What Does CIBSE CP1 (2020) Mean For Heat Networks?

Ed Morris, Technical Manager at Altecnic Ltd, discusses the release of CIBSE CP1 ‘Heat Networks: Code of Practice 2020’, and its implications for heat network design, build and maintenance in the UK.

 

What is CP1 (2020): Heat Network Code of Practice?

CIBSE’s updated Code of Practice 'CIBSE CP1' 2020 is a document outlining the minimum standard for heat networks across the UK. By setting minimum requirements and best practice options, it aims to improve the quality of feasibility studies, design, construction, commissioning,  operation and maintenance of heat networks. In addition, its recommendations aim to improve overall energy efficiency and have a positive environmental impact.

A significant difference in this latest edition of CP1 is the focus on providing recommendations for improving both new build and existing heat networks. For the latter, the code of practice offers future-proofing adaptation options to maintain and increase efficiency as technology moves forward.

CP1 (2015) focussed greatly on the role of heat interface units, however, CP1 (2020) takes a more holistic approach to heat network design, looking at how other parts of the system can be vital in improving efficiency. Subsequently, for the first time, minimum and best practice standards have been set for Thermostatic Radiator Valves.

 

Why do we need a Heat Network Code of Practice?

CP1 (2015) has been highly successful in establishing minimum standards to improve the quality of district heating projects from concept through to operation; it has also had a strong influence on the procurement of heat networks. As a result, it underpins much of the work done by the UK Department for Business, Energy and Industrial Strategy (BEIS) Heat Networks Delivery Unit and Heat Networks Investment Project.

 

What are the main recommendations for those designing and working on heat networks?

The timing is certainly right for the release of the CIBSE CP1 2020 document, as since 2015 there have been considerable developments in the UK heat network industry, including significant technological developments with electronic heat interface units.

Within the updated document the key message, in short, is that heat networks need to be designed, maintained and updated with future proofing in mind. For example, the forecast rapid increase in the dominance of heat pump technologies leads to the recommendation that heat networks should be specified and developed with low temperature energy sources in mind. In this scenario, HIUs that operate efficiently with a low primary flow rate, like the Altecnic SATK32107, could be fitted or retrofitted onto older networks to ensure the efficiency of system design is achievable.

In addition, the new guidance sets out best practices and minimum requirements for thermostatic radiator valves (TRV) and their role in achieving the efficiency benefits of the hydronic balancing of a system. For example, pre-settable TRVs become the minimum acceptable standard of TRV fitted in any heat network system, with a pressure independent TRV being best practice. In practice, a pre-settable TRV allows the flow rate to be manually balanced, however, they will experience differential pressure variations as other TRVs close (part load), which results in over and underflow. Thus, a pressure independent TRV, which ensures that the required flow rate is met by automatic balancing to all load conditions, is considered best practice. This meets the reiterated concept that occurs throughout the document which states that TRVs should aim to achieve consistently low return temperatures and optimise flow.

Altecnic’s range of TRVs fulfils the minimum and best practice requirements of CP1, from the liquid filled Ecocal Thermostatic radiator head combined with our  421 Series Commercial Pre-Settable TRV, or the pressure independent 230 Series Dynamical TRV, with a low flow model now available.

As the UK continues on its path to Net Zero, heat networks and heat pump lead systems look to play a significant role in this achievement. Overall the new guidance provides many environmental benefits and commercial opportunities for the HVAC industry should its recommendations be adopted by the construction industry as we have seen previously.

There is a role for responsible manufacturers to encourage this approach by leading the charge in growing the wider industry’s heat network knowledge. For example, Altecnic employs multiple experts and engineers who have been involved in the consultation process and delivered extensive input throughout the writing of CP1. Included within the Specification Division sales and technical team are a number of CIBSE accredited Heat Network Consultants.

We continue to offer a range of training courses across the heat network and hydronic landscape including CIBSE accredited CPDs and product training covering heat network design and hydronic balancing among others.