Harnessing energy from water in the ground for heating and cooling
This Code of Practice has been produced as a joint project between the Chartered Institution of Building Services Engineers (CIBSE) and the Ground Source Heat Pump Association (GSHPA) with the backing of the Heat Pump Association (HPA). The work has been supported by the UK Department for Business, Energy and Industrial Strategy (BEIS).
Groundwater source heat pumps (GWSHPs) have huge potential and are an underused technology in the UK. Harnessing renewable energy from aquifers and mine water represents a huge opportunity to provide low carbon heating and/or cooling to buildings. However, if GWSHPs are to form a significant part of our future low carbon energy infrastructure they need to be designed, built, operated and maintained to a high quality to deliver customer satisfaction. This Code of Practice has been produced to help achieve these aims by raising standards right across the supply chain and to encourage adoption of the technology.
Setting minimum requirements (and recommending best practice) should provide greater confidence for specifiers and developers. This Code of Practice can also be included in the tendering/contracting process to specify minimum requirements for a project. The adoption of this Code of Practice by developers could ultimately be used to provide assurance to customers and property purchasers that their GWSHP scheme has followed a set of design, installation and commissioning standards. This Code of Practice should therefore have a significant effect on the GWSHP market by boosting confidence in the technology.
The Code of Practice can also be included in the tendering/contracting process to specify minimum requirements for a project. The adoption of this Code by developers could ultimately be used to provide assurance to customers and property purchasers that their GWSHP scheme has followed a set of design, installation and commissioning standards. It is anticipated that the Code should therefore have a significant effect on the GWSHP market by boosting confidence in the technology.
CIBSE, GSHPA and HPA are also working to develop training to ensure the skills necessary to implement the Code of Practice are available across the sector.
The draft of this Code of Practice was prepared by a consortium led by Themba Technology Ltd. under contract to CIBSE and in association with HPA and GSHPA.
Phil Jones (Chair of CP3 steering committee) says “The rapid decarbonisation of the electricity grid means that heat pumps are THE low carbon solution for providing heating and cooling in buildings. Ground water provides a relatively constant temperature source, making GWSHPs an efficient technology right across the year. This new Code of Practice sets out minimum standards to give the buildings sector confidence in applying GWSHPs correctly.”
Linked titles
CIBSE has so far published two other Codes of Practice in this area:
- CP1: Heat Networks: Code of Practice for the UK (here) and supported by 'A Guide for Building Owners and Developers' (here)
- CP2: Surface Water Source Heat Pumps: Code of Practice for the UK (here).
Contents:
Part A: How to use this Code
A1 Introduction
A1.1 Strategic purpose
A1.2 What is an open-loop groundwater source heat pump?
A1.3 Why install an open-loop groundwater source heat pump?
A2 Readership and scope of the Code of practice
A2.1 Readership
A2.2 Scope
A3 Structure of the Code of Practice
A3.1 Themes
A3.2 Responsibilities
Part B: Challenges and opportunities
B1 The heat pump
B1.1 Types of heat pump
B1.2 Heating and cooling
B1.3 Key design issues
B2 Groundwater sources and their characteristics
B2.1 Aquifers: the occurrence of groundwater in the subsurface
B2.2 Water wells and boreholes
B2.3 Groundwater from flooded mines and quarries
B3 Types of installation
B3.1 Open-loop doublet systems: abstraction with injection to aquifer
B3.2 Open-loop systems: abstraction only with discharge to surface water or sewer
B3.3 Standing column wells (SCWs): abstraction and injection to the same well or shaft
B3.4 Hybrid and mixed technologies
B4 Challenges and opportunities
B4.1 Heat networks (load side)
B4.2 Source side networks (SSN)
B4.3 Multivector and multivalent systems
B4.4 Retrofit installations 43
B4.5 Free cooling and heating 44
B4.6 Aquifer thermal energy storage (ATES) 48
Part C: The Requirements
C1 Stage 1: Preparation and briefing
C1.1 Objective 1.1: To commission the project in accordance with the Code of Practice
C1.2 Objective 1.2: To develop the specification/project brief
C2 Stage 2: Feasibility
C2.1 Objective 2.1: To identify and quantify the groundwater source
C2.2 Objective 2.2: To determine what permissions are necessary to access the groundwater
C2.3 Objective 2.3: To determine heat pump location and groundwater abstraction and discharge details, including cost estimates
C2.4 Objective 2.4: To accurately estimate peak and seasonal heating and cooling demands
C2.5 Objective 2.5: To agree suitable load-side operating flow rates, temperatures and control strategies
C2.6 Objective 2.6: To select the most appropriate heat pump system
C2.7 Objective 2.7: To assess operation and maintenance needs and costs
C2.8 Objective 2.8: To conduct a financial analysis to comprehensively evaluate the installation options
C2.9 Objective 2.9: To assess environmental impacts and benefits
C2.10 Objective 2.10: To analyse risks and carry out a sensitivity analysis
C3 Stage 3: Design
C3.1 Objective 3.1: To design for safety in construction, operation and maintenance
C3.2 Objective 3.2: To accurately determine peak heating and cooling demands and seasonal energy consumption profiles
C3.3 Objective 3.3: To accurately test and quantify the groundwater supply
C3.4 Objective 3.4: To design the groundwater abstraction and discharge details
C3.5 Objective 3.5: To apply for the permissions necessary to access the groundwater
C3.6 Objective 3.6: To specify the most appropriate heat pump system
C3.7 Objective 3.7: To design an efficient load-side hydraulic system interface
C3.8 Objective 3.8: To evaluate environmental impacts and benefits
C3.9 Objective 3.9: To design a data collection system to accurately record performance
C3.10 Objective 3.10: To update and refine the risk register and sensitivity analysis
C3.11 Objective 3.11: To confirm a cost statement for the main system elements of the project
C4 Stage 4: Construction and installation
C4.1 Objective 4.1: To reduce adverse environmental impacts of construction
C4.2 Objective 4.2: To reduce health and safety risks
C4.3 Objective 4.3: To install the groundwater abstraction and discharge system in accordance with the design
C4.4 Objective 4.4: To pressure test, flush clean, purge and fill all pipework and plant
C5 Stage 5: Commissioning
C5.1 Objective 5.1: To follow a structured commissioning management plan
C5.2 Objective 5.2: To commission the source side of the heat pump installation
C5.3 Objective 5.3: To commission the heat pump and immediate supply-side equipment
C5.4 Objective 5.4: To commission and calibrate the performance data collection system
C5.5 Objective 5.5: To carry out a formal handover and provide appropriate and comprehensive information to the operations team
C6 Stage 6: Operation and maintenance
C6.1 Objective 6.1: To reduce health and safety risks to staff, customers and the general public in operation and maintenance
C6.2 Objective 6.2: To minimise environmental impacts of operation and maintenance
C6.3 Objective 6.3: To deliver a maintenance schedule that maximises system efficiency, reliability and asset life
C6.4 Objective 6.4: To provide appropriate monitoring and reporting, including reliability and CO2 emissions
C7 Stage 7: Decommissioning
C7.1 Objective 7.1: To decommission the heat pump
C7.2 Objective 7.2: To decommission the source side
Appendices
Appendix A: Glossary of terms and acronyms
Appendix B: Key legislation
Appendix C: Useful contacts
Appendix D: Calculating system efficiency
Appendix E: Environmental best practice checklist
Appendix F: References and further reading
Index
Acknowledgements
Chair: Phil Jones, CP3 Steering Committee; Chair, CIBSE CHP and District Heating Group
John Findlay, Past Chair, Ground Source Heat Pump Association (GSHPA)
Authors:
The draft of this Code of Practice was prepared by a consortium led by Themba Technology Ltd. under contract to CIBSE and in association with HPA and GSHPA.
Lead authors: Nic Wincott, Jen Billings
Steering Committee: Project Team
Phil Jones (Building Energy Solutions) (Chair); David Matthews (Themba Technology Ltd.); Eileen Bell (CIBSE)
Steering Committee members
Corinna Abesser (British Geological Survey); Dave Banks (Holymoor Consultancy Ltd.); Mark Barson (Vaillant); Nick Boid (IFTech Ltd.); Anthony Coumidis (McBains Cooper); Chris Davidson (GeniusEnergyLab); James Dickinson (Buro Happold); John Findlay (Carbon Zero Consulting); Graham Hazell (Heat Pump Association); Roger Hitchin (BRE and CIBSE); Ross Lowrie (Environment Agency); Robert Mack (Glen Dimplex Heating and Ventilation); Tommy Moody (BEIS); Matthew Maskell (Glen Dimplex Heating and Ventilation); Colin Pearson (BSRIA); Mark Trevaskis (Lowara Xylem); Guus van Gelder (Groenholland UK Ltd.)
Other acknowledgements
Comments were received from corresponding members, including: Michael Crane (GI Energy); Geoff Ellison (Dragon Drilling); Sasha Krstanovic (Aecom); Martin Preene (Preene Groundwater Consulting)
Referees
Robin Curtis (GeoScience Ltd.); James Dickinson (Buro Happold); Roger Macklin (Hoare Lea LLP)
Consultation
This Code of Practice was made available for public consultation between 22 January and 21 February 2018.