GCA RM6237 mini-competition - Clay Farm replacement roof chillers

Cambridge City Council is inviting suppliers from the GCA RM6237 framework to provide the below.

The Clay Farm Community Centre has a modest sized chilled water supply for the use of the Trumpington Medical Practice clinical spaces and two server rooms. Approximately three years ago the existing chillers failed and now need to be replaced. The existing units are:
• Trane CGA 040 X 1 chillers packaged with common flow pipework
• Operating at 10°C flow and 16°C return temperatures.
• Controlled by BMS for two units to run and one unit in standby.
• Each chiller rated to supply 15.8 kW of cooling.

An additional room will also need to be cooled. Plant room T04 on the 3rd floor, as seen in Appendix G – Drawing (58) 001 R, 3rd floor plant room layouts, will need to maintain temperature at or below 20°C.

All relevant as fitted drawings can be found at the back of this document and consist of:
• Appendix A – Drawing (56) 002 R, 1st floor heating and chilled water layout
• Appendix B – Drawing (56) 003 R, 2nd floor heating and chilled water layout
• Appendix C – Drawing (56) 004 R, 3rd floor heating and chilled water layout
• Appendix D – Drawing (56) 005 R, 4th floor heating and chilled water layout
• Appendix E – Drawing (56) 006 R, roof plan heating and chilled water layout
• Appendix F – Drawing (57) 003 R, 2nf floor ventilation layout
• Appendix G – Drawing (58) 001 R, 3rd floor plant room layouts
• Appendix H – Drawing (58) 005 R, chilled water schematic
• Appendix I – Drawing (58) 006 R, 4th floor plant room layouts

Below is the requirement that will assist you in completing your submission for this work. The criteria for assessing your bid will be in Section 5 Submission and Quality and Section 6 Pricing
Requirements for the project.

Removal and replacement of three chillers similar to the existing Trane CGA 040 X 1, also designed to meet the additional cooling demand of plant room T04 on the 3rd floor. Existing information known consists of:
• 10°C flow and 16°C return temperatures.
• Controlled by BMS for two units to run and one unit in standby.
• Each chiller rated to supply 15.8 kW, or more, of cooling.
• Reusing or supplying new Unistrut and roof supports.
• Connect to the existing BMS control cabling and test working as originally designed.
• Ensure chilled water circuit is cleaned and pressure tested before being put into operation (air-dirt separator installed).
• Chilled water indoor units (x4) and chiller batteries (x3) will need to be serviced, which includes filter cleaning and check that condensate trays, drain and pumps perform as needed when the chilled water service is returned.

Access arrangements for this project should be assessed and proposed after a site visit before 14/09/2026. The building has a large access hatch and lift to the floor below roof level, though a crane could be considered for practicality. Any investigation and temporary works design required for crane use will be the responsibility of the contractor and not Cambridge City Council. Cambridge City Council will require evidence to be supplied all works have been assessed and appropriately planned before any work can begin.

This project is expected to produce, from the original PDF As Fitted drawings, updated As Fitted drawings which details the finished installation in .dwg format and supply a drawing in the level four plant room using a durable, waterproof synthetic paper, such as ToughCAD, DuraPlans or similar. Also, the contractor is expected to carry out seasonal commissioning in July 2027.

The tender will be a competition based on the Low Value Purchase System (agreement RM6237). The contract will be a completed version of the LVPS Buyer Contract (Buyer-Supplier-Contract-v1.0.docx), which will be completed and sent out after tender return.