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Hybrid Water Heating, The Still the Best Choice

Adveco considers the options for adopting sustainable domestic hot water (DHW) and explains why hybrid water heating remains the best choice for commercial projects….

According to the Department for Business, Energy and Industrial Strategy (BEIS), commercial businesses account for 17% of carbon emissions, 40% of which are generated through the process of heating, cooling and lighting buildings. When demands are high, water heating has the potential to be the most energy-intensive process of all, accounting for up to 30% of daily energy demands. At Adveco our own research has shown that three-quarters of new commercial projects still opt to rely on gas, which remains a key contributor to CO₂ emissions as well as NOx which has numerous health implications.

Studies which are more “almost all electric” argue in favour of almost complete dominance of the heat pump, while the technology-open scenarios also predict large proportions of heat pumps, but also assume the use of gaseous fuels.

Just as electricity is becoming greener, via an ever-increasing share of renewable energy, so too over time will the gaseous fuels if Labour adheres to its ambitious vision for a green hydrogen revolution to support its broader Green New Deal. Staying on gas simply stacks up for a commercial business. They are familiar with the technology, and no major infrastructure changes are required, so it represents a lower capital investment, and with lower operational cost as grid-gas remains considerably cheaper than electricity. The latest generation of appliances are more efficient and are compliant out of the box with potential stage one hydrogen blends up to 20% so are a future-proof option.

This doesn’t mean commercial organisations can rest on their laurels. The impetus must be to increase sustainability to meet legally binding 2050 net zero targets, which means embracing gas but also leveraging renewables. In other words, adopting a hybrid water heating route to supply a building’s demands.

Hybrid water heating systems are particularly relevant to buildings in which there is already a gas connection as they will require two heat generators and two energy connections, one of which being an environmental heat source. This leads to a higher complexity of the plant, requiring more effort and expertise from the system designer, supplier and installer which leads to higher CAPEX costs. It is typically estimated that the purchase and installation of a hybrid water heating system compared to a pure condensing heating system is going to drive initial costs up by approximately 50 to 60%. So, what are the advantages that outweigh these initial costs? 

For older commercial properties where a new heating system is required, but wider renovation is either not feasible or required, a hybrid water heating system with, for example, a heat pump, can be used as the pre-heat to supplement pre-existing fossil-based heating systems.  This helps to save costs as existing boilers can continue to be operated on the current installed heat distribution, heat transfer and flue systems while the heat pump can benefit from an advantageous coefficient of performance (COP) in the right conditions and setpoints.

A hybrid heat pump/gas boiler system can reduce the maximum power consumption of a system by smartly balancing the heat generators for greater efficiencies and lower operational costs whilst guaranteeing high system temperatures to ensure the comfort of those still living or working in the building during refurbishment work. If the hybrid system is also equipped with a buffer tank and a domestic hot water tank the heat pump can achieve a high proportion of cover for space heating and DHW heating increasing the profitability of the system.

A hybrid water heating system cannot only be controlled cost-effectively, it can also be optimised for CO₂ emissions by selecting the optimal (ecological) heat generator whenever possible via an energy management system that incorporates smart metering. With load management, the smart balancing of heat pump and condensing boiler operation, it not only becomes possible to address the lifetime cost of operating a system but can help with the support of grid capacity, stabilisation of reserve capacities and potentially reduce the need for grid expansion.  Should the building envelope subsequently be renovated, the required heating load decreases and the existing gas boiler can take on less of the annual heating work or eventually could be put out of operation.

Hybrid water heating systems offer a fast and cost-effective means for addressing ageing and environmentally unfriendly heating systems, improving operations, delivering on corporate social responsibility and legal sustainability reporting. Due to the increased complexity ensure you communicate with an experienced design authority such as Adveco, which can walk you through system assessment, design and provision of optimal appliances, whether gas, heat pumps or solar thermal to deliver the most effective hybrid systems at the best cost.