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.

Heat Pumps – The Cost Of Reducing Emissions

With the government strongly advocating the use of heat pumps as a method of delivering net zero targets for commercial properties, we have noticed the trend for broad statements implying that while cutting emissions, heat pumps also reduce the energy costs for a building. It’s just not that simple argues Adveco’s UK sales manager Greg Brushett. So what is the cost of reducing emissions?

We strongly support the advantages of heat pumps as part of an all-electric or hybrid domestic hot water (DHW) system to achieve carbon savings. With DHW equating to as much as 20% of the total energy demand for domestic buildings and anywhere from 10-70% for commercial properties, it is important to clarify how heat pumps are being employed in a building’s system.

With a gas-fired system, you can achieve a safe DHW storage temperature without a significant impact on the overall efficiency but with a heat pump you need to either force the compressor to work very hard, which will reduce the Coefficient of Performance (COP) or, in a lot of cases, use the heat pump to partially heat the hot water and then use an immersion heater  – which has a COP of just 1.0 and therefore higher energy costs – to do the remaining work. If you are willing to accept this extra cost, working flow temperatures of 50- 55°C from the heat pump to an electric or hybrid DHW system are more than achievable year-round in the UK, and emissions will be dramatically reduced.

However, broad statements such as “heat pumps reduce costs” or “gas boilers remain more economic to run than heat pumps” are inherently misleading.

A heat pump can supply a properly insulated building’s heating system completely, and if designed well enough, can achieve a COP of 3.0, or slightly more, giving a similar yearly cost (within 10%) to that of a gas-fired heating system This would also be more attainable with the recent change in gas and electricity prices.

The same is not true of a hot water system. Following initial modelling and analysing reports from live systems a hot water hybrid system that achieves 50°C with an overall COP of 2.76 and uses an immersion heater to top up to 60°C has an overall efficiency of 2.4 based on the weighted average. Using these results, the running costs of the system are seen to be significantly higher than a gas system. However, the argument does demonstrate that incorporating heat pumps into an electric-only DHW system shows considerable savings over a COP of 1.0. Partnering this with other technologies such as solar thermal will only increase the benefits.

Benefits or efficiency?

Making the right choice between heat pump or gas depends on what an organisation is intending – whether seeking active emission reduction now, or, if already on gas, securing cost-saving operation until sustainable technology further matures, and costs fall.

Heat pumps can give incredible carbon emission savings for existing buildings, but as a way to reduce energy costs, replacing a gas-fired boiler/water heater with a heat pump doesn’t always add up. Commercial properties have unique demands, especially for DHW, making better application design and installation all the more important when it comes to specifying the right technology. Be wary of claims being made regarding the application of heat pumps, especially for the provision of DHW when it comes to calculating the cost of reducing emissions.

Adveco ADplus Instantaneous Commercial Water Heaters

  • A range of three compact floor-standing commercial instantaneous gas-fired condensing water heaters with built-in storage tank
  • Perfect for all water qualities with a 5-year warranty on burner and heat exchangers

Commercial hot water specialist Adveco, announces the Adveco ADplus range of high-power gas-fired condensing water heaters featuring an integrated 120-litre stainless steel water storage tank for instantaneous continuous and on-demand domestic hot water (DHW). The ADplus is available in three variants – 70 kW, 115 kW and 140 kW rated heat output.

“Designed to provide a compact, high capacity and reliable method for delivering instantaneous hot water to a commercial building, ADplus is a tough all-rounder,” said Bill Sinclair, technical director, Adveco. “It is perfect for a wide range of applications – from small instant demands to large-scale continuous DHW needs. With minimal NOX and CO emissions, the ADplus range is an eco-friendly way to serve your building’s DHW system. The rugged construction, supported by Adveco’s in-house warranty engineers, provides real peace of mind for your investment.”

The 115 kW and 140 kW ADplus variants offer two high-quality heat exchangers. Constructed from corrosive-resistant continuous run titanium-stabilised stainless steel, these provide balanced highly efficient operation and built-in redundancy. Heat is provided by the patented Fecralloy premix burner fed by a consistent balanced air/gas ratio at each point of turndown. The high modulation ratio results in high combustion efficiency with ultra-low NOX and CO emissions. A built-in flue back preventer on the combustion circuit prevents possible flue gas recirculation between different exchangers.

The tough, stainless steel 120-litre storage tank is provided with electronic anodic protection and high-quality polyurethane thermal insulation. This enables the ADplus to serve as a semi-storage system, providing always available and instantaneous supply with quick recovery times for continuous provision of DHW. For on-demand needs, ADplus heats what is necessary, with no ignition for smaller withdrawals providing considerable energy savings. When heat is required, the condensing technology provides up to 30% savings in fuel consumption. To reduce acidity build-up caused by the condensing process, the ADplus is equipped with a condensate acidity neutraliser, specifically sized to restore tolerable pH values. With the anti-corrosive construction, ADplus can be used with soft and softened water. For harder water, the recirculating pump regulates the correct water flow according to inlet water hardness helping to prevent the formation of limescale on the heat exchanger surface, ensuring high performance throughout its life cycle.

The extremely compact Adveco ADplus is designed to pass through a standard 65cm wide door for trouble-free installation and offers front access to all inner components for quick, easy maintenance. The integrated cascade controller supports full temperature control and self-check maintenance functions for up to 8 units. The controller accommodates 0-10 input, MODBUS communication, and alarm output for seamless BMS integration.

Additional Information

  • High capacity DHW production
  • Compact floor-standing arrangement
  • High-efficiency pre-mix burner with a five-year warranty
  • Extremely high-quality AISI 316Ti heat exchangers with a five-year warranty
  • Ultra-low NOX emissions, class 6 appliance at 27 mg/kWh
  • CO emissions 19ppm
  • High maximum run pressure up to 11 bar
  • Flue gas non-return valve for overpressure cascade flue systems
  • Standard flue systems using low-cost 110mm diameter PP
  • Available using natural gas or LPG

Read more about the Adveco ADplus instantaneous commercial water heater range 

Keeping Hot Water Flowing

Keeping hot water flowing is critical in the commercial sector, where domestic hot water (DHW) appliances will be subjected to extremely hostile conditions, with high temperatures, thermal stress and flue gas condensate on the combustion side and oxygen, minerals and chemical attacks leading to potential corrosion on the waterside. Given this harsh daily treatment, regular servicing and maintenance are key if business-critical service is to be observed. Ensuring consistent operations and prolonging the life of a commercial hot water and heating system should therefore be a key factor when specifying and costing out these business-critical systems.

Once an application is sized correctly and installed, that maintenance process begins with commissioning. This choice falls to the customer, but Adveco advises that it should be engaged to commission its own appliances. This ensures product warranty commences from the date of commissioning, rather than the date of delivery which may be months before a system eventually goes live. If not commissioned by Adveco, it will also fall to the customer to fault find, order the new part and return the faulty part, which can be a painful, time-consuming process for any facility manager who is already time-poor.

Keeping hot water flowing to support consistent operations, we specialise in both commissioning and proactive warranty service to the manufacturer’s recommendations. This is crucial for the consistent and efficient operation of an appliance which can be affected by a range of environmental factors, water condition most notably, but air quality can also harm operation. The UK is broadly split between hard and soft water conditions. In naturally soft water conditions, despite the use of sacrificial anodes, glass-lined vessels can rapidly succumb to critical corrosive damage, making stainless steel the optimal choice, with longevity countering higher purchase costs. Commercial glass-lined steel water heaters and tanks are usually the more cost-attractive proposition in the UK, especially in harder water areas, where, given the right conditions, they are generally resistant to attack from most chemicals and less-corrosive materials. However, the deposition of calcium carbonate, or scale, found in harder water remains a key issue, whether opting for glass-lined or stainless steel vessels.

The latest generation of water heaters may incorporate recirculation pumps to balance the flow of water through the appliance’s heat exchanger. That balance is critical as higher flows can reduce calcification, but it can also lead to corrosion where that flow is interrupted or broken. This is why internal forms should default to curves within the design to provide consistent, unbroken flows.

In typical operation in harder waters, in our experience, it is almost impossible to completely avoid the build-up of scale. Magnets simply do not work properly, so the use of an inhibitor fluid is critical alongside regular annual servicing. This can be of a representative number of appliances on a premise, with conditions that reduce or extend that service period. Low levels of scale may allow for units to be serviced in alternate years for example reducing costs. That annual service must however be thorough.

Too many times an ‘annual service’ will be a quick test with an analyser and issue of a landlord’s certificate. Such activity is relatively low cost, as it avoids the purchase of a service kit, but is ultimately a false economy. It will miss the early onset of calcification and means the water heater or boiler is more likely to suffer early, terminal blockage. For a thorough annual service, we would advocate appliances be fully drained, visually examined and any scale be removed. The process involves disassembly which requires the replacement of rubbers and gaskets, hence the requirement to purchase a service kit. Though more costly, such full services are substantially cheaper than the cost of replacing blocked heat exchangers, burners and even the entire appliance.

If scale build-up is not addressed, then within five years any descaler fluid introduced will simply wash over the surface, which will also easily resist the most concerted of hammer blows. At this stage, the descaler will also not pass through the heat exchanger, requiring its complete replacement. This is seen when servicing or preventative maintenance has been avoided or forgotten, at which point the manufacturer’s warranty will be void.

Annual monitoring of the inhibitor system used for boilers is also key, especially if heating facilities have been refurbished within a building. It is not uncommon to see boilers damaged after radiators are replaced, and new water introduced into the system without replacing lost inhibitor fluid. Monitoring and replacement as part of the annual service activity will again protect the heat exchangers.

The other key failure point is the burner in gas-fired appliances. Condensing boilers and water heaters will draw air from the plant room and if that is dusty, it will be sucked in, reducing the efficiency. If not cleaned regularly, the burner will soot up and eventually become blocked often requiring full replacement at some cost. Even if located in an open space, or exterior to the building the burner should be thoroughly inspected. Nearby building works can cause high levels of dust, and in dense urban areas, pollutants from vehicles can also be drawn into the appliance causing build-up of dirt on the burner.

Serviced thoroughly and regularly, commercial water heaters and boilers should have an efficient operational lifespan of at least ten years (depending on location), and we do see appliances still operating for twice that length of time. The caveat in these cases though is that the overall efficiency of legacy units operating for more than 10 years will be far lower than current generations of appliances and will almost certainly fail to meet current ERP regulations on emissions introduced in 2018 for new water heaters and boilers. So continued maintenance of such units would not only be a false economy in terms of running costs but will certainly not be contributing to any efforts to introduce better sustainability in a building.

In short, failure to descale, flush sediment, clean burners, check anodes or test for corrosion will reduce the operational longevity of any appliance, but also severely impact the efficient operation. That has negative implications on operational costs and unwarranted capital implications if there is a catastrophic failure. Under such conditions, this will almost certainly invalidate any manufacturer warranty that exists. Reactive service providers will only check gas pressures and overall condition, they will then wait for breakdowns and call outs.  Only by keeping hot water flowing through proactive servicing can you ensure any costly downtime of business-critical hot water is absolutely minimised.

Keeping hot water flowing. Visit our warranty service page or contact us to arrange for your service.

Adveco AD: Providing Continuity of Service in Soft Water Conditions

• The Adveco AD range of compact commercial semi-instantaneous gas condensing water heaters
• Perfect for applications requiring direct contact with soft and softened water
• Highly efficient modular design offers continuity of service in one appliance.  Or can be deployed as an on-gas system backup for larger-scale heat pumps projects

Commercial hot water specialist Adveco, presents the new AD range for 2022. This latest generation of sleekly designed, modulating commercial floor-standing gas condensing water heaters is conceived to be used with a buffer for high demand semi-instantaneous hot water applications in sports & leisure centres, hotels, spas, schools, stadia, and large commercial buildings.

With each water heater composed of one to four 70 kW heat exchangers, the Adveco AD range offers appliances from 70kW up to 280 kW. This approach optimises the supplied output (up to 160 litres/minute) ensuring maximum efficiency when providing DHW. Models with multiple integrated heat exchangers offer load balancing for optimal long-life operation and inbuilt redundancy guaranteeing continuity of service.

Bill Sinclair, technical director, Adveco said,” As well as the continuity of service seen in individual units, the AD is perfect for integrating into large scale heat pumps systems seen in hotels and hospitality. So long as there is an existing gas connection, AD can be used to provide a cost-effective and easy to accommodate back-up for assured continuity of business-critical water heating.”

Tough and efficient, AD water heaters are all equipped with premix burners made of Fecralloy metal fibre for large modulation range with excellent functionality at extremely high temperatures. Using a premix burner ensures the AD requires less gas, making it more cost-effective, plus reducing harmful NOX and CO emissions.

The titanium-stabilised stainless-steel construction of the AD range’s heat exchangers is the perfect response to counter corrosion typically seen in high-pressure circuits in soft, or softened water applications. The heat exchangers work with an electronically controlled variable stainless steel modulating recirculating pump and two-way motorized valves to ensure a perfect balance between water flow and supplied output.

The AD range can also be configured to operate in a cascade of up to eight water heaters. The AD’s controller provides full temperature control and self-check maintenance functions. The controller also accommodates 0-10 input, MODBUS communication, and alarm output for seamless system integration.

Compact, lightweight yet still powerful, the Adveco AD’s patented space-saving design makes it equally applicable to both new projects or renovation work where a lack of space would traditionally stall or quickly drive up costs of a project.

Additional information
• Five-year warranty on AISI 316Ti heat exchangers with
• 10-year warranty on pre-mix burner
• Compact floor standing arrangement: AD 70T & AD140T H1180xW600xD945mm / AD210T & AD280T M1880xW600xD896mm
• High maximum run pressure up to 11 bar
• Low emissions, built with Class 6 technology for NOₓ at 27 mg/kWh GCV
• Available for natural gas or LPG
• Acid condensate neutraliser included
• Ideal for soft water applications. Hard water areas over 150ppm require use of a water softener down to 100ppm.
• Supports standard flue systems using low cost 110-160 mm diameter PP

Installing commercial heat pumps – what to look for

Adveco’s FPi32 commercial heat pumps range are not only a renewable source of hot water with low running costs but are one of the easiest to fit when it comes to installing commercial heat pumps.

With the government-led push to replace ageing commercial hot water systems with new, more environmentally friendlier technologies, the demands for heat pump based applications is expected to soar in the coming decade. One of the key concerns raised by the HVAC industry is the availability of trained installers capable of working with heat pumps. While the number of commercial installations may be superseded by domestic sites, their complexity means installers will increasingly be in demand. To prevent costly hold-ups, projects incorporating ASHPs should take into account how difficult or easy installation of commercial heat pumps might be.

The FPi32’s compact monobloc design, with a built-in circulation pump and plate heat exchanger, allows for an easy installation for a multitude of work areas. This includes both indoors and outdoors. They can be installed in small unused spaces, mounted on exterior walls or flat roofs of the site. Installed on flat roofs or mounted onto GRP plant rooms.

An FPi32 installation also requires few ancillaries (strainer, expansion vessel and pressure relief valve) to enable its operation as part of a hot water system. This also helps to keep system purchase costs lower as well.

Another advantage of installing commercial heat pumps, such as these compact FPi32 units, is that less construction work and time is needed to fit them. They can be up and running quicker, providing working flows of hot water sooner than other units currently in the commercial market. They can then efficiently and effectively sustain the necessary working temperature of 50°C required to provide preheat as part of a hybrid all-electric system in new build projects.

Ease of installation goes hand in hand with significantly reduced maintenance costs.

The design of these FPi32 units incorporates effective frost protection, enhancing the option to install outdoors. The FPi32 range is equipped with a 1.5-metre ‘trace heating cable’ as standard, which is there to protect the pipework between the heat pump and the building from frost conditions. This ‘trace heating’ via the mechanical thermostat is always available when the heat pump has power. This guarantees protection against frosty conditions when needed, regardless of whether the heat pump is operating.

This monobloc design simply requires regular cleaning of the coil and water filter in terms of regular maintenance. The internal parts are easily accessible for all maintenance needs. A refrigerant circuit high-pressure gauge is cleverly positioned so that this can be read clearly and easily through the external cover to monitor the pressure and indicate whether a leak may or may not have occurred. Access to the internal parts, in the need of any replacements, can be achieved without long evaluation wait times. For example, if the replacement of non-return valves on sensors and switches is required then the quick replacement time is advantageous, reducing the amount of “down time” on the unit. All of which equates to an extremely work effective and reliable unit for your commercial needs. This demonstrates that, once supplied by Adveco, installing commercial heat pumps is easy and is also a more forward-thinking way for a greener environmental contribution. Reliability and efficiency equal greater sustainability, as well as keeping those costs lower all round.

We would argue that under the right circumstances, installing commercial heat pumps can be a relatively straightforward and successful way to introduce greater sustainability into the hot water system for new build projects. The FPi32 heat pump range represents a win-win, ticking all the boxes for a sensible purchase, offering a simpler, more efficient option for installing commercial heat pumps in a variety of ways. Once fitted, required maintenance is quick and easy, all whilst helping contribute to a project’s green credentials.

Learn more about renewables.

Adveco SSB-E Lower Carbon Electric Water Heating

The Adveco SSB-E is a range of tough, stainless steel electric water heaters for commercial DHW applications. Based on the SSB buffer vessel, the SSB-E, through the addition of a specialised single or double-mounting flanges integrates electric immersions becoming a full-fledged electric water heater. SSB-E is available from 200 to 2500 litre capacity variants with up to 84 kW of heating for larger scale commercial hot water demands.

Heating capacity is achieved with up to four primary three to 12 kW immersion heaters. The addition of an immersion of three to 36 kW, installed in the side port is typically used to supply built-in redundancy, but can be used to raise overall heating capacity in high-demand scenarios.

The specialised flanges angle the primary heating elements downward into the vessel ensuring water is heated from the bottom of the tank for optimal efficiency. This energy efficiency is further improved through the addition of 100-125 mm removable insulation.

Alongside the advantages of built-in redundancy, the multiple immersions allow for individual element control. Adveco can supply bespoke control box systems that enable full, individual control of temperature, with easy switching and customisation allowing for varying periods of demand or differential tariff supplies.

Manufactured from high-grade AISI 316L austenitic stainless steel, the Adveco SSB-E range is designed and manufactured to the requirements of the Pressure Equipment Directive (97/23/EC) capable of delivering a maximum working pressure of 6 bar at 85°C. All vessels are tested to the procedure defined in BS EN 12897:2006 and are WRAS certified.

With a wide choice of water capacities, single or double flanges plus a range of immersion sizes and combinations, the Adveco SSB-E provides a bespoke water heater for the most demanding commercial hot water applications.

Discover more about SSB-E and Adveco’s other stainless steel hot water tanks for your bespoke applications.

Fossil Fuels – Their Future In UK Commercial Buildings

The future of fossil fuels is a key issue that needed to be addressed by the government’s Heating & Buildings Strategy report which was published late last year. Statistics (PDF) from the Non-Domestic National Energy Efficiency Data-Framework (ND-NEED) from the Department for Business, Energy, & Industry Strategy (BEIS) defined more than 1,656,000 non-domestic buildings in England and Wales at the end of March 2020. 278,000 or 17% of this building stock is off-gas grid. It is estimated that these non-domestic buildings are responsible for nearly one-fifth of the UK’s carbon emissions, a scenario that will be further exacerbated by a predicted one-third rise in non-domestic floor space by 2050.

A major function of the campaign to Build Back Greener, the report outlines the near and long-term ambitions for phasing out unabated fossil fuels and a transition to low-carbon heat in order to achieve net zero in the UK. The intention is to use ‘natural replacement cycles’ and seek ‘trigger points’ to set long-term expectations within the building sector.

For commercial on-gas-grid buildings, this means putting in place a process to phase out installation of new natural gas boilers from 2035, with a caveat that the costs of investing in low-carbon alternatives have been suitably reduced. To achieve this will require the development of the market for replacement low-carbon sources of heat. The core technology for driving these new markets will be heat pumps, but there is also to be a consideration for other natural gas replacements. By 2026 the government intends consultation to be completed on the case for gas boilers/water heaters to be hydrogen-ready. The process of ‘greening the grid’ is perhaps the most interesting and least disruptive option, improving efficiency and replacing the current supply for those already connected to the gas grid with alternative low-carbon fuels, whether biomethane or hydrogen injection into the gas supply. The government has already committed to enabling the blending of hydrogen in the gas grid (up to 20% volume) and continuing to support the deployment of biomethane through the Green Gas Support Scheme as a method for decarbonising the gas grid.

To support early adopters in the small business space and lure them away from appliances that burn fossil fuels it has been proposed that a new Boiler Upgrade Scheme be launched this year which will support the installation of low-carbon heat pump based heating systems with a payment of £5,000, in line with domestic applications. Given the current additional complexities of commercial systems, with higher temperature demands, this may not be enough to encourage early adoption without the support of higher temperature devices designed specifically to meet commercial DHW demands. To further drive early adoption, the intent is to limit support for the construction of new gas grid connecting heating systems, effective this year. That does not apply to existing legacy structures with a grid-gas connection. Replacement boiler or water heater connections should be, as a minimum, more efficient than those being replaced. This it is proposed will be driven by the application of smart controls and supported by a new Boiler Plus standard that reflects improved efficiency and carbon savings. This should ape conditions set in ERP standards in 2018 for new boilers and emissions set under SAP10. Given that the latest generation of gas-fired condensing boilers and water heaters already greatly exceed the mandated requirements this policy could be seen to be redundant before it ever comes into law.

For the moment if your business uses gas, then you can upgrade to new gas appliances up until 2035, with hydrogen-ready options extending that window well into the 2040s based on current appliance lifespan. If you are considering upgrading a boiler of water heater, you could opt for a natural gas appliance, one that is not considered hydrogen-ready, for at least the next ten years without concerns of breaching new regulations, so long as the new unit is more efficient than the unit being replaced. This provides a safety net while assessing new technology options prior to the 2035 deadline. It would also be well worth considering the implementation of solar thermal preheat for gas-fired systems if you wanted to make sustainability commitments with proven and genuinely renewable technology.

Off-Grid, But Still Being Watched

For the 17% of commercial buildings currently operating off the gas grid, many of which will use LPG variants of boilers or water heaters versus oil, the report proposes phasing out the installation of new fossil fuel heating systems and switching to low-carbon alternatives. Plans would see the introduction of regulations to address large off-gas-grid non-domestic buildings (over 1,000m2) no earlier than 2024, followed by small and medium non-domestic buildings from 2026. Where low-temperature heat pumps cannot be reasonably or practicably accommodated other low-carbon heating options (such as high-temperature heat pumps, and potentially liquid biofuels) may be accepted as an alternative.

The wider aim is to support this near term change with greater investment in heat pump innovation, reducing footprint and making them easier to install. This process is, however, already front and centre for heat pump manufacturers without requesting government support. Better, more efficient, more environmentally and cost-friendly appliances is a clear market driver. At Adveco the recent introduction of the FPi-32 ASHP is a case in point, being extremely compact and better for the environment whilst being more efficient and therefore more cost-effective to operate. Despite being off-grid, potential developments in hydrogen delivery could also be a significant development for the future of fossil fuels, especially in more rural areas, although commercial off-gas grid sites are not uncommon in larger urban areas.

To further encourage this adoption, support for new LPG and oil heating systems could well be refused from this year onwards, with the potential for limited commercial funding support for replacement schemes, depending on scale, coming from the Public Sector Decarbonisation Scheme or the proposed Boiler Upgrade Scheme.

The process of transitioning commercial buildings from fossil fuels to low-carbon will, the report accepts, be gradual. It describes a process similar to the electrification of vehicles, which has depended on a mix of incentives and reducing the cost of entry.

Details of any incentives and clear evidence of where cost reductions are to come from remain hazy. Currently, production and operational costs of heat pumps remain high in comparison to traditional gas appliances that make use of lower-cost fossil fuels. The report, however, anticipates aggressive cost reductions of at least 25-50% by 2025 leading to parity with boilers by 2030. This then anticipates the natural replacement cycles of heating systems throughout the late 2030s and 2040s’ where capital expenditure on low-carbon replacement technology should it believes have lowered substantially. This is why 2035 has been set as the date when all new heating system installations should be low-carbon or hydrogen-ready (at least in those areas where future hydrogen supply has been established) effectively reducing the broad use of fossil fuels across a wide span of the commercial built environment.

FUSION Commercial Hybrid Hot Water Systems from Adveco

  • FUSION is a complete range of low carbon hybrid heat pump and electric hot water systems
  • Resilient stainless steel water heating suitable for all UK regions
  • Compact design for new build and refurbishment projects seeking greater sustainability

Commercial hot water specialist Adveco, introduces the FUSION FPH-S range of low carbon, all-electric, packaged hybrid hot water systems. FUSION harnesses Adveco’s FPi32 Air Source Heat Pumps (ASHP), a high-pressure ATSH calorifier with electric immersion, controls, and metering to provide a reliable, high-temperature, sustainable and cost-effective system for new commercial build and refurbishment projects.

FUSION is available in 16 pre-specified variants with 6 or 10 kW preheat and 9 or 12 kW electric top-up, with capacities ranging from 200 to 500 litres all rated at 10 BAR for high-pressure applications. Able to meet a range of continuous capacity hot water demands from 257-377 litres/hour makes FUSION highly adaptable for a wide range of commercial buildings.

The FPi32 ASHP is specified to supply a working flow of 50°C for system preheat throughout the year, even when ambient air temperatures drop as low as -25°C. Electric immersion top-up then raises system temperatures in the calorifier to the necessary 60°C to meet commercial requirements for safe hot water demands. The stainless steel construction of the ATSH also makes it an excellent all-rounder, resistant to soft water corrosion and, with FUSION’s unique low electric immersion heat intensity (6W/cm²), is more resistant to scale build-up in hard water areas.

The physical design, dedicated controls and integrated metering ensure the ASHP preheat, and immersion work seamlessly to deliver the highest operational efficiencies. This enables FUSION to make the greatest gains possible from the heat pump, even when ambient temperature and system demands fluctuate. These gains offset much of the direct electrical energy usually required, delivering 53% carbon emissions saving and helping control the operational costs of providing business-critical hot water.

“For organisations with small to medium basin and sink led hot water demands and a desire to embrace a more sustainable business model, the FUSION FPH-S range provides a single, easy to accommodate, highly effective response,” says Bill Sinclair, technical director, Adveco. “By choosing one of these packaged hybrid water systems you gain optimum efficiencies, lower your carbon emissions and can be assured building regulations are being met for your commercial project.”

Fusion FPH-S Features

  • 16 pre-sized variants to meet a wide range of applications
  • 200, 300, 400 and 500-litre capacities
  • 6 or 10kW ASHP preheat
  • 9 or 12kW direct electric immersion heating
  • 257-377 litres/hour continuous capacity
  • 10 BAR high-quality AISI 316Ti and 316L stainless steel vessel (PED (97/23/EC), EN 12897)
  • Dedicated control system for simple operation and maintenance checks
  • Lower global warming potential with R32 ASHP
  • Compact space-saving form factor

Calorifiers and Hot Water Storage in Corrosive Water Conditions

For many companies, the assured availability of hot water is a business-critical issue, but one that can quickly become costly for those operating in the southwest and northwest of the UK, the Welsh coast and throughout Scotland. With a low pH, low total dissolved solids (TDS) and negligible buffering capacity, these naturally soft water areas prove highly corrosive to glass-lined vessels used as calorifiers and hot water storage.

Glass is, given the right conditions, generally resistant to attack from most chemicals and corrosive materials and easier to clean, making it a popular choice for lining steel vessels used in hot water systems. But corrosion is a complex phenomenon, and in naturally soft water conditions, despite the use of sacrificial anodes, glass-lined vessels can rapidly succumb to critical corrosive damage.

Pressure to Perform

In addition, the taller the structure, the greater the pressure requirements on the system, particularly since a common design choice is to locate the plant room in the basement. In order to meet, even small demands with a consistent, strong flow of hot water systems inevitably are oversized, adopting a larger, often bespoke tank.

This immediately exacerbates the existing threat, as oversizing, or the failure to correctly balance water flow also contributes to system corrosion. Oversizing of the pumps leads to high-velocity hot water circulating through the system and suspended solids in the water are driven against the metal leading to erosional corrosion. This process helps accelerate the soft water corrosion at points where water changes direction, such as when passing into or through tanks.

Glass-lined water vessels used as calorifiers and hot water storage under these conditions can potentially fail due to corrosion in a matter of just months – even with the use of sacrificial anodes. For these reasons, manufacturers will reduce or have even ceased to offer warranties on glass-lined products installed in these soft water regions. As a result, their specification into projects in these regions really can be a false economy.

Change to Resistant

Far more resistant to these water-side assaults are stainless steel vessels. Although there is a higher upfront cost, this would be easily offset by the relative longevity of the appliance. However, projects with smaller, yet higher pressure hot water demands, will still face the issue of oversizing. This further extends capital costs, of products, installation and the need for greater plant room space. As a result, project costs can become prohibitive for stainless steel, resulting in the specifying of the less expensive glass-lined alternatives gambling that they will prove resistant enough in the mid-long term.

Adveco addresses these concerns with its ATSx range of compact stainless steel, high-pressure hot water tanks. Specifically designed to serve as buffer vessels (ATSB) and indirect hot water calorifiers suitable for use with lower capacity, high-pressure commercial applications in soft water areas. The ATSx range provides specifiers and contractors with a wide choice of calorifiers and hot water storage vessels all rated to 10 bar as standard, which are by far the most efficient and cost-effective choice for businesses with smaller system demands.

Another advantage provided by the indirect water heaters in this range (ATSI, ATST, ATSH & ATSR) is that due to the transferral of heat through the walls of the heat exchanger element the two fluids do not mix. This allows for more options in terms of the external heat supply and introduces a range of renewable technologies that use other fluids for heat transfer including solar thermal collectors and Air Source Heat Pumps. The twin coil ATSR has been specifically designed for these lower-temperature renewable applications. These calorifiers are also relatively simple to install, since there is no burner, there is no need for a gas supply to be directly connected to the appliance and the is no requirement for a flue.

As with any hot water application, understanding the relationship between storage and recovery, and correct sizing is extremely important for efficient and cost-effective operation. Integrating a stainless steel calorifier within a hot water system gives you a number of design options, with a large efficient boiler a calorifier can be smaller avoiding unnecessary capital and ongoing operational expenditure. At 200 to 1000 litres the ATSx range provides a compact, tough resolution for lower demands applications in those soft water areas. If your project has pressure requirements greater than six bar, then the ATSx vessels are by far the most efficient and cost-effective choice for your project.

If the boiler is smaller, or demands for hot water are greater, then going too small means the storage could prove inadequate and the system will not achieve its operational requirements. For projects with larger demands or requiring greater customisation Adveco can support the project with the SSB, SSI and SST ranges of bespoke stainless steel calorifiers and hot water storage vessels.

Discover more about the Adveco ATSx range.

Learn more about soft water corrosivity.


Adveco commercial hot water and heating. Speak to Adveco about tackling global warming through efficient, low-carbon commercial hot water and heating systems (For schools, hospitals and care homes too!)

Call us on 01252 551 540 or see our other contact details.