Comprehensive Testing

Identification of Critical Issues

Enhanced Resident Experience


A prominent private developer was facing challenges with the operation of the chilled water (CHW) network. The development located in Battersea consists of 900 units divided into six blocks, which are being constructed as individual entities. In addition to the heat network, the development has CHW networks that circulate chilled water produced from electric chillers on the roof. The twin-pipe CHW network provides cooling to dwellings via cooling interface units (CIU) in every dwelling. An example of the CIU is shown in Figure 1 below. The CIUs are designed to provide sufficient cooling temperatures to the fan coil unit (FCU) within each room.

Figure 1: Cooling interface unit in each dwelling


The developer’s main reason for collaborating with FairHeat was to pinpoint areas that didn’t meet the required standards and to seek guidance on possible measures to enhance the performance of each unit. Additionally, the developer emphasised the importance of establishing and documenting the achieved performance metrics before handing over the properties. The overarching aim was to guarantee that the systems were constructed according to the design blueprints and would operate optimally when residents moved in, ensuring their comfort and resulting in reduced energy bills. Poor installation and commissioning of these systems lead to decreased resident comfort and reduced CHW network performance and efficiency.

FairHeat Solution

FairHeat carried out cooling acceptance tests, which is a performance testing that ensures compliance of systems. This involved inspecting and testing the CIU and the cooling delivery mechanisms.

Cooling acceptance tests required visual inspections of the insulation on the CIU and associated pipework, ensuring the heat meter and controller were functioning as they should and ensuring the cooling set point was correct.
Next, the standby performance was investigated based on heat meter readings to ensure the CIUs are not being bypassed.

The ability of the CIUs to provide sufficient cooling temperatures to the FCU within each room was tested to complete the acceptance test. Cooling was turned on in all the rooms and the air temperature being produced from each FCU was measured. This was to ensure each room with an FCU could be cooled down sufficiently, but also to check how the cooling system performed during operation, which is crucial for the overall performance of the CHW network.

Acceptance testing ensures installation, commissioning and operation are as per design requirements and performance specifications.

Whenever performance discrepancies were detected, FairHeat collaborated with the developers contractors and equipment suppliers to pinpoint and implement solutions. The deliverables from this engagement included detailed dwelling-level reports and Acceptance Testing pro-forma reports for each unit.


Upon conducting the tests, FairHeat identified several areas of concern within the development.

A notable number of units were bypassing during the initial assessment, which had a significant impact on the efficiency of the CHW network and the overall cooling performance within these dwellings.

Additionally, some of the pipework was inadequately insulated, with certain sections showing signs of a compromised vapour seal. An example of exposed pipework is shown in Figure 2 below. This posed a significant risk as chilled pipework is prone to condensation, which can lead to pipework corrosion and potential future leaks.

Furthermore, certain CIU pumps were found to be non-functional, resulting in a complete lack of cooling in the affected flats. Some dwellings also had FCUs that did not operate across all thermostat modes, leading to suboptimal cooling. High levels of air were detected in the pipework of some units, causing noise disturbances when the cooling system was in operation.

Figure 2: Sections of cooling pipework that are uninsulated

In conclusion, these findings underscored the importance of FairHeat’s testing, ensuring to the developer that residents would experience optimal living conditions in their new homes.

FairHeat conducted detailed cooling acceptance tests on the development. The assessment was instrumental in ensuring that the systems adhered to design specifications and industry standards and would operate efficiently once occupied.

The testing revealed several significant concerns, including bypassing in a notable number of dwellings, inadequately insulated pipework, and non-functional CIU pumps. These findings were crucial in pinpointing areas that required immediate attention to ensure optimal performance.

The proactive approach taken by FairHeat, in collaboration with the developer, aimed to guarantee resident comfort and efficiency. By addressing the identified issues, the development ensured that future residents would benefit from reduced energy bills and an overall enhanced living experience.


Document title
Document title
Document title