Tag Archive for: ARDENT electric boiler

Extra Gains For Net Zero Restaurants

Commercial hot water specialist Adveco is working in partnership with a global restaurant brand to support the rollout of net zero restaurants demonstrating low emission innovations throughout its chain of UK drive-through and high street franchises.

Through its programme of live metering, Adveco demonstrated that servicing domestic hot water (DHW) water demands of between 1200-1500 litres per day could equate to as much as 20% of total energy usage within the organisation’s target net zero restaurants. A recent refurbishment of a restaurant in the King’s Cross area of London provided an opportunity to address the emissions generated by this provision of hot water for the restaurant. In addition, working within existing building limits means applications need to maximise often limited plant room space. This was especially true of this central London location which also faced problems with limescale due to the hardness of the water supply.

Working to an all-electric specification, Adveco designed an application that would harness a 9kW FPi32 air source heat pump (ASHP) for preheat and supplying additional top-up heat with an ARDENT P 12kW electric boiler. These would supply thermal energy to a mains water-fed compact SST500 stainless steel twin-coil indirect cylinder.

By combining ASHP and an electric boiler Adveco can address many of the complexities associated with integrating ASHPs into existing buildings. This combination enables systems to be sized down, by as much as half in terms of ASHP requirements delivering immediate capital savings as electric boilers are far less expensive compared to an equivalent heat pump. You also immediately reduce the physical size of the system, embodied carbon and demand from the electric supply. Additionally, the system retains redundancy should there ever be a failure.

Balancing a hybrid electric system is key to ensuring efficient operation. Adveco supplied the controls to assure the water heating remains consistent, optimising the ASHP preheat and top-up from the boiler to reduce energy demands and the building’s emissions.

The other advantage of incorporating the ARDENT electric boiler was that it heats water using immersion heaters located in a small tank within the boiler housing rather than directly installed into the hot water tank. This creates a sealed ‘primary’ loop to the indirect coil in the SST500 cylinder. The electric boiler heats the same water continuously so there is only a small, finite amount of scale in the system which will not damage the elements. The heat exchanger in the cylinder is a large coil operating at a relatively low (80°C) temperature eliminating the common problems of destructive limescale build-up seen in direct immersion electric heating.

The electric boiler operates at the same efficiency as an electric immersion heater (100%) and so the only overall difference in system efficiency is the minimal pump electrical consumption and a negligible amount of heat loss in the pipework

Although the system takes up a little more space than an all-in-one electric cylinder, it has more versatility. It requires less clearance for the cylinder, so it was compact enough to fit into the extremely limited space allowed for plant in the restaurant. With the cylinder forming significantly less scale, the restaurant has gained from vastly improved reliability while reducing maintenance demands, for both operational and maintenance savings on top of crucial emission reductions.

Visit the Adveco restaurant resource for more guidance on delivering low carbon and renewables to help achieve net zero restaurants by 2050, or read our free handbook. 

Building Sustainability Into Commercial DHW

For more than fifty years, Adveco has been a leading innovator providing domestic hot water (DHW) applications for commercial-scale projects across the UK. Today its focus is shifting to encompass a blend of traditional and new, more renewable technologies in the form of solar thermal and especially heat pumps building sustainability into commercial DHW systems.

With a predicted one-third rise in non-domestic floor space by 2050, much of the current focus resides on new builds, but this still leaves more than 1.6 million pre-existing non-domestic buildings in England and Wales, generating almost one-fifth of the UK’s carbon emissions, needing expert, practical support.

Air source heat pumps (ASHP) have become the poster child technology for the government’s net zero strategy and therefore a core tool for building sustainability into commercial DHW systems.  The advantage of ASHPs is that, with performance greater than 100%, they can extract additional energy from outside of the building’s metered systems delivering significant carbon savings. For a commercial DHW system, it is recommended that a working water temperature from the ASHP, such as Adveco’s FPi32 or L70, must be at least 55°C. This is certainly attainable from current generation ASHPs when deployed in a hybrid approach. This uses the ASHP as preheat and combines it with either gas-fired or more preferably an electric top-up to achieve the required hot water temperature. This is where the additional system complexity and cost can creep in. But by correctly balancing a system through a mix of physical spacing in the vessel and system monitoring with dedicated controls, as developed for the Adveco FUSION, the system no longer fights itself, working seamlessly to deliver the highest operational efficiencies

In line with the European Commission’s proposal for a tightening of F-Gas regulations, development work continues at pace to support the introduction of R290, or propane as it is more commonly known. This refrigerant offers a coefficient of performance (COP) that enables working flow temperatures from an ASHP of up to 75°C and potentially much higher. This means future commercial systems can be less complex, without the need for additional electric immersion for high-temperature top-up and flushing for legionella protection. That said, immersions remain perfectly suitable for low-demand backup applications in boiler-fed indirect cylinders, ensuring business-critical DHW demands are met.

What we have seen more recently though is a shift in use, where immersions are used ‘directly’ in high-demand commercial applications as the primary heat source. An electric immersion heater has a high heat intensity compared to gas or indirect and, when coupled with high operating temperatures and hard water will increase the rate of scale formation which, over time, will cause the element to rupture.

In response, protecting a system from limescale is often only addressed by a vigorous cleaning regime. This method has a cost and downtime associated with it that is not acceptable for many commercial buildings.  For this reason, minimisation of scale formation with a water softener or a scale inhibitor may be adopted, but for many sites neither provides a satisfactory response because of space, maintenance, downtime, or cost.  A better option for these sites would be to replace the immersion heaters with a low-scale forming hot water system.

The new Adveco ARDENT electric boiler range provides a proven and cost-effective answer. Electric boilers still utilise immersion heaters located in a small tank heat exchanger within the boiler housing. This electric boiler supplies a sealed ‘primary’ loop to an indirect coil in the cylinder. The electric boiler heats the same water continuously so there is only a finite amount of scale in the system which will not damage the elements. The heat exchanger in the cylinder is a large coil operating at relatively low temperatures. Adveco’s extensive experience with indirect coil use in the UK has shown that scale is not a significant problem in these systems. The electric boiler operates at the same efficiency as an electric immersion heater (100%) so the only overall difference in system efficiency is the minimal pump electrical consumption and a small amount of heat loss in the pipework.

An electric boiler hot water system will take up a little more space than an all-in-one electric cylinder, but it has more versatility and requires less clearance for the cylinder. Similarly priced to an immersion heater, an electric boiler-based system will cost slightly more due to the small amount of additional installation work. But with virtually no maintenance and the cylinder forming significantly less scale, vastly improving reliability, the operational and maintenance savings will offset these additional capital costs. The electric boiler additionally offers a level of redundancy that is not achieved with a single immersion heater.

As the limitation on new gas grid connections for heating systems becomes effective this year, it will become critical for system longevity to recognise the new challenges electric-only presents over more familiar gas-based applications. If a business already uses gas, then it can still upgrade to new gas appliances until 2035, with 100% hydrogen-ready options extending that window well into the 2040s based on current appliance lifespan.

Adveco continues to support the refurbishment of existing buildings, recently extending its ranges of direct-fired condensing water heaters – the AD and the ADplus. Both ranges provide a compact, floor-standing design that is easy to introduce into an existing plant room to provide high-demand semi-instantaneous and instantaneous hot water applications.  Improved combustion efficiency means the burner requires less gas, delivering up to 30% savings in fuel consumption, making it more cost-effective, while reducing emissions.  For smaller on-demand needs, ADplus heats only what is necessary, with no ignition for smaller withdrawals providing considerable additional energy savings. Both AD and ADplus as a result exhibit ultra-low NOX (Class 6 appliance at 27 mg/kWh) and CO emissions (19ppm). With the government already committed to enabling the blending of hydrogen in the gas grid, it is also worth noting that these latest generation direct-fired condensing water heaters will already support the initial 20% hydrogen/natural gas blend.

Together, these technologies offer actual development arcs right now for existing commercial properties that are currently on gas, or new builds seeking to embrace low or no emission choices building sustainability into commercial DHW systems for more environmentally friendly operations that will help organisations achieve net zero by 2050.