Low Carbon Options Appraisal
The requirements for a low carbon heating system retrofit for a heat network are often poorly understood by clients, which may lead to sub-optimal systems being installed, and ultimately high capital costs and high costs of heat for residents.
To avoid these issues and help clients achieve net zero targets, FairHeat conducts:
- Options appraisal of potential central heat generation strategies – e.g. boilers, electric boilers, heat pumps and hybrid approaches
- Peak load and sizing assessment to determine the capacity of generation plant
- Hourly load assessment to determine the optimal plant size and thermal store arrangements
- High level assessment of the capital costs and annual running costs
- Risk assessment of the proposed options
With the phase out of gas boilers, alternative low carbon heating systems will become more attractive in existing buildings. In some situations, the optimum approach from a cost and resident experience perspective will be to retrofit a low-carbon heat network into an existing building. Due to safety concerns, this is a particularly attractive approach in existing high-rise developments with individual gas boilers in each dwelling.
FairHeat works with clients with existing systems that could convert to low carbon heat networks by undertaking site audits, Stage 3 “Plus” design drawings with equipment and pipe sizing, M&E specifications, design risk assessments, and overall project management.
There are many existing heat networks that require replacement of plant, equipment and pipework due to age and the end of lifetime. For these networks, a like for like replacement is not sufficient to meet performance requirements and allow for the decarbonisation of the heating supply in line with current and future requirements.
FairHeat works with heat network operators with end of life networks on:
- Retrofit site audit
- Stage 3 “Plus” design drawings, with equipment sizes indicated, for the full system
- M&E specification
- Design risk assessment to demonstrate how the design has looked to mitigate risks and document the residual risks that must be further de-risked through detailed design and then managed during construction
There is a significant risk that due to potential variance between the Contractor’s design and the M&E specification, the performance criteria of the plant cannot be met once commissioned. There is also a risk that method statements for plant, equipment and key activities will not be developed fully by the Contractor, which can lead to sub-optimal performance when the system is commissioned. Rectifying such variances, can lead to:
- Significant additional capital costs
- Delays to program
- Long term performance impact and/or O&M costs
It is often found that O&M contractors add additional costs for limited benefits to the heat network. FairHeat works with the client and contractor to optimize the procurement process by:
- Reviewing the Contractor’s technical proposal – i.e. design, technical submittals for key equipment and method statements for key activities, providing feedback to the Contractor and client
- Reviewing the Contractor’s financial proposal – i.e. costs to ensure that they are reasonable and in line with the design requirements
Developers can face issues with Installed equipment not meeting specification and identify where there has been poor workmanship, this could significantly impact performance and/or equipment lifetime. Additionally, developers can experience substantial issues with poor commissioning activities on heat network systems. These issues will lead to sub-optimal outcomes with respect to water quality, equipment operation and reliability of heat supply. FairHeat engage with clients to avoid these issues by:
- Reviewing progress of the installation against specification on site to ensure that any issues are picked up early, with a consequent minimisation of impact on performance and/or program.
- Reviewing progression of the mechanical installation on site an appropriate set of intervals, with site support, witnessing and site visit reports to detail the outcomes and actions required after each site visit.
- Monitoring the commissioning activities for the plantroom with the aim being to ensure that systems are properly commissioned, with correct operating conditions (e.g., water quality) at the point of handover and completion of the works.
- Reviewing commissioning documentation for key equipment and water test results.
- Witnessing equipment and BMS commissioning (e.g. boilers and BMS points)
- Witnessing the final performance test of plant room equipment via load test
- Reviewing handover / O&M documentation with summary note, outlining any issues identified and the updates required
