School Output Specification - GOV.UK

1 School Output Specification Technical Annex 2F: Mechanical Services and Public Health Engineering November 2021. 1. Document Control Revision Status Date Author Amendment C01- A 2016-07 n/a Includes initial working towards OS. C06 2017. C07 A 2017-11 n/a Issued as OS 2017. C08 A 2019-05-11 n/a Revised to incorporate end user feedback, evidence collected and updates to applicable standards C09 A 2020-05-29 n/a Amendments to natural ventilation and ventilation systems; pipework; water storage and temperature monitoring;. underground drainage; and fume cupboards C10 A 2020-11-30 n/a Amendments to heating, hot water systems, and plant rooms. Fit for purpose' replaced with clearer explanation P01 S2 2021-04-19 AWI General technical review and update, introduction of Uniclass coding, alignment with draft BB100 and improved performance in use standards P02 S2 2021-10-20 AWI MMC1 Consultation Markup Minor non-material changes made.

2 Corrections and errors addressed P03 S2 2021-11-23 AWI Non-material changes shared with MMC & CF21. C11 A 2021-11-23 AWI publication 2. Contents 1. Introduction 12. Overview 12. 2. Common Requirements 13. Overview 13. Refurbishment 13. 3. Pipework 15. General Requirements 15. lthw Pipework 16. Domestic Hot and Cold Water Systems 17. Domestic Hot and Cold Water Pipework 17. Gas Pipework 19. Refrigerant Pipework 19. Reference Standards for Pipework 19. All Pipework 19. lthw pipework 20. Domestic Hot and Cold Water Pipework 20. Fuel Pipework 21. Refrigeration Pipework 21. Pumps 21. lthw Pumps 21. Domestic Hot and Cold Water Pumps 21. Reference Standards for Pumps 21. valves , Fittings and Components 22. lthw valves , Fittings and Components 22. Domestic Hot and Cold Water System valves , Fittings and Components 23. 3. Reference Standards for valves , Fittings and Components 25. 4. Mechanical Services 27. Mechanical Services Overview 27.

3 Plant Room Requirements 27. Heating Systems 28. Overview 28. Operative Temperatures 28. Heat Generating Systems and Main Plant 28. Heat Sources 29. Energy Networks 30. Heat Pumps 30. Ground Source Heat Pumps 31. Air Source Heat Pumps 32. Alternative Low and Zero Carbon Heat Sources 32. Boilers 33. Heating Distribution Systems 34. Heating Emitters 36. Radiant Temperature Difference 39. Underfloor Heating 41. Commissioning and Handover of Heating Systems 42. Hand Dryers 42. Reference Standards 43. Ventilation Systems 44. Overview 44. Indoor Source Control 45. Radon Remediation 46. Natural Ventilation Systems 46. Mixed-mode Systems 46. Mechanical Ventilation Systems 47. Local Extract Ventilation 47. 4. Ventilation Controls 48. Distribution 48. Ductwork 48. Dampers 49. Ventilation of Plant Rooms 49. Natural Ventilation Units 49. Fans 50. Air Handling Units 51. Location of Ventilation Air Intakes and Exhausts 52.

4 Air Terminal Devices 52. Testing of Dampers and Weather Louvres 53. Reference Standards 53. 5. Ventilation of General Teaching Spaces and Learning Resource Areas 55. Overview 55. Reference Standards 56. 6. Ventilation for Particular Areas and Activities 57. General 57. Office Accommodation 57. Local Extract Ventilation 57. Reference Standards 59. Ventilation of Large and Circulation Spaces 59. Large Spaces 59. Sports Halls and Assembly Halls 60. Circulation Spaces, including Atria and Corridors 61. Dining Areas 61. 7. Specialist Ventilation Systems 62. General 62. School Kitchen Ventilation 62. General Requirements 62. Grease Filters and Odour Control 63. 5. Reference Standards 63. Food Room Ventilation 64. Design Criteria 64. Gas Interlocks 66. Reference Standards 67. ICT Server Room Ventilation 67. Overview 67. General Requirements 67. Ventilation Systems, Air Flow Rates and Heat Loads 67. Local Exhaust Ventilation in DT studios, workshops and DT prep rooms 68.

5 Overview 68. Design Criteria 69. Local Exhaust Ventilation (LEV) Systems 70. General Requirements 70. Laser Cutters and 3D Printers 71. Wood Dust Extract Systems 72. Centralised Wood Dust Extract Systems 73. Reference Standards 78. Science Fume Cupboard Ventilation 78. Overview 78. General Requirements 78. Design Criteria 79. Bunsen Burners 80. Fume Cupboards 80. Science Prep Rooms 82. Chemical Stores 82. Ventilation Controls 82. Fume Cupboard Exhausts 82. Reference Standards 83. Ventilation for SEN(D) 83. 6. General Requirements 83. Infection Control 85. Reference Standards 86. 8. Mechanical Air Conditioning Systems 87. The Cooling Hierarchy 87. Refrigerant Based System 88. Variable Refrigerant Flow (VRF) and Split Systems 89. 9. Gas Services 90. General Requirements 90. Gas Interlocks 91. Gas Safety Interlocking by Environmental / CO2 Monitoring 93. Carbon Monoxide, Carbon Dioxide and Flammable Gas Detectors 94.

6 Overview 94. Carbon Monoxide Detectors 94. Carbon Dioxide Detectors 95. Flammable Gas Detectors 95. Gas Systems in Food Rooms 95. Science Laboratory Gas Systems 96. Overview 96. Reference Standards 96. 10. Thermal Comfort 98. Overview 98. Thermal Comfort Criteria 98. Operative Temperature Range 99. Local Thermal Discomfort Caused by Draughts 101. General Requirement 101. Natural Ventilation Systems 101. Forced Draught Systems 102. Performance Standards for the Avoidance of Overheating 105. Assessment of Performance in Use 111. 7. Overview 111. Performance in Use Standard for Overheating 112. Thermal Comfort for Special Education Needs 113. Reference Standards 113. 11. Design Calculations for Ventilation and Thermal Comfort 114. Overview 114. Ventilation Calculations 114. Ventilation Opening Areas 115. Mechanical Ventilation 117. Thermal Comfort Calculations 117. Weather Files for Overheating Risk Assessment 117.

7 Internal Gains for Overheating Risk Assessment 118. Reference Standards 119. 12. Public Health Engineering Services 120. Overview 120. Drainage Systems 120. Foul Drainage Above-ground 120. System Description 120. Performance Criteria 122. Routes 122. Access Points 122. Rainwater Drainage 122. Design Parameters 123. System Description 123. Drainage Below Ground 123. Foul Water System 124. Surface Water System 125. Domestic Water Services 125. Cold Water Services 125. System Description 125. 8. Drinking Water Outlets, Fountains and Bottle Fillers 128. Science Laboratories and Refuse Areas 128. Hot Water Services 129. Reference Standards 131. 13. Handover Requirements 132. Overview 132. Soak Testing 132. Documentation 133. Commissioning and Building Performance Evaluation 134. Demonstration and Training 134. Reference Standards 135. 14. Demonstrating Compliance 136. Overview 136. 9. Table of Figures Table 4-1 Minimum panel height above finished floor level (m) / Radiant Temperature Asymmetry RTA = 7K 40.

8 Table 4-2 Minimum panel height above finished floor level (m) / Radiant Temperature Asymmetry RTA = 5K 40. Table 4-3 maximum floor surface temperatures 41. Table 6-1 Recommended minimum local extract ventilation rates 59. Table 6-2 Design parameters for sports halls / Summary of environmental standards for sports halls 60. Table 7-1 Fume Ventilation Systems 72. Table 7-2 Types of dust extraction (table adapted from CLEAPSS publication L225) 77. Table 7-3 Science Laboratories Minimum Exhaust Rates 79. Table 7-4 Ventilation performance criteria for Special Schools and Designated Units 85. Table 9-1 Summary of interlock requirements according to appliance type 93. Table 10-1 Categories of space and activity 99. Table 10-2 Operative temperatures to be achieved during the heating season measured at from the floor in the centre of the room 101. Table 10-3 Comfort categories for cold draughts 103. Table 10-4 Recommended draught criteria for mechanical ventilation systems to provide thermal comfort 104.

9 Table 10-5 Adaptive thermal comfort category to apply 107. Table 10-6 Suggested applicability of the categories and their associated acceptable temperature range for free running' buildings (from BS EN 16798-1: 2019) 109. 10. Summary Technical Annex 2F provides the minimum requirements for mechanical services including public health engineering, pipework, heating and ventilation systems, thermal comfort and drainage. It is to be read in conjunction with the Generic Design Brief (GDB) and the School Specific Brief (SSB). Review Date Review dates for this document shall be at 6-month intervals. Who is this publication for? This document is for technical professionals involved in the design and construction of School premises, as part of the Employer's Requirements of the DfE Construction Frameworks (the DfE Construction Framework 2021 and the Offsite Schools Framework (incorporating Modular and MMC delivery) (MMC)).

10 It may also be used as the basis of similar documentation for other procurement routes using the Output Specification . Uniclass Codes This document captures Uniclass codes for the management of exchange of information. To access all codes and associated titles reference should be made to Uniclass 2015 | NBS. ( ). 11. 1. Introduction Overview This document is one of the Technical Annexes that forms part of the Generic Design Brief (GDB). [PM_10_20]. The definitions listed in GDB shall apply to this Technical Annex and all other parts of the Output Specification . [PM_10_20]. This document shall be read in conjunction with the GDB and all other Technical Annexes as well as the SSB, including the School -specific Annexes. [PM_10_20]. This document sets out the required technical standards and performance criteria for mechanical services and public health engineering. [PM_10_20]. The information exchange required at each stage of the design, build and completion process is detailed in the DfE's Exchange Information Requirements (EIR).