GSHTPS Thermal Pile Design, Installation & Materials Standards (by GSHPA)

Thermal Pile Design, Installation and Materials Standards (version 2), published by GSHPA, the Ground Source Heat Pump Association

The Ground Source Heat Pump Association (GSHPA) recognises the industry, including consumers and industry members, require installation standards in order to maintain a high level of installation quality whilst protecting the environment to ensure Best Practice. The standards are aimed at the designers and installers of ground source systems, architects and engineers specifying ground source systems and main and sub-contractors involved with installer companies supplying ground source systems or designs. The standards should also prove useful for the general public and anybody with an interest in the subject, when considering a ground source installation.

This thermal pile standard has been developed from the GSHPA Vertical Borehole Standard (GSHPA 2017). Additional information is provided in the appendices on certain topics associated with ground source systems that are either the subject of current research or where further research is required, and it is not possible to give prescriptive guidance on these topics at this time.

The GSHPA standards are designed to be a concise document providing information for the materials and general specification of a closed-loop thermal pile system. The standards also cover internal pipework up to and including manifolds and/or flushing valves/arrangements up to the entrance of header pipes into the plant room. They are not designed to be an installation or training manual and the standards must be referred to in conjunction with recognised design qualifications and training programmes. No responsibility can be accepted by the GSHPA for the performance of GSHP systems.

The standards are designed to enable anybody reading them to quickly reference minimum materials specification, techniques and qualification requirements and ensure they either comply with the standards (or exceed them) or are employing companies and personnel who comply with the standards (or exceed them). Where references are not yet available to support the standard, additional information is provided in appendices.

Contents

1. PREAMBLE

1.1 Introduction

1.2 Definitions

1.3 Scoping Statement

1.4 Acknowledgements

2. REGULATORY & GOVERNMENT AGENCY REQUIREMENTS

2.1 Health & Safety at Work Act 1974, Management of Health & Safety at Work Act 1999

2.2 The Construction (Design & Management) Regulations 2015 (CDM 2015)

2.3 Groundwater Protection: Principles and Practices (GP3)

2.4 The Coal Authority

2.5 Building Regulations and Other Certification Material

2.6 Planning Permission Requirements

2.7 Notification to the British Geological Survey

2.8 Party Wall Issues 11

2.9 ICE Specification for Piling and Embedded Retaining Walls (SPERW) 2007

2.10 Design Codes

2.11 Installation Standards

2.12 Other Codes of Practice, Guidance and References

3. CONTRACTUAL RESPONSIBILITIES

3.1 Preface

3.2 ICE SPERW

3.3 Employer or Client

3.4 Engineer

3.5 Pile Designer

3.6 GSHP Designer

3.7 Mechanical and Electrical (M&E) Designer

3.8 Main Contractor

3.9 Piling Contractor

3.10 GSHP Contractor

3.11 Groundworks Contractor

3.12 M&E Contractor

3.13 Loop and Pipework Testing Responsibilities

3.14 Monitoring and Checking Performance against Design Criteria

4. DESIGN & INSTALLATION: PERSONNEL & TRAINING REQUIREMENTS

4.1 Introduction

4.2 Pile Designer (Structural and Geotechnical)

4.4 M&E Designer

4.5 Main Contractor

4.6 Piling Contractor

4.7 GSHP Contractor

4.8 Thermal Loop Fabricators

5. DESIGN METHODS & COMPLIANCE

5.1 General GSHP Design Approach

5.2 Desk Study

5.3 Site Investigation

5.4 Pile Loads

5.5 Thermal (Heating & Cooling) Load Data

5.6 Pile Design

5.7 GSHP Design

5.8 Floor Slab Construction

5.9 Results of System Design Calculation

6. THERMAL RESPONSE TESTING

6.1 Aim of the Test

6.2 Testing Strategy

6.3 Borehole Thermal Response Test

6.4 Pile Thermal Response Test (Up to 300mm Diameter)

6.5 Pile Thermal Response Test (Greater than 300mm Diameter)

7. THERMAL LOOP & JOINTING: METHODS & MATERIALS

7.1 Pipe Materials & Tolerances

7.2 Fusion Processes

7.3 Mechanical Fittings

7.4 Specific Pipe Application & Dimensional Specification

7.5 Off Site Factory Manufacture & Quality Control

7.6 Pipe & Fittings Sizing

7.7 Transition Fittings

7.8 Leak Free Installation

8. THERMAL PILE CONCRETE

8.1 General

8.2 Concrete Thermal Conductivity

9. LOOP INSTALLATION, PROTECTION, TRIMMING AND HEADERING

9.1 Pipe and Loop Delivery to Site and Storage

9.2 Thermal Loop Installation

9.3 Protection Measures for Thermal Loops

9.4 Pile Trimming

9.5 Header Pipe Installation

10. FLUSH, PURGE & PRESSURE TEST OF GROUND HEAT EXCHANGER

10.1 Quality Control

10.2 On-site Pressure Testing

10.3 Tests During Pile Construction and Trimming - Table 10.1 (Hold points 1-7)

10.4 Purging the System

10.5 Final Stage Tests - Table 10.1 (Hold points 8 & 9)

11. INDOOR PIPING & VALVE VAULTS

11.1 Circulator Sizing and System Components

11.2 Valve Vault & Indoor Piping Requirements

12. THERMAL TRANSFER FLUID REQUIREMENTS

12.1 Thermal Transfer Fluid Selection, Use & COSHH Requirements

12.2 Specific Thermal Transfer Fluid Requirements

12.3 Inhibitors & Biocides

12.4 Safety Notices for Thermal Transfer Fluids

12.5 Filling of Thermal Loops with Thermal Transfer Fluid

13. DESIGN DRAWINGS AND AS BUILT RECORDS

13.1 Design Drawings

13.2 Installation Records

13.3 Re-instatement

14. MONITORING AND CHECKING PERFORMANCE

15. SUBMITTALS AND ALTERATIONS TO STANDARDS

15.1 Requirement for a Change Process

15.2 Persons or Organisations Permitted to Submit Change information

15.3 Standards Change Process

15.4 Standards Change Review and Outcome

15.5 Dispute of Outcome

15.6 Records of Changes

16. LIST OF RECOMMENDED READING MATERIALS

APPENDICES