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Air Infiltration Calculation Techniques an Applications Guide

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Air Infiltration Calculation Techniques an Applications Guide INTERNATIONAL ENERGY AGENCY energy conservation in buildings and community systems programme Air Infiltration Calculation Techniques An Applications Guide University of Warwick Science Park SQvereign Court Sir William Lyons Ro~d Cavsntw CV4 7EZ Gmat Britain This report is part of the work U, we IEA Energy Conservetion in Buildings & Community Systems Programme. Annsx V Air Infiltration end Ventilation Centre This rsport is publlshed by! The Air Infiltration and Venrilafion Centre University of Warwick Science Park Unit 3A, Sovereign Court Sir Williarn Lyons Road Coventry CV4 7EZ Great Britain Telephone: +44 (0) 1203 892050 Telephone: a44 (0)24 766Q 2060 with effect from 1/6/99 * Fax: +44 (0) 1203 416306 Fax: t44 (0) 24 7641 6306 with effed from 1/8/99 * Emall: [email protected]~ web: http:/hnnnnnr.aivo.org/ Head of Centre: Manln W. Liddament, BA, PhD. MASHRAE. *From 1st June 1900 untll 18th August 2000 the old and the new numbers will run in parsllel. Air Infiltration Calculation Techniques - An Applications Guide Martin W. Liddament June 1986 @Copyright Oscar Faber Partnership 1986. All property rights, including copyright are vested in the Operating Agent (Oscar Faber Consulting Engineers) on behalf of the International Energy Agency. In particular, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the Operating Agent. This report is part of the work of the IEA Energy Conservation in Buildings & Community Systems Programme. Annex V Air Infiltration and Ventilation Centre Document AIC-AG-1-86 Distribution: Annex Participants only ISBN 0 946075 25 5 Additional copies of this report may be Participants inthis task: obtained from: Belgium, Canada, Denmark, Federal Republic of The Air Infiltration and Ventilation Centre, Germany, Finland, Netherlands, New Zealand, Old Bracknell Lane West, Norway, Sweden, Switzerland, United Kingdom Bracknell, Berkshire and United States of America. RG12 4AH, Great Britain. CONTENTS Prefaoe How to Uee thia Guide Introduotion CHAPTER 11 Soope of Applicatione and Teohnlauen INTRODUCTION 1.3 1 .l VENTILATION NEEDS AND STRATEGIES 1 .l .l Industrial Buildings 1 .l .2 Commercial Buildings 1 .l .3 Dwellings 1.2 VENTILATION OPTIONS 1.6 1.2.1 Natural Ventilation 1.6 1 .2.2 Mechanical Extract (or Supply) Ventilation 1.7 1 -2.3 Balanced Supply/Ektract Syeteme 1.8 1.3 TOWARDS AIR INFILTRATION MODELLING 1.9 1.3.1 Air Infiltration Charaoteristics 1.9 1.3.2 Seasonal and Climatic Variations in Air Infiltration Rates 1 .l0 1.3.3 Terrain and Shielding Effeots on Air Infiltration 1.11 1.3.4 Distribution and Size of Openings 1.11 1.3.5 Purpose-Provided Ventilation 1 .l2 1.4 NUMERICAL METHODS 1.4.1 Calculation Techniques 1.4.2 Hierarchical Order of Techniquee 1 .4.3 Single/Multi-Zone Selection 1.4.4 Selecting a Calaulation Technique References 1.20 CHAPTER 2: Empirical Teahniques INTRODUCTION 2.1 mIRICAL MODELS 2.1 .l Air rbange Methods 2.1.2 Redk.lon of Pressurization Test Data 2.1.3 Regression Techniques References CHAPTER 31 Theoretioal Methods INTRODUCTION 3.1 THEORETICAL BACKGROUND 3.1 .l Flow Mechanisms 3.1.2 Ventilation Mfioiency 3.1 .3 Driving Forces 3.1.3.1 Wind Induoed Pressure Distribution 3.1.3.2 Turbulent Fluctuations 3.1.3.3 Stack Effeot 3.1.3.4 Combined Wind and Stack Effect 3.1.3.5 Pressure Effects Due to Mechanical Ventilation 3.2 THEORETICAL CALCULATION TECHNIQUES 3.2.1 Single Zone Network Models 3.2.2 Multi-Zone Network Models 3.2.3 Simplified Theoretical Teohniques 3.3 DATA REQUIREMENTS 3.3.1 Flow Network 3.3.1 .l Component Leakage Openings 3.3.1.2 'Background' or 'Fabric1 Leakage Openings 3.3.3 .3 Large Openings 3.3.1.4 Interior Flow Paths 3.3.2 Flow Characterietioe of Openings 3.3.2.1 Numerical Deeoription of Flow Characteristice 3.3.2.2 Measurement of Air Flow Characteristics 3.3.3 Climatic and Terrain Data References CHBPTER 41 Subsidiary Caloulatione INTRODUCTION 4.1 HEAT RECOVERY 4.1.1 Heat Loee Calculation 4.1.2 Heat Reoovery Calculation 4.2 COST-EFFECTIVWESS OF VENTILATION STRATEGIES 4.2.1 Conditions for Cost-Effectiveness of Ventilation Strategies 4.3 INDooR AIR QUALITY 4.3.1 Baokdraughting 4.3.2 Pollutant Concentration and Minimum Ventilation Ratee References CHAPTER 5: Algorithm and Worked ~mples 5.1 ALGORITHMS 5.1.1 Lawrence Berkeley Laboratory ELA Algorithm 5.1.2 National Bureau of Standards Model 5.1.3 National Reeearch Council of Canada Model 5.2 EXAMPLES 5.2.1 Calculation of Wind and Stack Pressure 5.2.2 Distribution of Openings 5.2.3 Induetrial Building 5.2.4 Ventilation Strategy CHAPTER 6: Data Reference 6.1 CLIMATIC DATA 6.2 WIND PRESSURE DATA 6.3 AIR LEAKAGE DATA 6.4 GLOSSARY PREFACE International Energy Agency In order to strengthen cooperation in the vital area of energy policy, an Agreement on an International Ehergy Programme was formulated among a number of industrialised countries in November 1974. The International Energy Agency (IEA) was established as an autonomous body within the Organisation for Economic Cooperation and Development ( OECD) to administer that agreement. Twenty-one countries are currently members of the IM, with the Commission of the European Communities participating under a special arrangement. As one element of the International Energy Programme, the Participants undertake cooperative activities in energy research, development, and demonstration. A number of new and improved energy technologies which have the potential of making significant contributions to our energy needs were identified for collaborative efforts. The IEA Committee on Energy Research and Development ( CRD) , assisted by a small Secretariat staff, coordinates the energy research, development, and demonstration programme. Energy Conservation in Buildings and Community Systeme The International Energy Agency sponsors research and development in a number of areas related to energy. In one of these areas, energy conservation in buildings, the IEA is sponsoring various exercises to predict more accurately the energy use of buildings, including comparison of existing computer programs, building monitoring, comparison of calculation methods, etc. The difference and similarities among these comparisons have told us much about the state of the art in building analysis and have led to further IEA sponsored research. Annex V Air Infiltration and Ventilation Centre The IEA Executive Committee (Building and Community Systems ) has highlighted areas where the level of knowledge is unsatisfactory and there was unanimous agreement that infiltration was the area about which least was known. An infiltration group was formed drawing experts from most progressive countries, their long term aim to encourage joint international research and increase the world pool of knowledge on infiltration and ventilation. Much valuable but sporadic and uncoordinated research was already taking place and after some initial groundwork the experts group recommended to their executive the formation of an Air Infiltration and Ventilation Centre. This recommendation was accepted and proposals for its establishment were invited internationally. The aims of the Centre are the standardisation of techniques, the validation of models, the catalogue and transfer of information, and the encouragement of reeearch. It is intended to be a review body for current world research, to ensure full diseemination of this research and based on a knowledge of work already done to give direction and firm basis for future research in the Participating Countries. The Participants in this taek are Belgium, Canada, Denmark, Federal Republic of Germany, Finland, Netherlands, New Zealand, Norway, Sweden, Switzerland, United Kingdom and the United States. Aohowledgemente The preparation of this guide depended on the effort and cooperation of many Individuals and organisations. In particular, Max Sherman from the Lawrence Berkeley Laboratory in the United States contributed substantially to Section 1.4 on selecting a calculation technique. Carolyn Allen, a former colleague at the Air Infiltration and Ventilation Centre, was responsible for locating much of the source information for the data reference section. Coneiderable assistance covering the analysis and presentation of air leakage data (Chapter 6, Section 3) and the preparation of the glossary of terme was contributed by Jack Peach. In addition valuable advice and assistance concerning the content of this publication wae gratefully received from all members of the AIVC Steering Croup and from all those who attended the Applicationst Guide workshop and other working meetings. The author would also like to thank Jenny Elmer of the AIVC for her assistance in proof reading this publication and for producing a print ready copy. Editing and formatting of this document was by Glen Myers and John Gardner of Pheonix Technical Publications. Illustrations were prepared by nba tectonics. Caution: The material and data presented in this publication is solely intended as a guide to current knowledge on air infiltration and related topics. The information contained herein does not supersede any advioe or requirements given in any national codes or regulatione, neither is its suitability for any particular application guaranteed. No responalbllity can be accepted for any inaccuracies resulting from the use of this publication. How To Use Thie Guide The guide has been designed so that the material you need for your intended application is easily accessible. The flow chart in Figure 1 illustrates the structure. Chapter 1 is a general introduction to the subject which outlines ventilation needs, strategies and options and then describes the essential components of air infiltration calculation techniques. Section 1.4 of Chapter 1 will help you decide which air infiltration calculation technique best suits your data needs. In general you will have to choose either an empirical measurement-based route, or a more fundamental theory-based technique.
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