IN FOCUS Gas Water Heating and Sustainability For Commercial Buildings W


ith increasing concerns over global warming and the drive toward net zero building operations it may sound counterproductive to stay on gas water heating as a sustainable strategy. While carbon savings are not optimal, this remains the most cost-effective choice


in terms of both capital and operational investments for existing buildings. The latest generation of gas water heaters are highly efficient, with burner, heat exchanger and flue gas management technology maximising energy use for lower emissions of CO₂ and NOx, and they also offer a stratagem should the UK opt to embrace a national green gas grid. Expectations for a national hydrogen network, should it proceed, would see a full transition in the 2040s, which aligns with end-of-life decisions for new appliances installed now. The current generation of gas water heaters also offers an out-of-the-box capability to use 20% hydrogen blends, which is likely the first stage of regional hydrogen transition. So, the technology provides a bridge to next-generation sustainable hot water in commercial buildings. When selecting a gas water heater for your project there are always key considerations around


installation, such as access, space, pipework and flueing, but the real defining challenge is addressing water quality at site. The UK presents a varied picture of soft (>100ppm of dissolved calcium and magnesium) to hard water (<280ppm) areas. As water in a commercial hot water system heats up, the solubility of calcium and magnesium bicarbonates decreases, triggering limescale formation in hard water areas which can wreak havoc on the water heater’s efficiency, longevity, and overall performance countering heating and sustainability strategies. Optimised system design which minimises areas of low flow and stagnation zones and regular system


maintenance, including flushing and cleaning and treating with water softeners is crucial in helping prevent excessive scale accumulation. Cleaning and treatment is aided by the use of glass-lined carbon steel water heaters and tanks such as the BFC and Innovo models offered by Adveco. With dual glass lining treatment which bonds to the steel cylinder and forms a smooth protective surface in contact with the water they are lower in cost to purchase, easy to clean and, given the right conditions, provided resistance to attack from most chemicals and corrosive materials. Not all glass-lining processes though are equal, with some being prone to developing microscopic


cracks leading to small areas of the steel cylinder shell being exposed to the water. This is less of an issue in hard water areas, but where the water is softer there is an opportunity for corrosion to rapidly take hold leading to critical failure. Galvanic corrosion in water heaters and tanks is typically managed using cathodic anodes made of magnesium or powered anodes of titanium. However, in many soft water areas, a powered anode may still not have a protective effect, since the conductivity required of the water by the anode is too poor. For this reason, commercial hot water systems in Scotland, south-west and north-west of England


and the west of Wales where water is particularly soft will typically need to employ a stainless-steel appliance such Adveco’s AD and ADplus ranges of compact condensing gas water heaters. Better able to stand up to both waterside and combustion-side assaults, these stainless-steel water heaters are less susceptible to corrosion due to a protective oxide barrier on the waterside that naturally helps prevents corrosion, even when temperatures increase. Able to withstand higher temperature water (in excess of 80°C) than glass-lined appliances, stainless-steel also lends itself to solar thermal applications which can achieve high, consistent water temperature in the summer months.


By adding solar thermal to a gas-fired system you unlock a hybrid approach which will blend improved


carbon savings with lower operational costs. Used to generate preheat this approach maximises the efficiency of the technologies involved, creating water temperatures of at least 50°C. Not enough alone for safe legionella-free operation (especially when days are shorter), but when combined with a gas-fired primary heat source, it can be used to raise final temperatures to a necessary 65°C as well as meet peak demands and exceptional requirements for hot water. A true renewable and intrinsically safe to operate, solar thermal technology is designed to use gravity feed, aided by a small water pump for minimal operational energy demands and robust operation. Using far less space for collectors than photo-voltaic solar systems, solar thermal is the optimal low-carbon technology for water heating, capable of offsetting at least 30% of annual system energy demands. As well as active carbon reduction, current cost savings from solar thermal installation mean the technology offers one of the fastest returns on investment for sustainable hot water in commercial environments. Adveco has current stock of glass-lined and stainless steel gas water heaters, as well as the UK’s widest range of cylinders, plus solar thermal collectors and protective drain back systems and can support orders now for summer project deliveries.


www.adveco.co Dehumidification Webinar CIBSE CPD F


ollowing the success of Humidity Solutions first CIBSE-approved CPD webinar on humidification in March, their humidity control experts are back with another insightful CPD session, this time focusing on dehumidification.


Join Freddie Kar and Arian Rao on Thursday 12th June at 2pm to deepen your understanding of dehumidification systems and earn one hour of CIBSE CPD points. Don’t miss this opportunity to boost your knowledge and stay up to date with best practices in dehumidification.


What's covered?


✔ What is Relative Humidity? ✔ Psychrometric Chart Calculations ✔ The Importance of Humidity Control ✔ Dehumidifier Sizing ✔ Dehumidifier Types ✔ Design Considerations ✔ Questions & Answers


Hamworthy Heating provides Cambridge primary school with new Tyneham heat pump cascade installation


T


wo Tyneham 290HT 27kW air source heat pumps from Hamworthy Heating – a trusted British manufacturer and supplier of commercial heating and hot water products – have


been installed in cascade for underfloor heating in a new extension at a primary school in Cambridge. To accurately meet the heating requirements of the new school


extension and ensure an even distribution of heat, the new system from Hamworthy Heating includes two 290HT 27kW Tyneham heat pumps with natural refrigerant, configured in a hydraulic cascade set up. The heat pumps are connected to a 500L buffer cylinder, which also features an electrical heating element, controlled by a BMS. The buffer connections, Exogel anti-freeze valves and degassers were also supplied by Hamworthy Heating. This cascade arrangement allows for the heat capacity to be equally distributed according to the specific heating demands of the new school building. Rather than rely on a larger single heat pump that could run inefficiently at partial load, the new


cascade set up enables the units, which have inverter controlled compressors, to adjust their capacities as needed which will enable the school to achieve a more accurate match to its actual heating demand and optimise performance. Additionally, as the new system can adjust to keep the heat pumps operating at their most efficient


state, cycling of heat pumps and unnecessary energy consumption is avoided. The two new Tyneham 290 HT installation also provides the school with increased protection against


breakdowns. Unlike a single heat pump installation, which can result in complete downtime, the new system now supplies the new building with uninterrupted heating. Furthermore, as the workload is shared across two Tyneham heat pumps, stress and wear on individual components is significantly reduced. Following a previously successful collaboration with Hamworthy Heating on the schools existing


heating system, Sotham Engineering were keen to stick with a brand they could trust on the second phase of its project. Ricky Harris, Sotham Engineering Services Ltd comments, “We choose Tyneham heat pumps due to


their overall performance and efficiency. Having collaborated with Hamworthy during the first stage of the project, we found them easy to work with and always available to provide support and assistance”. Building on the success of its popular Tyneham heat pump range, the new 290HT heat pump utilising


natural refrigerant offers a co-efficiency of performance (COP) of up to 4.94 for optimum efficiency. Quiet in operation, with noise levels as low as 64db(A), the latest 290HT heat pump range is available


in five outputs from 15kW through to 50kW and can be cascaded to achieve higher outputs and can be combined with alternative Hamworthy Heating products to achieve a low-carbon hybrid heating system. Following a successful installation, the new extension now benefits from a reliable and efficient heat pump system that will help the school to reduce its carbon footprint and lower operational costs.


register.gotowebinar.com Read the latest at: www.bsee.co.uk hamworthy-heating.com BUILDING SERVICES & ENVIRONMENTAL ENGINEER JUNE 2025 31


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