UK Data Archive Study Number 8151 - Renewable Heat Premium Payment Scheme: Heat Pump Monitoring: Cleaned Data, 2013-2015 ANALYSIS OF DATA FROM HEAT PUMPS INSTALLED VIA THE RENEWABLE HEAT PREMIUM PAYMENT (RHPP) SCHEME Case Studies Report from the RHPP Heat Pump Monitoring Campaign Issued: March 2017 RAPID-HPC authors: Robert Lowe, Lai Fong Chiu, Eleni Oikonomou, Colin Gleeson, Jenny Love, Jez Wingfield, Philip Biddulph Confidentiality, copyright & reproduction: This report is the copyright of RAPID-HPC, prepared under contract to BEIS. The contents of this report may not be reproduced in whole or in part, without acknowledgement. BEIS and RAPID-HPC accept no liability whatsoever to any third party for any loss or damage arising from any interpretation or use of the information contained in this report, or reliance on any views expressed herein. ©RAPID-HPC 2017. Table of Contents List of figures ........................................................................................................................ 5 List of tables ....................................................................................................................... 11 Nomenclature ..................................................................................................................... 13 Context ............................................................................................................................... 15 Acknowledgements ............................................................................................................ 16 Executive Summary ............................................................................................................ 17 Background to this report ....................................................................................................... 17 The quality of heat pump installations .................................................................................... 17 Consumer views of heat pump systems .................................................................................. 18 Consumers’ strategies for control ........................................................................................... 18 Faults ..................................................................................................................................... 19 Cross-checking of site data with monitored data ..................................................................... 19 Calculated performance of heat pumps and factors impacting performance ............................ 20 Factors influencing performance ............................................................................................. 20 Technical Summary ............................................................................................................ 22 Context .................................................................................................................................. 22 Aims and objectives ............................................................................................................... 22 Methodology ......................................................................................................................... 23 Sites/households selected for study ........................................................................................ 23 Results ................................................................................................................................... 24 Complexities in data collection ............................................................................................... 24 Complexity of heat pump system design ................................................................................. 27 Revision of estimates of heat pump performance ................................................................... 28 Heat pump performance ........................................................................................................ 28 Occupants’ experiences and perceptions ................................................................................ 32 Conclusions and recommendations ......................................................................................... 33 1 Introduction and background ...................................................................................... 36 2 Aims and objectives .................................................................................................... 37 3 Design and methods .................................................................................................... 38 1 3.1 Sampling method ........................................................................................................ 38 3.1.1 The estimation and role of SPFs in the case study process .......................................... 38 3.1.2 Recruitment of participants .......................................................................................... 39 3.1.3 Case study sampling ...................................................................................................... 41 3.2 Field procedure ........................................................................................................... 43 3.2.1 The pilot ........................................................................................................................ 43 3.2.2 Case studies investigated .............................................................................................. 44 3.2.3 Interview and site investigation routine ....................................................................... 51 3.3 Data management and analysis ................................................................................... 52 3.3.1 Data operations............................................................................................................. 52 3.3.2 Data analysis ................................................................................................................. 52 3.4 Presentation of results and analysis ............................................................................. 53 4 Anatomy of the case study sample and associated variables ...................................... 55 4.1 SPFs across the cases and data samples ....................................................................... 55 4.2 Social information and decision making ....................................................................... 58 4.2.1 Household characteristics ............................................................................................. 58 4.2.2 Factors influencing the installation of HPs.................................................................... 58 4.3 Dwelling information................................................................................................... 59 4.3.1 Dwelling characteristics ................................................................................................ 59 4.3.2 Ventilation patterns ...................................................................................................... 60 4.4 Technical information on heat pumps .......................................................................... 61 4.4.1 System characteristics ................................................................................................... 61 4.4.2 Installation and metering issues ................................................................................... 64 4.5 Control and usage of heating systems .......................................................................... 69 4.5.1 Space heating (SH) ........................................................................................................ 70 4.5.2 Domestic hot water (DHW) ........................................................................................... 74 4.6 Overall energy cost...................................................................................................... 75 4.7 Occupant perception of comfort and satisfaction ......................................................... 78 4.7.1 Occupant satisfaction with current and previous system ............................................ 78 4.7.2 Occupant perception around comfort with HP ............................................................ 83 4.7.3 Occupant experiences of the HP ................................................................................... 83 5 Case and cross-case comparison ................................................................................. 88 5.1 Introduction ................................................................................................................ 88 5.2 Strategy for sub-sampling and cross-case comparison .................................................. 88 2 5.3 An analytic matrix ....................................................................................................... 91 5.4 Exploring physical factors influencing performance ...................................................... 92 5.4.1 System insulation and heat loss in poorly performing cases ........................................ 94 5.4.2 System insulation and heat loss in well-performing cases ......................................... 110 5.4.3 Well-performing cases without overt metering issues – CS14 and CS19 ................... 113 5.4.4 Well-performing cases with suspected metering issues – CS13 and CS18 ................. 113 5.4.5 CS20 – a well performing, space heating only ASHP .................................................