Modern Building Services

10 MODERN BUILDING SERVICES MAY 2021 FEATURE HEATING Improve performance and lifespan The simple and obvious solution is to design HIUs that can be installed in a position that allows easy access not just throughout the construction period but also after the apartments are occupied. Furthermore, to improve system performance and lifespan, we should design HIUs to not only comply to the BESA test but also to comply to the BSRIA BG29 2020. With conventional designs an externally accessible service cupboard could be included in the architectural layout of new buildings or retrofits, that would allow external access to HIUs. But this cupboard would take up a significant amount of valuable space within the apartment’s living space as well as adding a significant cost. That said, ceiling space, perhaps over a front door opening or at the high-level within a corridor would be largely free and potentially easily accessible externally. However, the current conventional design of HIUs doesn’t lend itself to fitting within the standard 300mm height of ceiling voids, making an external service cupboard the only option. Therefore, a new Heat Interface Unit has been designed that not only fits into a 300mm ceiling void but also complies with the new BSRIA BG29 2020 recommendation. A new design concept This new design takes advantage of the fact that a HIU is not a boiler and can be drastically reduced in size by minimising the internal pipework within the HIU and innovatively configuring the cumbersome expansion vessel. Additionally, with this new HIU design concept, the HIU does not need to be totally encased in insulation but can be strategically insulated to only encompass the vital areas such as inter connecting pipework and the heat exchangers only. This has the additional benefit of placing all electrical components and connections from the controller outside of the insulation layer. By doing this we reduce their exposure to higher than ambient temperatures which are essential to the HIU’s operation. This in turn has the additional benefit of maximising the overall components life span, which further improves the design’s green credentials (by reducing long term product consumption and landfill). “Will the traditional concept of a white box typically supplied with a first fix rail be replaced by a more practical device to better suit tomorrow’s heating and hot water needs?”