Pre-Commissioning Monitoring
Several developers have experienced significant issues with poor pre-commissioning activities on the heat network systems. These issues have primarily been associated with:
- Inappropriate filling processes and a lack of attention paid to avoiding system stagnation: This has led to corrosion taking place prior to handover and major intervention measures to arrest the corrosion, causing programme delays and permanent corrosion damage.
- Insufficient levels of sampling in accordance with BG 29: This has led to issues not being detected before they escalate. This had led to undetected corrosion and significant remedial measures (e.g. installation of additional side stream filtration).
- A lack of record keeping and trend analysis: Corrosion management and prevention should focus on analysing trends in KPIs (inhibitor levels, dissolved iron etc.). Without regular samples and graphical trend analysis, corrosion issues are difficult to diagnose.
FairHeat offer a full pre-commissioning monitoring regime, whereby:
- The method statements for the water treatment management of the system during construction are reviewed to ensure they contain the right approaches to managing corrosion.
- Water quality monitoring, whereby sample results are assessed regularly and remedial measure advice is provided to keep the system inert and corrosion free.
Commissioning method statements for key plant are often generic, not detailed enough and/or not site specific with regards to the particular hydraulic arrangement or set point requirements. If these are not site specific, manufacturers can arrive onsite and carry out commissioning not appropriate to the system, or not to the design requirements. FairHeat offer a method statement review service that ensures the right level of detail is applied and that the intended approach will achieve the design intent in operation.
Several developers have experienced significant issues with poor system control, stable temperatures and boiler sequencing post-handover. FairHeat have developed a process for a system load test that is proving successful at diagnosing such issues and ensuring remedial measures are carried out prior to the system being handed over, which is now a minimum requirement in CP1 2020.
Historically, heat network commissioning has had a main focus on the centralised plant room with the dwelling commissioning not given the attention it requires, often left until the end of a project and rushed to meet handover deadlines.
Witnessing of dwelling level commissioning has typically only been required on a small number of end points, or only very high-level inspections/tests. This has resulted in installation and commissioning issues being missed, and not picked up until the resident has moved in, when it is often much more costly and time intensive to rectify. Poor performance of end points is often associated with elevated flow rates and return temperatures, where a few poorly performing units can have a detrimental effect on the heat network’s performance and efficiency.
Acceptance Testing allows FairHeat to independently validate installation, commissioning and operation of all end points through a rigorous testing procedure, as per CP1 2020 minimum requirements and best practice, ensuring that the client and end user are delivered an efficient and reliable service. This process can be applied across all development end points, including dwellings, commercial connections and communal areas.
FairHeat recommend that 100% of all dwellings are Acceptance Tested to ensure the highest quality network and protect system performance, as per the Best Practice requirements of CP1 2020.
Developers experiences a significant amount of cost and management time dedicated to resolving issues that should be resolved prior to practical completion of their M&E services related to their heat networks, associated hot water and space heating systems. Due to competing pressures, the developer’s developments normally have a number of outstanding commissioning issues outstanding post-practical completion (PC). These vary from the Contractor not providing the required handover documentation (e.g., water quality records and commissioning documents) to operational concerns such as equipment commissioning not meeting performance requirements and a diverse range of other issues. Unfortunately, the experience to date has been that these issues are simply not resolved by the Contractor after practical completion, as the project team is demobilised, with the developer often being left with outstanding risks relating to performance and operability of their systems.
FairHeat supports the developer in project managing the process to ensure that outstanding issues at practical completion are closed out in a timely manner and that any costs are recovered from contractor retentions.
