Time for best practice

Pete Mills, Commercial Technical Operations Manager for Bosch Commercial & Industrial dissects the latest on heat networks’ future.

Decarbonising the energy used to heat our homes and buildings remains a key target for Government policy, following the recent 10-point plan announcements from the Prime Minister. The ongoing COVID crisis may have some short-term benefit of lower emissions from transport, but we will have to see if the opposite has been true for heating, with so many of us now working from home. This highlights the importance of emissions from heating, if work environments change to a pattern of far more home based workers.

Although many of the highlights of the 10-point plan were focussed on the important benefits that hydrogen could bring to tackling this problem, heat networks remain a key pathway to decarbonising homes in dense urban areas. They are the only technology that can really make use of waste heat at the scale we will need to reduce primary energy use. Heat networks are also the most flexible heat delivery system when it comes to utilising different heat sources.

A pivotal moment

2021 is looking to be an important year in the development of heat networks in the UK. We are midway through the consultation process looking at overall regulation of the industry, under the Heat Networks: building a market framework. This will be a very significant move as the industry looks to address some of the issues around service levels and heat network performance that have been seen in a relatively small number of schemes. Regulation should raise the industry to a similar level as other utilities to ensure consumer protections are hard wired in from the start. The recent publication from Citizen Advice has once again highlighted the immediate need to address, in particular, service levels and transparency to consumers.

The learning curve

There has been a lot of learning and experienced gained about how heat networks perform under UK requirements. Much of this knowledge has been captured in the update of CIBSE CP1(2020), Heat Networks a Code of Practice for the UK, which was released early in the new year. The code of practice was first released back in 2015 and has done a great deal to improve the performance and delivery of UK heat networks. CP1(2020) is set to have a similar uplift for the industry, as it sets out to make use of the code more verifiable, transparent and consistent. Verifying use of the code was a key driver for the revision of CP1 as it links to SAP and is now set to offer technical compliance as part of a regulated industry when that comes.

CP1, as CIBSE’s first code of practice document, has always sat somewhere between being a process to follow for realising good outcomes for heat networks and a technical guide. From the start, there was a clear desire not to over dictate towards any particular technical solution, but rather to allow flexibility and innovation to drive the best solution, within clear targets for outcomes. This approach is maintained, but is strengthened with both additional technical guidance and tighter processes. Alongside the main document is a spreadsheet aimed at logging the evidence at key stages of planning, design, installation and commissioning. Altogether, this information will form an evidence pack for the client to demonstrate the schemes compliance.

There is now far greater reference to the clients responsibilities within the process, although recognition that the day-to-day involvement is more likely to come from a qualified heat network specialist, working on behalf of the client. The improved demarcation of roles and responsibilities that CP1 now contains should act as a reference for the legal agreements that are often necessary for the larger schemes.

Commissioning clarity

Commissioning is often a make or break stage of a heat network scheme and this has been highlighted by CP1(2020). No matter how well designed and installed a heat network may be, if it is not commissioned correctly it will never perform as intended. The link up and flow of information from the design team, to installation team and on to the commissioning team is vital. Here again the accompanying spreadsheet should help to record the key information needed.

The relevant sections of the code referring to commissioning have been completely revised and this is partly due to the requirement for acceptance testing. Acceptance testing should be a game changer for improving better outcomes for end users and operators of a scheme. It involves independent verification in individual dwellings that the design performance is being met. Annex B of the new document sets out example procedures to follow, which should form the basis of these test. Time must be allocated with the overall program of works to ensure that this stage can be met, as without it, the code is not being followed and the necessary evidence will not be available.

Overall CP1(2020) represents another big step forward for the industry and is something all involved should embrace and welcome. Ultimately, the health and maturity of the industry will be gauged on customer satisfaction and carbon savings, things that should always be at the forefront as we look to make our homes fit for net zero.