www.heatingandventilating.net Understanding HIU certification


Heat Interface Units (HIUs) are a crucial link between the network and the end user. For manufacturers of HIUs, TS1 references the need for product testing and certification. In practical terms, this means compliance with Building and Engineering Services Association (BESA) testing, currently the recognised benchmark for HIU performance. Although TS1 will not mandate a single route by


name, the requirement will be for any “acceptable accredited route” to certification. At present, BESA’s scheme is the one in operation, so that effectively becomes the compliance pathway. Manufacturers supplying into heat networks, and the developers and operators using their products, will therefore need to ensure they are working with certified equipment. The test covers domestic hot water


performance; space heating efficiency; heat loss and insulation characteristics; control behaviour and responsiveness; and metering and system integration outcomes. As HNTAS is phased in, HIU certification will


move from best practice to mandatory compliance. HIU manufacturers will need to supply units that have been tested to the BESA 3.1 test standard and attach the appropriate label to each unit to reflect that. Assessors will be looking for the label that clarifies the HIU has been tested to the BESA 3.1 version of the test.


A major shift for owners and operators


The biggest change will be felt by those responsible for running heat networks. For the first time, there will be independent assurance of whether a network is meeting the required standard. A third-party certificate will be needed to demonstrate that the system performs in line with its design, both at the initial stage and throughout its operational life. This creates accountability but also opportunity. Networks that are well designed and properly managed will have the certification to prove it, restoring trust among consumers and investors alike. Of course, there are challenges. Retrofitting


older systems to meet new requirements will take time, investment and expertise. We must ensure we do not discourage the continued development of heat networks, which remain a vital technology for decarbonising heat in dense urban environments. That balance will be key. The sector needs standards that push performance forward without pushing operators away.


Raising awareness and preparing for change


The publication of TS1 marks the point at which the industry must begin its transition. The HNTAS legislation was originally due to take effect on 6


Survey highlights data gaps across UK manufacturing


Star Refrigeration has published the findings of its nationwide Industrial Heat Pump Research Survey, uncovering significant opportunities for UK manufacturers to cut energy costs, reduce carbon emissions and modernise ageing heating infrastructure through heat pumps and heat recovery technologies.


H


owever, the survey also found that most UK manufacturers cannot say how much heat they use or how efficient their heating


systems are -a critical blind spot that undermines both competitiveness and decarbonisation efforts. Fewer than one in four respondents said they


could state both their annual heating energy consumption and the size of their heating plant. Where figures were reported, heating systems were operating at an average utilisation of just 24%, indicating that many sites have oversized heating infrastructure that is inefficiently operating at a fraction of its capacity. Manufacturers rely heavily on gas for heat, with


an average of 67% of demand met by fossil fuels. More than half of respondents said their heating systems were over 20 years old (See diagram), while only around a third had installed heat sub- metering.


picture of heat use and capacity, businesses struggle to build credible investment cases or fully realise the potential of renewable heating technologies.” The survey gathered responses from around 100 major manufacturing sites across multiple sectors, including food and drinks, chemicals and pharmaceuticals. Together, these industries account for a significant share of UK manufacturing output and are among the most energy intensive parts of the economy. They survey data reveals that even among established manufacturers engaged in energy and decarbonisation planning, basic data on heat use is often unavailable.


Prof. Pearson, Group Sustainable Development


Director at Star Refrigeration, said, “The survey confirms that there is huge potential for efficiency improvements that remains untapped simply because companies do not have the data they need to make informed decisions.” “Data remains the missing link. Without a clear


The findings point to a broader challenge for industrial decarbonisation. While heat accounts for a substantial share of energy use in manufacturing, it often receives less attention than electricity in corporate energy strategies and policy frameworks, potentially slowing investment and uptake of low carbon industrial heat pumps for process heat.


DOWNLOAD THE HVR APP NOW January 2026 11


INDUSTRY INSIGHT


January 2026, but this date has now been removed while Government assesses timing. Even so, delay in the legislative start does not mean delay in preparation. The technical requirements are now known,


so owners, operators, consultants, installers and manufacturers should act early to understand what they need to do to ensure compliance. MEHNA will be working closely with our members to support them through this process, sharing the latest information and helping to ensure they are ready ahead of regulation. We welcome feedback from industry stakeholders. The technical documents include mechanisms for reporting areas that may need clarification or refinement.


A positive step if we get it right


The release of TS1 is an industry milestone. It signals the shift from voluntary best practice to mandated quality assurance. Done well, this will raise standards, improve outcomes for consumers and strengthen the future of heat networks in the UK.


We must now maintain constructive engagement


across Government, expert advisors and industry to ensure that what comes next supports growth rather than limits it. Heat networks are essential to achieving our national climate goals. TS1 helps build the robust framework needed to deliver them, reliably, efficiently and at scale.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32