / °C Airport terminals — baggage reclaim — check–in areas — customs areas — departure lounges 12–19 18–20 12–19 19–21 Banks, building societies and post offices — counters — public areas Building/room type Temperature / °C Hotels — bathrooms — bedrooms 26–27 19–21 Ice rinks 12 19–21 19–21 Laundries — commercial — launderettes 16–19 16–18 Bars, lounges 20–22 Law courts 19–21 Churches 19–21 Computer rooms 19–21 Conference/board rooms 22–23 Libraries — lending/reference rooms — reading rooms — store rooms 19–21 22–23 15 Drawing offices 19–21 Dwellings — bathrooms — bedrooms — hall/stairs/landing — kitchen — living rooms — toilets 26–27 17–19 19–24 17–19 20–23 19–21 Museums and art galleries — display — storage 19–21 19–21 Offices — executive — general — open plan 21–23 21–23 21–23 Educational buildings — lecture halls — seminar rooms — teaching spaces 19 –21 19–21 19–21 Exhibition halls 19–21 Public assembly buildings — auditoria — changing/dressing rooms — circulation spaces — foyers 22–23 23–24 13–20 13–20 Factories — heavy work — light work — sedentary work Prison cells 19 –21 11–14 16–19 19–21 Fire/ambulance stations — recreation rooms — watch room 20–22 22–23 Railway/coach stations — concourse (no seats) — ticket office — waiting room 12–19 18–20 21–22 Restaurants/dining rooms 22–24 Garages — servicing 16–19 General building areas — corridors — entrance halls — kitchens (commercial) — toilets — waiting areas/rooms 19–21 19–21 15–18 19–21 19–21 Retail buildings — shopping malls — small shops, department stores — supermarkets 19–24 19–21 19–21 Sports halls — changing rooms — hall 22–24 13–16 Squash courts 10–12 Swimming pools — changing rooms — pool halls 23–24 23–26 Television studios 19–21 Hospitals and health care — bedheads/wards — circulation spaces (wards) — consulting/treatment rooms — nurses stations — operating theatres 22–24 19–24 22–24 19–22 17–19 1.3.3 Design room and building heat loss calculation 1.3.3.1 Calculation principles The first task is to estimate how much heat the system must provide to maintain the space at the required indoor temperature under the design external temperature conditions Calculations are undertaken for each room or zone to allow the design heat loads to be assessed and for the individual heat emitters to be sized 1.3.3.2 External design conditions The external design temperature depends upon geographical location, height above sea level, exposure and thermal inertia of the building The method recommended in Guide A is based on the thermal response characteristics of buildings and the risk that design temperatures are exceeded The degree of risk may be decided between designer and client, taking account of the consequences for the building, its occupants and its contents when design conditions are exceeded Index Terms Links Temperatures (Cont.) horticultural facilities 2–50 induction units 2–98 liquid fuel storage 1–57 modelling 2–99 2–140 multi-zoned systems 2–75 multi-purpose sports facilities 2–44 museums, libraries and art galleries 2–41 office buildings 2–56 refrigeration and heat rejection design 4–5 retail buildings 2–43 swimming pools 2–44 thermoacoustic refrigeration 4–40 through-the-wall units 4–45 toilets 4–19 4–26 2–45 1–6 variable air volume systems 2–102 vortex tube cooling 4–41 water storage 2–41 — see also Climate; Comfort; Dry resultant temperatures; Environmental temperature; Floor temperatures; Ground temperatures; Heat gains; Heat losses; Radiant temperature asymmetry; Temperature control; Temperature differences; Water temperatures Terminal reheat systems Terminals air velocities airflow measurement cleanliness 2–101 to 102 2–103 2–50 2–51 to 56 2–132 to 133 3–10 3–51 3–52 2–133 3–10 3–38 to 39 2–34 dampers 3–34 to 35 3–40 displacement ventilation 2–57 documentation 3–40 health care premises 2–34 high pressure ductwork 3–28 3–30 noise and noise control 3–4 3–30 3–35 5–8 5–15 to 19 5–40 to 41 partially centralised air/water systems 2–72 pressure drops 3–30 refrigeration 4–5 This page has been reformatted by Knovel to provide easier navigation 3–31 Index Terms Links Terminals (Cont.) split systems 2–105 variable air volume systems 2–102 to 105 — see also Air inlets; Air outlets; Airport terminals; Bus terminals; Diffusers; Extract ventilation; Grilles; Jets; Louvres Test holes 3–20 3–34 3–41 3–42 3–6 to 3–18 to 19 3–39 4–5 3–40 Testing air leakage batteries 2–124 cooling towers 4–51 ductwork filters TEWI 3–38 3–6 to 3–8 3–18 to 19 3–38 to 41 3–45 3–51 2–119 to 121 fire dampers 3–20 natural ventilation 2–65 (total equivalent warming impact) 4–14 3–21 4–15 4–30 3–34 3–36 3–37 1–11 1–25 2–78 1–10 to 11 1–24 to 26 2–5 2–6 2–62 2–76 to 80 2–140 4–37 Textile ducting Theatres — see Assembly halls and auditoria; Health care premises Thermal admittance Thermal bridges 1–7 to Thermal capacity chimneys 1–51 education buildings 2–43 heat recovery 2–64 heating 1–7 2–77 ventilation and air conditioning — see also Exposed thermal mass; Passive cooling Thermal comfort — see Comfort Thermal convection coefficients 2–23 Thermal gradients — see Temperature differences Thermal inertia — see Thermal capacity This page has been reformatted by Knovel to provide easier navigation Index Terms Links Thermal insulation 1–12 to 13 airtightness and 4–15 4–16 3–36 chimneys 1–51 to 52 computer rooms 2–26 condensation 2–18 cooled surfaces 2–83 costs and costing 2–61 1–3 domestic buildings 2–28 ductwork 2–28 2–67 3–5 3–14 to 16 3–23 3–35 3–37 ductwork access 3–19 ductwork supports 3–24 fibrous duct linings 5–14 flexible ducting 3–34 inspection 3–45 openings 3–19 passive stack ventilation 2–28 3–35 3–5 3–23 space requirements storage vessels 1–18 student accommodation 2–43 temperature drop calculation 3–65 thicknesses 3–15 to 16 underfloor heating ventilation strategy selection weight 3–65 1–17 2–6 3–37 — see also U-values Thermal mass — see Thermal capacity Thermal resistance 1–8 1–12 1–7 1–13 1–25 1–18 2–77 to 78 2–79 2–85 2–140 4–37 1–14 2–85 2–86 2–117 to 118 4–37 — see also U-values Thermal response Thermal storage — see also Building fabric; ‘Coolth’; Night cooling; Thermal capacity Thermal wheels Thermionic refrigeration Thermoacoustic refrigeration 4–40 4–40 to 41 Thermodynamic steam traps 1–40 Thermoelectric cooling 4–38 Thermostatic expansion valves 4–37 This page has been reformatted by Knovel to provide easier navigation 1–42 4–42 4–44 Index Terms Links Thermostatic radiator valves 1–18 1–37 Thermostatic steam traps 1–40 1–41 Thermostats 1–18 1–19 1–23 1–37 1–45 2–50 4–22 to 23 4–24 4–43 5–10 5–11 3–38 — see also Sensors Thermosyphon chillers Thicknesses duct linings ductwork 3–36 to 37 ductwork insulation 3–15 to 16 Threshold of hearing 3–65 5–36 Through-wall air conditioners — see Room air conditioners Throw 1–44 2–51 to 52 2–54 2–103 2–105 3–35 2–15 2–17 2–24 2–26 2–28 2–36 4–45 Tobacco smoke 2–119 Toilets air infiltration allowances 1–10 commercial buildings 1–18 domestic buildings 2–30 2–46 extract ventilation 2–45 2–46 health care premises 2–35 mechanical ventilation 2–42 mixed mode ventilation 2–70 sports facilities 2–45 temperatures 1–6 ventilation 1–9 2–13 2–46 4–14 4–15 4–30 Total equivalent warming impact (TEWI) 4–37 Total pressure 3–3 3–29 3–26 3–28 — see also Fan total pressure Total pressure loss 3–29 3–30 — see also Static regain method Total radiant heating 1–23 1–24 Training 2–28 2–42 4–9 4–17 — see also Weight training facilities This page has been reformatted by Knovel to provide easier navigation 2–71 Index Terms Links Transfer grilles 2–30 2–112 Transmissibility 5–24 5–25 Transportation buildings 2–13 2–46 to 47 Trapeze supports 5–33 Transmission — see Noise transmission Triangular ducting 3–4 to Trickle ventilators 2–110 to 111 communal residential buildings 2–26 domestic buildings 2–28 2–29 draught minimisation 2–62 2–108 education buildings 2–42 heat gains and 3–36 2–9 high-rise buildings 2–30 passive stack ventilation 2–43 student accommodation 2–43 Tunnels 3–36 2–46 — see also Wind tunnels Turndown 2–55 2–102 2–103 Turning vanes 2–67 3–8 3–11 to 12 3–22 5–11 Twin-wall ducting — see Double skin ducting Two-phase secondary coolants 4–36 Two-pipe hydronic systems 1–15 Two-stage evaporative cooling 2–89 U U-ducts 1–51 U-values 1–7 to 3–14 — see also Thermal insulation Ultra-low particle arrestor (ULPA) filters 2–120 Ultrasonic humidifiers 2–124 Ultraviolet germicidal irradiation (UVGI) 2–121 2–127 2–128 Ultraviolet lamps 3–44 Underfeed stokers 1–33 Underfloor cooling 2–94 Underfloor heating 1–5 1–13 1–15 1–17 1–30 to 31 2–45 Underfloor ventilation 2–18 2–28 2–60 Underground railway stations 2–47 Uninterruptible power supplies 4–7 Unlined straight ducts 5–9 — see also Floor temperatures This page has been reformatted by Knovel to provide easier navigation Index Terms Links US FS 209E Users 2–24 2–25 4–3 to 4–5 4–8 4–9 4–11 4–17 — see also Comfort; Occupant control; Occupant training UVGI (ultraviolet germicidal irradiation) 2–121 V Valves 1–38 to 39 chilled beams and ceilings 2–81 hydronic heating 1–15 noise and noise control refrigeration systems steam heating 1–18 to 19 5–5 4–29 4–31 4–37 1–20 to 21 1–22 1–40 — see also Expansion valves; Float valve regulators; Pressure reducing sets; Radiator valves; Regulating valves Vapour, as refrigerant 4–27 Vapour barriers 2–18 2–26 3–14 to 15 3–16 to 17 3–24 3–51 4–12 4–31 to 32 4–36 4–46 to 47 4–4 4–7 Vapour compression chillers Vapour compression refrigeration 4–18 4–10 4–23 to 32 — see also Heat pumps Vapour generators 2–125 Vapour sealing — see Vapour barriers Vapours Variable air volume (VAV) systems air conditioning 2–120 2–121 2–72 2–102 to 105 1–44 airflow 2–105 5–5 broadcasting studios 2–22 commissioning 3–39 dealing rooms 2–49 dual duct systems 2–86 2–87 to 88 3–7 3–28 3–40 2–102 2–103 ductwork 5–5 energy efficiency 2–34 3–7 fans 2–103 health care premises 2–34 heating 1–44 This page has been reformatted by Knovel to provide easier navigation 3–40 2–103 Index Terms Links Variable air volume (VAV) systems (Cont.) hotels 2–36 laboratories 2–39 noise 5–3 pressure control 5–5 3–40 Variable flow systems 3–7 4–22 4–48 to 49 4–45 4–53 Variable orifice double regulating valves 1–39 Variable refrigerant flow (VRF) systems 2–35 2–73 Variable speed compressors 4–52 4–53 3–7 4–7 4–15 2–68 Variable speed drives Variable speed fans cleanrooms 2–25 cooling towers 4–50 energy efficiency 1–13 2–46 3–7 4–7 safety cabinets 2–40 Variable speed pumping 1–13 1–18 to 19 4–7 4–48 Vehicle exhaust gases 1–36 to 37 2–46 to 47 Velocities noise and vibration control 5–23 5–25 5–35 3–28 3–30 5–46 steam heating systems 1–20 — see also Air velocities; Efflux velocities; Face velocities; Water flow rate Velocity method 3–28 Velocity pressure 3–3 Velocity reset VAV boxes Vent pipes 2–105 1–19 — see also Ventilation stacks Ventilated air spaces 2–18 Ventilated ceilings 2–23 Ventilated chimneys 1–52 2–27 Ventilated luminaires — see Air handling luminaires Ventilation and air conditioning 2–1 to 142 basements 3–22 heat losses 1–8 to 10 1–23 1–25 2–64 1–5 1–7 1–23 1–45 heating systems This page has been reformatted by Knovel to provide easier navigation 1–24 1–9 Index Terms Links Ventilation and air conditioning (Cont.) steam systems 1–21 1–41 — see also Air conditioning; Displacement ventilation; Exhaust ventilation; Extract ventilation; Mechanical ventilation; Natural ventilation Ventilation and air conditioning control air control units 2–4 2–132 assembly halls and auditoria assessment of requirements 2–19 2–140 to 141 broadcasting sudios 2–22 chilled beams and ceilings 2–81 comfort cooling and air conditioning 2–73 to 75 communal residential buildings 2–26 computer rooms 2–27 cooled surfaces 2–83 cooling 2–73 to 75 displacement ventilation 2–57 domestic buildings 2–29 evaporative cooling 2–89 extract fans 2–29 fan coil units 2–91 heat pumps 2–97 hotels 2–35 industrial buildings 2–32 mechanical ventilation mixed mode ventilation natural ventilation 2–9 to 10 2–32 2–68 2–110 to 111 2–112 to 113 2–64 2–68 2–71 2–63 to 64 night cooling 2–79 partially centralised air/water services 2–73 room air conditioners 2–99 sensors 2–63 2–112 to 113 single zone air conditioning split unit local air conditioning swimming pools variable air volume systems windows 2–100 to 101 2–105 2–45 2–105 2–107 to 108 — see also Sensors Ventilation capacity windows 2–107 — see also Air supply This page has been reformatted by Knovel to provide easier navigation 2–108 Index Terms Links Ventilation efficiency — see Performance Ventilation heat losses Ventilation heat recovery 1–8 to 10 1–23 1–25 2–64 1–14 2–34 1–24 2–43 2–46 Ventilation loads 1–9 Ventilation rates 2–13 to 16 air leakage and 2–28 ancillary halls 2–44 animal husbandry facilities 2–48 assembly halls and auditoria 2–19 bathrooms 2–140 2–45 1–9 bus terminals 2–47 car parks 2–46 cleanrooms 2–25 comfort 2–53 communal residential buildings 2–26 cooling and 2–5 darkrooms 2–49 diffusers 2–53 domestic buildings 1–9 2–13 2–28 1–8 to 2–5 2–30 to 31 2–32 2–36 1–9 2–23 2–30 ductwork sizing estimation 3–6 education buildings 2–42 food processing facilities 2–13 grilles 2–53 health care premises 2–35 heating design 1–4 horticultural facilities 2–50 hotels 2–36 industrial buildings kitchens laboratories 2–39 mechanical ventilation 2–9 museums, libraries and art galleries 2–40 natural ventilation 2–63 night cooling 2–78 retail buildings 2–43 single sided ventilation 2–59 sports facilities 2–44 terminals 2–53 toilets 1–9 This page has been reformatted by Knovel to provide easier navigation 2–44 2–45 2–46 Index Terms Links Ventilation rates (Cont.) variable air volume systems whole-house mechanical ventilation 2–102 2–30 — see also Airflow rates Ventilation stacks 1–19 2–107 2–115 2–1 to 2–3 to 2–5 2–6 2–7 to 12 4–5 to 2–22 2–140 1–21 1–41 1–42 Vertical ducts 3–5 3–6 3–24 Vertical risers 3–5 3–10 3–30 to 31 1–5 2–56 2–57 5–5 to 5–22 to 33 5–34 3–10 5–9 5–27 5–28 to 29 5–33 5–34 4–12 5–4 5–5 5–6 5–25 4–29 — see also Roof ventilators Ventilation strategies air distribution 2–50 to 57 assembly halls and auditoria 2–18 to 19 atria 2–20 to 21 broadcasting studios 2–22 clean rooms 2–25 communal residential buildings 2–26 computer rooms 2–27 cooling 2–10 4–5 to domestic buildings 2–28 to 30 fire protection 2–64 to 65 health care premises 2–33 to 34 hotels 2–35 to 36 industrial buildings 2–32 laboratories 2–38 to 40 natural ventilation 2–57 to 62 retail premises 2–43 to 44 Ventilators — see Automatic ventilators; Heat recovery; Humidity-sensitive vents; Roof ventilators; Room ventilators; Trickle ventilators; Vent pipes; Ventilation stacks Venting, steam systems 3–51 Vertical temperature differences Vibration and vibration control 5–46 to 47 ductwork noise and This page has been reformatted by Knovel to provide easier navigation Index Terms Links Vibration and vibration control (Cont.) plant rooms 5–7 5–22 5–30 5–33 refrigeration and heat rejection 4–11 4–12 — see also Structure-borne noise Vibration criteria 5–25 to 26 Vibration data 5–24 to 25 Vibration isolation efficiency (VIE) Vibration isolators 5–24 5–25 5–26 5–28 5–32 3–43 4–12 5–6 5–7 5–22 5–24 5–26 to 33 Vibration limits 5–25 to 26 Vibration measurement 5–23 to 24 5–46 to 47 Visual impact — see Aesthetics Voices, sound power 5–18 to 19 Volatile organic compounds (VOCs) 2–15 to 16 2–42 2–129 2–132 3–40 2–35 2–73 4–45 2–18 2–114 5–4 5–7 5–14 5–17 to 18 1–5 1–10 1–22 2–30 to 32 3–34 1–12 1–22 to 23 2–30 2–45 1–54 1–55 Volume control — see also Air supply Vortex tube cooling VRF 4–41 (variable refrigerant flow) systems W Walls 5–33 — see also Openings Warehouses — see also Commercial buildings; Industrial buildings Warm air systems 1–43 to 45 Warm floors — see Floor temperatures; Underfloor heating Waste, as fuel Waste disposal ductwork cleaning refrigeration 3–45 4–4 4–12 4–14 4–26 4–29 4–30 4–35 — see also Pollution This page has been reformatted by Knovel to provide easier navigation Index Terms Links Waste heat — see Heat recovery Water, as secondary coolant 4–36 Water atomising humidifiers 2–125 Water-based distribution 2–70 Water chillers — see Chillers Water cooled condensers 4–43 4–49 Water cooling 2–81 2–82 2–94 to 96 2–106 4–20 to 21 4–43 Water density values 1–26 Water expansion — see Expansion Water flow rates chilled water systems 4–53 combination boilers 1–16 1–18 heat emissions and 1–27 1–62 to 63 humidifiers 2–127 hydronic heating sea/river/lake water cooling 1–15 1–18 1–36 1–62 to 63 1–27 2–106 steam systems 1–20 system balancing 1–16 1–22 — see also Variable flow systems Water flow sensors 1–37 Water hammer 1–21 Water heaters 1–16 1–22 1–41 4–32 4–34 Water heating — see Hot water services; Hydronic heating systems Water injection humidification 2–142 Water leakage 3–44 Water/lithium bromide systems 4–14 4–35 Water Regulations Water source heat pumps 2–41 2–128 1–34 to 35 2–35 2–43 2–41 2–127 4–23 Water storage 1–18 4–50 — see also Water treatment Water supply 2–128 4–50 Water temperatures boiler corrosion 1–52 boiler selection 1–33 chilled beams and ceilings condensers 2–80 to 81 4–53 This page has been reformatted by Knovel to provide easier navigation 2–82 4–5 Index Terms Links Water temperatures (Cont.) cooled surfaces 2–82 evaporators 4–42 heat emissions and 1–27 Legionella bacteria 2–128 pressure drops and 1–36 sea/river/lake water cooling 2–106 swimming pools 2–45 underfloor heating 1–17 variable air volume systems 2–83 2–103 — see also Chilled water systems Water treatment cooling towers 4–9 4–14 4–22 4–50 costs and costing 4–7 4–50 evaporative condensers 4–7 4–9 4–14 4–18 4–22 4–43 2–89 4–7 4–9 2–127 2–128 4–18 4–4 4–7 4–9 4–14 4–18 evaporative cooling humidifiers refrigeration and heat rejection steam systems 4–18 1–41 waste disposal and environmental issues wet and dry coolers 4–4 4–14 4–49 — see also Corrosion; Legionella bacteria Water tube boilers 1–39 1–50 Water vapour — see Condensate removal; Condensation; Moisture control; Vapour Wavelengths 5–35 Weather data 1–7 2–140 2–106 2–123 Weather protection 3–45 Weight, ductwork 3–8 3–36 to 37 Weight training facilities 2–44 2–45 Weighted sound reduction index 5–18 Weighting networks 5–45 Welded steel and reverse flow boilers 1–31 Welfare of Farm Animals (England) Regulations 2–48 Wet and dry coolers 4–49 Wetted media humidifiers 2–125 This page has been reformatted by Knovel to provide easier navigation 3–38 Index Terms Links Whole building calculation method 4–16 Whole life costs — see Life cycle costs and costing Whole-house ventilation 2–26 2–28 Wind driven ventilation 2–8 2–57 to 58 2–30 — see also Cross ventilation Wind power 1–54 to 55 Wind pressures 2–30 2–33 2–60 2–61 2–65 2–107 2–111 2–111 Wind scoops 2–58 2–60 Wind sensors 2–64 2–112 Wind tunnels 2–39 2–141 Window mounted refrigeration units 4–45 Window units — see Room air conditioners Windows air infiltration comfortable distances education buildings heat loss calculations 2–6 2–11 2–112 4–5 2–63 2–107 1–5 2–42 1–8 heater location 1–12 noise and noise control 2–63 U-values 5–4 1–8 underfloor heating and 1–17 — see also Glazing; Lighting; Mixed mode ventilation; Natural ventilation Wobbe number 1–53 Wood, as fuel 1–54 Work efficiency 5–20 Working pressure — see Pressures Workplace Directive 3–42 Workplace (Health, Safety and Welfare) Regulations 1992 3–42 Y Y-value — see Thermal admittance Z Zoned air handling units 2–33 to 34 This page has been reformatted by Knovel to provide easier navigation 2–88 2–107 to 110 2–108 Index Terms Links Zones and zoning air conditioning 2–36 2–74 2–75 to 76 2–86 2–100 to 101 2–132 3–6 airport terminals 2–47 broadcasting studios 2–22 cooled surfaces 2–83 cooling dual duct systems ductwork 2–75 to 76 3–6 2–86 2–87 3–6 fan coil units 2–91 heat losses 1–8 heating 1–14 1–15 1–18 1–23 high-rise buildings 2–33 hot deck/cold deck systems 2–86 hotels 2–36 induction units 2–99 mechanical ventilation 2–68 mixed mode ventilation 2–10 to 11 2–71 radiant heating 1–23 single duct systems 2–100 variable air volume systems 2–103 — see also Multi-zoned systems; Nearzones; Occupied zones; Perimeter zones This page has been reformatted by Knovel to provide easier navigation 1–17 2–88 2–69 2–70 ... covered by BS ISO 15686 1-1 (4 8) and guidance is given by HM Treasury (4 9), the Construction Client’s Forum (1 ), BRE (5 0) and the Royal Institution of Chartered Surveyors (5 1) See also CIBSE? ??s Guide. .. outputs between 100 kW and MW Boilers of this type are covered by BS 85 5(8 4) (d) Steel shell and fire-tube boilers Steel shell and fire-tube boilers consist of a steel shell and a furnace tube connected... valve types: (a) plug and seat three-port mixing valve, single seat; (b) plug and seat three-port mixing valve, double seat; (c) two-part plug and seat valve; (d) rotary shoe valve; (e) butterfly