ISO/TR TECHNICAL REPORT 16494-2 First edition 2019-03 Heat recovery ventilators and energy recovery ventilators Method of test for performance - Part 2: Assessment of measurement uncertainty of performance parameters Reference number ISO/TR16494-2:2019(E) ISO @IS02019 IS0/TR 16494-2:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ISO2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below orIso's memberbody in the countryof therequester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone:+41227490111 Fax:+4122749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0/TR16494-2:2019(E) Contents Page Foreword ..iv Introduction.. ... 1 Scope. 2 Normative references 3 Terms and definitions 4 Symbols ..2 5 Explanatorynotes useful in laboratory application .3 5.1 Uncertainty. .3 5.2 Confidence level ..4 5.3 Evaluationofuncertainties .4 5.4 Steps in evaluation of uncertaintyinmeasurements 5.5 Uncertainty of measurements .4 5.5.1 Uncertaintyofindividualmeasurements .4 5.5.2 Uncertainty of a mean value from several measurements 6 5.5.3 Uncertainty of a value obtained by usinga smoothing curve .7 6 Evaluation of uncertainty .7 6.1 Airflow performance 7 6.1.1 Airvolumeflow rate .7 6.1.2 Airmass flowrate 6.1.3 Staticpressuredifferential .8 6.2 Unitexhaustairtransferratio .9 6.2.1 Measured parameters affecting test results 9 6.2.2 UEATR measurement. .9 6.2.3 Uncertainty calculation General case .9 6.3 Net supply airflow. .9 6.3.1 Net supply airflow ducted units. 9 6.3.2 Net supply airflow unducted ventilators .10 6.4 Grosseffectiveness. .11 6.4.1 Measured parameters affecting the measurement .11 6.4.2 Gross effectivenessmeasurement. ..11 6.4.3 Uncertainty calculation-General case .12 6.5 Coefficient of energy .12 6.5.1 Coefficient of energy: Ducted ventilators ..12 6.5.2 Coefficient ofenergy-Unducted ventilators 6.6 Effective work (EW) ..16 6.6.1 Measured parameters affecting the measurement ..16 6.6.2 Effective work: Ducted or unducted ventilators. ..16 6.6.3 Uncertainty calculation Generalcase ..16 6.6.4 Uncertainty calculation-Specific case. ..16 AnnexA (informative)Uncertaintybudget sheets. ..17 Annex B (informative) Determination of indirect contribution to uncertainty, U(C) ..42 Bibliography .43 IS0 2019 - All rights reserved iii