mould, virus and dust particles IAQ

IAQ in Commercial Buildings

Given that most of us typically spend up to 90% of our time inside buildings, indoor air quality (IAQ) is a serious consideration, especially as it relates to the health and comfort of the people who occupy it. Poor IAQ can have several negative health effects, including respiratory problems, headaches, fatigue, and allergies. It can also lead to decreased productivity and increased absenteeism.

Despite hybrid working becoming firmly entrenched across the country, IAQ remains an especially important issue within commercial buildings, given the significant time people still spend within them, whether working or visiting. IAQ can be affected by a variety of factors, including the building’s ventilation system, the materials used in its construction, and the activities that take place inside it.

The World Health Organisation (WHO) guidance on air quality has advised member states to consider air pollution to be as big a threat to human health and well-being as climate change and adjusted almost all of its previous maximum target levels for airborne pollutants downwards. It linked long-term exposure to even relatively low concentrations of ambient and indoor air pollution to lung cancer, heart disease, and strokes – putting the health impact of pollution on a par with poor diet and smoking.

There are several things that can contribute to poor IAQ in commercial buildings. Some of the most common causes include:

Many building materials, such as carpets, furniture, and paints, can release harmful pollutants into the air. These pollutants can include volatile organic compounds (VOCs), formaldehyde, and asbestos.

Pollutants from activities that take place inside a building can also contribute to poor IAQ. For example, cooking, smoking, and using cleaning products can all release pollutants into the air.

And if a building’s ventilation system is not working properly, it can’t remove pollutants from the air. This can lead to a buildup of pollutants and poor IAQ.

When the Covid-19 pandemic struck, highlighting the role played by poor-quality indoor environments in the spread of viruses and other airborne contaminants, new standards were deemed necessary, elevating publicly available specifications in development by the British Standards Institute and BESA to a full British Standard BS40102-1.

The new standard gives recommendations for measuring, monitoring, and reporting indoor environmental quality (IEQ) in all types of non-domestic buildings. It includes an evaluation and rating system for air quality, lighting, thermal comfort, and acoustics.

Given that building retrofit work carried out to improve energy efficiency had, in many cases, led to poorer quality ventilation this new evaluation will give building managers a benchmark score to help them identify areas of below-par performance. This enables planned improvements which include IEQ measures in any retrofit and renovation work to improve the health and well-being of occupants.

To meet the new standard organisations will need to tackle conditions that have a direct impact on human health including humidity, and excessive levels of CO2, CO, NO2, volatile organic compounds (VOC), airborne particulates and mould.

Adveco has for many years operated a system of checks to ensure the comfort and safety of buildings, including initial system commissioning to ensure correct and safe installation of appliances, in particular its gas-fired water heating and flues. This is especially important in controlling and safely removing any CO2 and NOx emissions from proximity to building users. Regular annual service is a critical facet of such safety checks, yet can be a process that slips once products are no longer under their initial warranty period. This is both a false economy and of potential danger to building users. While new builds will embrace all-electric systems which effectively negate NOx and on-premise CO2  generation, pre-existing commercial sites need to be increasingly vigilant, especially when ageing gas-fired systems remain in use. Mould, a type of fungus which produces airborne spores, is also a contributor to poor IAQ so regular service also helps to identify or prevent cases of damaging corrosion (in soft water areas) and limescale build-up (in harder water areas) which can lead to leaks that then encourage growth of mould in plantroom areas.

Setting IEQ performance benchmarks will make it easier for facilities managers to target problem areas, but British Standards will require further tightening if they are to keep abreast of the WHO’s more stringent guidelines. 

If you operate buildings with ageing gas-fired hot water systems and have concerns about IAQ or wish to reduce carbon emissions as part of a sustainability strategy, speak to Adveco about Live Metering, system assessment and replacement options. Whether looking for high-efficiency, ultra-low emission gas appliances such as AD / ADplus water heaters and MD boilers, or a transition to electric boilers, heat pumps or solar thermal we can help with system assessment, replacement design, supply and ongoing service for more efficient, comfortable and safe working environments.   

zero carbon footprint for the public sector

Public Sector Decarbonisation Latest Funding Phase

The UK Public Sector Decarbonisation Scheme (PSDS) is a government-funded program designed to support the UK’s net zero emissions target by 2050 by providing grants to public sector bodies to help them decarbonise their buildings. This is important as most of the buildings in the public sector still rely on burning fossil fuels for heating, hot water, and catering. 

Phase 1 and Phase 2 of the PSDS have been successful in helping to decarbonise public sector buildings in the UK. The schemes have awarded over £1.75 billion in grants to over 1,300 public sector bodies, which have helped to decarbonise more than 2,000 public buildings. These projects have resulted in a reduction of more than 1.25 million tonnes of carbon emissions.

Who can use the PSDS?

The scheme is open to a wide range of public sector bodies, and it provides significant financial support for decarbonisation projects. If you are a public sector body that is looking to reduce your carbon emissions, the PSDS is a great option to consider.

The PSDS is open to all public sector bodies, including central government departments, local authorities, schools, hospitals, police forces, fire and rescue services and other public buildings.

The PSDS has been a successful program so far. In Phase 1, which ran from 2020 to 2022, the scheme awarded over £1 billion in grants to more than 1,000 public sector bodies. These grants have helped to decarbonise more than 1,500 public buildings, resulting in a reduction of over 1 million tonnes of carbon emissions.

Phase 2 of the PSDS, which ran from 2021 to 2022, awarded £75 million in grants to a further 300 public sector bodies. These grants have helped to decarbonise more than 500 public buildings, resulting in a reduction of a further 250,000 tonnes of carbon emissions.

Why should public sector bodies apply for funding?

There are a number of reasons why public sector bodies should apply for funding from the PSDS. These include:

  • Helps reduce fossil fuel emissions as well as making public buildings more comfortable and cheaper to warm. 
  • To reduce their carbon emissions and help the UK reach net zero.
  • To save money on energy bills.
  • To improve the energy efficiency of their buildings.
  • To create jobs in the low-carbon economy.
  • Gain ongoing client and technical support on project delivery. 

Phase 3c of the PSDS

Phase 3 of the Public Sector Decarbonisation Scheme, worth £1.425bn, was launched on behalf of the Department for Energy Security and Net Zero in 2021 to supply grants to public sector bodies over the period 2022 to 2026. Phase 3c of the PSDS was launched this month.

For Phase 3c of the PSDS, an additional financial year of funding has been granted by the Department. This funding increases the value of the overall funding to the scheme and will enable Phase 3c projects to deliver across two financial years.

Phase 3c of the Public Sector Decarbonisation Scheme has up to £230 million available in 2024/25. The budget available in 2025/26 will be confirmed this autumn though applicants should assume a broadly balanced profile across 2024/25 and 2025/26.

The Application Portal for Public Sector Decarbonisation Scheme Phase 3c is expected to open in the autumn and comes with soft sector caps (divided by Health, Education and Other) to ensure a more balanced distribution of funds across sectors. 

Applicants can submit separate applications for separate projects or combine several projects for delivery across one or two financial years. Applicants can also include energy efficiency measures and other enabling works, that are additional to the replacement of the fossil fuel heating system, where they support a whole-building approach to decarbonisation. 

To apply for Phase 3 funding visit the PSDS website or visit Adveco’s Net Zero resources to understand how funding can be used to support decarbonisation projects that deliver results today. For public sector buildings with gas-fired systems please talk to us about metering your buildings to understand how low-carbon technology can be successfully used to lower carbon emissions without excessively driving up capital funding.  

FUSION sink or basin

Sink or Basin-led Projects Go Low Carbon

Sink or Basin Led Projects Go Low Carbon

FUSION sink or basin

For commercial organisations, there is a new pre-sized response to sink or basin-led hot water projects from Adveco.  The next-generation FUSION range from Adveco is a complete range of packaged electric and packaged renewable electric water heaters.

FUSION is a modern, future-proof system that embraces electric water heating and the option to incorporate air source heat pumps (ASHP) to lower carbon emissions in line with government calls for net zero. As an all-electric system, it uses familiar technology that is relatively simple and quick to install, cost-effective, reduces carbon emissions and removes dangerous NOₓ emissions for improved indoor air quality (IAQ) for enhanced occupant comfort. With an increased heating capacity over first-generation Adveco FUSION systems of up to 34 kW, the next generation of FUSION systems offers greater versatility for meeting domestic hot water (DHW) demands across a range of properties used for commercial operations. Projects with small to medium sink or and basin-led hot water demands, taller buildings with basement plant rooms and businesses that depend on 24/7 hot water provision for continuity of service all gain advantages from using FUSION.

The packaged format enables flexibility to specify from a range of cylinders, primary electrical heating, air source heat pumps for pre-heat, and immersions for back-up all supported by Adveco’s bespoke controls to ensure optimal, efficient operation. FUSION cylinders (ATSI & ATST) come with dedicated mounting points for the ARDENT electric boiler, simplifying and reducing the chance of installation errors.

By mounting the electric boiler directly to the cylinder FUSION is a more compact, space-saving option when specifying or having to refurbish an existing plant room. The cylinder connections and clean-out plate are all arranged on the front of the tank for easy access when connecting pre-built pipework with a choice of left- or right-hand side connection, and for regular maintenance. This arrangement also enables FUSION to be situated tightly into a corner, again maximising available space. Corrosion-resistant stainless steel construction makes FUSION’s cylinders perfect for either soft or hard water areas. With 10 Bar operating pressure, the ATSI and ATST are more than capable of serving the needs of taller buildings, especially those with existing basement plant rooms.

The use of the 9, 12 or 24 kW ARDENT electric boiler replaces the use of a single immersion for primary heating. Capital costs are not only equivalent, but ARDENT, with multiple immersions inside its sealed storage tank provides automatically balanced usage to prolong system life and immediate resilience for the boiler should there be a failure of one of its immersions. The typical cause of immersion failure in sink or basin-led systems is the creation of limescale in hard water areas, production of which is accelerated by the higher heat intensity of electrical water heating. This is avoided in FUSION, as the ARDENT is used in a sealed ‘primary’ loop to an indirect coil in the system’s cylinder.  The ARDENT 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, effectively eliminating damage to the immersions by limescale.

FUSION cylinders offer single (ATSI) and twin-coil (ATST) variants with capacities ranging from 200 to 500 litres. Single coil cylinders (ASTI) are used for standard electric indirect water heating with an ARDENT electric boiler (FUSION-E), and the option of an immersion for resistive heating ‘directly’ to water in the cylinder (FUSION-Eplus).

Dual-coil cylinders (ATST) enable the addition of a 6 or 10 kW FPi32 monobloc air to water heat pump. The ASHP is connected to the lower coil and supplies indirect pre-heat to the vessel, while ARDENT is connected to the upper coil to provide primary indirect heating (FUSION-T & -Tplus). FUSION E systems come with a thermostat and overheat thermostat as standard, but for renewable variants featuring dual-coil ATST cylinders and ASHP, optimisation within the FUSION system comes from Adveco’s purpose-built FUSION Control Box. This smartly balances the two heat sources enabling the water in the cylinder to be heated in the most efficient way. The heat pump’s contribution is maximised, achieving a working pre-heat flow temperature of 50°C under UK weather conditions, even if the ambient air temperature drops as low as -25°C.

With the cylinder water pre-heated by the ASHP, the ARDENT boiler is not required to work as hard to raise flow temperatures to the 65°C demanded by commercial applications. Electrical demand on the boiler is reduced by as much as 30%, delivering operational savings and reducing carbon emissions by up to 71%. This variant is perfect for organisations seeking to invest in a water heating application as part of a decarbonisation strategy without losing sight of higher operational costs associated with all-electric systems compared to equivalent gas-fired water heating.

Where hot water demands become a business-critical service, FUSION will also support the addition of an Adveco backup immersion providing additional resilience. Fitted into the front-facing clean-out access, the immersion ensures there is no single point of failure for assured service provision. When only used as an emergency heating source, or during periods of unplanned excess demand, the inclusion of an electric immersion can be extremely advantageous. For FUSION systems incorporating the additional backup immersion (FUSION FPH-Eplus & FPH-Tplus) controls are further extended to incorporate SMS output to advise building managers of a fault scenario and automated engagement of the immersion back-up to guarantee business-critical hot water supply.

For commercial organisations specifying a sink or basin-led hot water system for new buildings faced with regulatory changes on new gas connections, or planning to move from existing gas-fired systems to electrical alternatives FUSION provides an impressive range of choices whether cost, sustainability or business security are the driving factors for specification.

Read more about Adveco FUSION


All electric banner

All Electric ? Sustainability & Water Heating Pt.3

In this three-part series, Adveco has so far addressed the role of air source heat pumps and solar thermal as a source of low carbon preheat, in this final part, we consider the future of gas and the adaptation to all electric applications for implementing more sustainable hot water in commercial buildings.  

Read Part 1 Sustainability & Hot Water – Which Path Is Right For Commercial Properties? 

Read part 2 sustainability & Hot Water – Using The Sun

Despite the pressure to address carbon emissions in building stock in the UK, the fact is we are still waiting for clear advice at a government policy level. The final decision on energy solutions remains unresolved. So do you opt to go all electric with equipment now on the basis that the grid will become zero carbon or hold out for the option of carbon-free gas such as Hydrogen, which in terms of infrastructure change and refurbishment would be potentially quicker, cheaper and less disruptive.

As indicated, if your building has a gas connection and has high hot water demands it remains the most cost-effective option. Additionally, new gas-fired appliances operate with ever-reduced emissions, and most are ready to accept the initial proposed 20% hydrogen blends in the gas grid as early as 2024 without requiring any alteration. ‘Hydrogen Ready’ units are, with a replacement of the burner and pre-mixer, even capable of burning 100% hydrogen, but that scenario is some time away. Should hydrogen be accepted by the government as a function of net zero we would not expect 100% feeds to be in place nationally until 2040 with the grid changeover beginning in the early to mid-2030s. Retaining an existing gas connection, therefore, provides a degree of futureproofing should green gas technology be embraced.

What is clear though is that the latest building regulations (Part L, 2021) have radically revised the carbon intensity of electricity from 519g CO/kWh ten years ago to just 136 today. Gas in the same period has fallen from 240 to 233. Whilst the regulations do not yet exclude gas, they do advantage the adoption of all electric systems. We have demonstrated that renewables have a critical role in reducing the carbon emissions of a system, as well as offsetting the costs of heating water with direct electricity.

Gas-based hot water applications are, by a factor of 3.8, currently cheaper to operate than direct grid-electric systems. Using heat pumps can offset 25-35% of those energy costs, but this still leaves a considerable excess operating charge because of the need to provide top-up energy for safe operating temperatures. Historically, additional system top-up was provided by electric immersions, which for backup purposes and occasional peaks in demand whilst more expensive was acceptable. The shift to fully electric systems has put a greater onus on the technology which was never designed to provide primary heat. The costs are excessive and as we indicated, should they be deployed hard water, can rapidly develop scale leading to permanent damage in a remarkably short time. For this reason, we recommend the replacement of immersion technology with smaller electric boilers that are both more efficient, and, because they operate in a closed loop will avoid the issues of systems scaling up.

Perhaps the most detrimental issue we see today as a result of replacing gas with electricity is the propensity to oversize the new all electric system, replacing gas appliances with electric alternatives with like-for-like capabilities. Hot water systems have been inherently oversized in the past through a lack of understanding of application design or concerns over providing suitable backup to ensure system continuity. The result of oversizing is however always the same, unnecessary capital costs for system supply and installation, but when replacing gas with electricity, oversizing leads to greater electrical demand and should that exceed a building’s available amperage of electrical supply, project installation costs will inevitably soar, or even stall the project.

This can best be avoided by understanding your building’s actual hot water demands and designing the replacement to meet those specific needs. There is an art to designing hot water systems, but real, actionable data is priceless. When considering options for introducing sustainability the best advice we can give is to understand your needs first. Live metering is an easy, non-intrusive way of securing the valuable operational data you need to make informed decisions that deliver on expectations to lower carbon emissions without incurring unforeseen costs.


Care Home Sustainability

Care Home Sustainability

Care home sustainability is growing on the radar of operations & building managers. It is becoming a facet of the decision-making for families and an indicator of the personal comfort the residential client can expect from a facility.  Refurbishing existing facilities has a number of implications, not least cost, but also disturbance of residents, so where can quick, easier wins be made as part of a decarbonisation strategy?

Every care home needs hot water. From basins to baths and showers, catering and wash down. Most facilities will run successfully on a system based around gas-fired water heaters unless a new build in which case the preference is to move to electric water heating to take advantage of the increasingly less ‘dirty’ grid. This does have implications for running costs, with electricity on average costing as much as 3.8 times that of gas. So why change things? The simple answer is net zero, and the need to be more sustainable. Because of the ubiquitous need for hot water, which can account for as much as 30% of a building’s daily energy demands, addressing how it is secured is one of the best ways of making active carbon savings today to begin delivering care home sustainability.

Deploying either heat pumps or solar thermal as a renewable to provision the initial preheat, is the most logical approach. Where problems and unnecessary costs can quickly arise is when existing gas-fired ‘top up’ water heating is replaced with like-for-like electric which can lead to gross system oversizing. Domestic hot water (DHW) systems that deliver care home sustainability should still be designed to accurately meet a business’ needs. At Adveco, our application design team has a thorough knowledge of residential care, understanding the peak hour and length of the peak, which are the starting point for determining demand and ensuring the hot water system is correctly sized.

This demands a bespoke approach as every facility is different. The number of rooms, facilities such as basins, showers, deeper baths and guest mobility, all impact on the sizing. The physical constraints of the property, from plant room and roof space to noise levels all impact technology choices.  Adveco can advise on this sizing and provide accurate monitoring to ensure applications are fit for purpose and future proof. As a result, decisions to move to more sustainable operations are optimised and do not leave properties facing unwarranted capital or unexpected new operational costs.

Visit Adveco’s healthcare resource page

Healthcare Sustainability

Healthcare Sustainability

Recent research by the University of Exeter sets out the scale of the challenge the NHS faces if it is to achieve healthcare sustainability targets set under the government’s net zero plan by 2040, a full decade ahead of the wider commercial sector.

With a calculated carbon footprint equivalent to 31 million tonnes of CO2, 62% of which can be attributed to its wider supply chain, the NHS must reduce emissions by 8% each year through until 2036.

This means stakeholders across government, NHS and industry need to be working together in order to provide new standards for procurement and innovation to ensure sustainable practices.  One area that accounts for a consistent and definitive need within the NHS is the provision of hot water. A core facet of hygienic working practices and the provision of healthy spaces for treatment and care, heating water can be an energy-intensive process, accounting for as much as 30% of daily energy demands. It is also a provision that can immediately deliver a reduction in carbon emissions and operational costs once implemented, whether a building is new construction, or more likely a refurbishment of existing property within the NHS estates,

For more sustainable domestic hot water (DHW) systems, we expect healthcare facilities will look for hot water to be generated at a commercial scale via multiple localised systems that each provide hot water to wash hand basins and showers for a dedicated area. This has been the most common use case seen across recent pandemic-driven refurbishments for example. This typically will see systems arranged on a ward-by-ward basis, but appliances may also supply hot water to local shared spaces where appropriate. Such systems will demand hot water be stored and distributed at a minimum temperature of 60°C. Working flows could be required up to 75°C with minimum return temperatures not below 50°C.

The overriding issue is that NHS health technical memoranda (HTM) 04-01* states that, preheat vessels cannot be used unless they can be guaranteed to preheat to a minimum of 45°C. This could immediately preclude for instance the use of solar thermal as a lone source for preheat. However, it matches well to the minimum working flow temperature for preheat that we would design into a system utilising the current generation of air source heat pump. Solar thermal would be more effective for the provision of top-up heating. Awareness of this facet of the HTM has historically been either ignored or missed, so solar thermal has been deployed in a number of health facilities, often successfully, and Adveco has been servicing hospital solar systems for more than a decade in such locations as Merseyside and Greater Manchester. That said, we are aware of systems that have not met the requirements of the HTM leading to costly decommissioning.

To achieve net zero and meet NHS mandates for DHW a typical sustainable application would see hot water generated via a pair of parallel-arranged hot water cylinders to ensure redundancy. These would be sized to provide 60% of the hot water demand for the area served based on a peak 15-minute duration loading. The heat into the cylinder would come from a combination of solar thermal collectors and an air source heat pump working in conjunction to guarantee the preheat temperature

The design of the system allows for the heat pump to contribute to the incoming cold water.  That ensures 45°C while taking full advantage of the COP of the heat pump.  The solar thermal is employed after the heat pump to heat the water from 45°to 50 or 60°C depending on the time of year. We calculate the solar contribution over the year, with a system able to provide about 10% of the peak output when conditions are at their worst – short days with low sun and heavy cloud cover – rising to 30% under optimal conditions.

Should temperatures of up to 75°C be required, a high-temperature electric heat source would be used. Whilst typically an immersion, we would suggest specifying an electric boiler to avoid issues of scale in hard water areas, also well as delivering further system redundancy since the boiler will incorporate multiple immersions within its chassis. The electric boiler tops up what the solar could not manage. Still, by delivering preheat through both the ASHP and solar thermal system, demands on more costly electric heating are considerably reduced, if not avoided entirely. While higher temperatures will reduce solar efficiency, it is still useful to offset the high-grade heat than the low-grade/high COP heat pump heat and help to deliver on healthcare sustainability targets.

Example three-cylinder arrangement to meet healthcare sustainability and NHS HTM.  The heat pump and solar use a dual coil cylinder with the heat pump on the bottom and the solar on top. With this arrangement, there is no thermal conflict between the heat pump and solar adds what it can. 

The entire tank is heated to 45C by the heat pump and then receives solar top-up. A purge pump would run once per day to use the after heater to heat up the preheater for sterilisation to prevent legionella.

*Reference link

Adveco Appoints Vince Ng To Spearhead CPDs & Support National Accounts

Hot water specialist Adveco announces the appointment of Vince Ng as business development manager driving national sales accounts and Adveco’s continuing professional development (CPD) programme.

Vince will support Adveco’s portfolio of national accounts, including key brands across retail, hotels, restaurant chains and the public sector. Driven by government mandate and the increasing desire to decarbonise operations as part of a wider corporate policy that embraces the advantages of net zero for staff and customers, organisations can use the specialist knowledge Adveco can provide to address energy demands for business-critical hot water supply.

“Whether building brand new facilities or refurbishing existing buildings, Adveco’s application design services, specialist product portfolio and service contracts can help national organisations to control capital and operational expenses,” said Vince Ng, business development manager. “Critically by working in partnership with us customers operating UK-wide can reduce global warming carbon and harmful NOₓ emissions from their hot water (DHW) systems.”

A guaranteed supply of DHW is typically a more complex provision for commercial projects, often requiring bespoke applications that leverage a hybrid technological approach to achieve the necessary quantities and temperatures demanded. To help understand this, Adveco offers a range of CPDs and hands-on training for consultants, specifiers, engineers, installers and energy managers.

Adveco’s existing CPDs already cover sizing domestic hot water systems and maximising contributions from solar thermal. These are now joined by a new CPD, Best Practices for Electric-Based Commercial Hot Water Systems.

As organisations look to alternatives for securing low-carbon hot water this CPD session considers the options of achieving net zero in buildings by cutting carbon emissions through the electrification of water heating. It covers the specification of electric water heating, direct electric and low carbon methods including solar thermal and, in particular, air source heat pumps. This will provide an understanding of the challenges and issues surrounding commercial electric water heating and the importance of pairing kW to litres when designing a system and provide a clear overview of the next stage in the technological development of heat pumps.

“As a provider of hot water technologies, Adveco is proud to have a commitment towards the continued growth of knowledge and experience of professionals in the energy and sustainability sector. All our CPDs, including Best Practices for Electric-based Commercial Hot Water Systems, can be booked now with the training team as face-to-face or remote sessions,” said Vince.

Adveco is accredited with CIBSE for the provision of CPD seminars designed to contribute towards an individual’s professional development.

Book a CPD Seminar now

Gas & Sustainable Buildings

The UK commercial sector is still very much in the early process of adapting to more sustainable working, with many still reliant on fossil fuels. Despite the calls to change to more renewable forms of energy many are continuing to refit with familiar gas technology, so what is the current state of play between gas and sustainable buildings?

Decarbonising UK commercial properties is an immense challenge. They are directly responsible for nearly one-fifth of the UK’s carbon emissions and, since domestic hot water (DHW) can account for as much as a third of a business’s routine energy demands, addressing emissions from hot water generation should be on an organisation sustainability agenda.

In response there are two broad UK-wide strategies: either installation of heat pumps to drive electrification, or, for properties on the existing gas network, switch over to hydrogen as a low-carbon alternative to natural gas.

In 2020 according to the Department for Business, Energy, & Industry Strategy (BEIS) more than 1,656,000 non-domestic buildings in England and Wales, the large majority of which were connected to the gas grid, were consuming more than 172 TWh of gas. The number of commercial properties is set to continue to grow, and though these new builds are opting for electric-only applications, existing buildings face a number of issues, not least the capital expenditure required to modernise services and the increased operational costs from implementation.

For this reason, unlocking the potential of hydrogen represents a familiar, easier and more cost-effective way to transition to more sustainable heating practices in buildings. The International Renewable Energy Agency (IRENA), recently estimated Hydrogen will cover up to 12% of global energy demand by 2050 from virtually nothing today. At least two-thirds of total production will be green hydrogen (produced with renewable electricity) with the remainder covered by blue hydrogen production (derived from natural gas) so long as the carbon capture and storage (CCS) is proved viable.

In the UK, the status of hydrogen remains to be confirmed as part of the government’s push towards attaining net zero by 2050. The Heating and Buildings Strategy published in late 2021 does, however, give an indication of the growing support for hydrogen-based technologies, as does continued government investment in its feasibility. Hydrogen, as a result, is increasingly seen as a core shift in the energy trade and critically, in the wake of demands to reduce dependency on Russian oil and gas, the future for regionalisation of energy supply.

Currently, when comparing average non-domestic gas to electricity tariffs, electricity will cost as much as four and a half times that of gas, making gas the more cost-effective option. Yet it fails to deliver a clear investment in sustainability unless hydrogen is used to decarbonise. That also comes with a number of advantages given the equipment remains familiar to operate and manage. It should ensure capital costs remain lower, while decarbonisation can be accelerated within a property.

For those wishing to adopt the hydrogen approach, there remains a question mark over how quickly, where and in what proportion hydrogen will be introduced into the gas grid. With the ultimate aim of introducing 100% green hydrogen via the existing gas network, gas water heaters and boilers will need to be factory configured to burn hydrogen only. Or be hydrogen-ready, whereby natural gas-compliant appliances can be converted to operate on hydrogen only in the future. These appliances, with the exception of some regional test deployments of hydrogen, are not expected to be actively used with 100% hydrogen until well into the 2030s at the earliest, with a potential national roll-out predicted for the 2040s.

As an interim, the UK is assessing the potential for introducing hydrogen into the existing gas network as a blend at 20% volume to deliver a safer, greener gas alternative that reduces carbon emissions. A blended gas grid has the potential to become a reality by the late 2020s, enabling organisations to become used to working with hydrogen as an energy source with less disruption and no noticeable change in how gas is used within the property.

Can gas & sustainable buildings still co-exist?

For commercial organisations which have recently invested in, or plan to refurbish, existing non-hydrogen-ready gas appliances, the most recent condensing gas-fired models currently on the market should already be able to burn natural gas with a blend of up to 20% hydrogen without requiring any modification.

For example, Adveco’s current ranges of high efficiency, ultra-low emission gas-fired condensing water heater, the instantaneous ADplus and semi-instantaneous AD, as well as the MD boiler range, are all hydrogen 20% blend ready. Such appliances give customers peace of mind when investing in gas-fired water heating applications. With the latest generation of gas water heaters and boilers offering more rugged construction and technology that better manages operation the working life of the appliance is further extended, meaning if purchased today they should continue to operate well into the 2030s. As hydrogen blending becomes commonplace, this then delivers on the desire to decarbonise operations in the easiest and most cost-effective manner as a business user. When these require replacement a wider choice of more advanced, proven and lower-cost hydrogen-ready and 100% hydrogen appliances for commercial applications will be available on the market as the gas network matures and greens.

Gas-fired commercial water heating, therefore, remains a proven and future-proof choice for the working lifespan of current-generation appliances. Not only practical and lower cost to operate, these also deliver a way to introduce a degree of sustainability in the interim before hydrogen can make a real impact so gas and sustainable buildings will develop hand in hand.

With modern building regulations, it is likely that a commercial hot water system, whether it uses gas or electricity, will still also require a low-carbon preheat source to reduce carbon emissions. For properties with an existing gas connection employing solar thermal can be extremely effective in reducing reliance on the existing gas boiler, cutting as much as 30% of the annual energy demands for water heating.

Fortunately, solar thermal also lends itself to working in conjunction with not only conventional or blended gas heating but also other renewable technologies including air source heat pumps. This enables a variety of bespoke, hybrid applications to be considered to meet the varied demands of existing commercial buildings.

Despite the reliance on fossil fuel, the latest generation of gas water heaters and boilers provide a realistic and lower cost option for organisations already connected to the gas grid to leverage technology that offers higher efficiency operation for lower energy consumption and critically ultra-low carbon and NOₓ emissions. Through integration with renewables, they offer a way to further reduce a building’s energy demands and emissions today, as well as the potential to act as a gateway technology to future greener hydrogen blend energy sources at no further cost.  For the next decade or so, they still have an important role to play meaning gas & sustainable buildings will remain a reality, especially if gas supplies can successfully transform from its fossil fuel origins to green hydrogen.

Solar thermal for commercial building projects requiring DHW

Solar Thermal For Hot Water Generation In Commercial Properties

Adveco takes a look at the advantages of deploying solar thermal for hot water generation in commercial properties.  As part of an organisation’s wider sustainability plans, solar thermal offers a proven renewable technology that reduces emissions whilst able to integrate with other sustainable technology including air source heat pumps, direct electric and ultimately, through retained gas connections, hydrogen.

Commercial properties have traditionally sourced domestic hot water (DHW) from systems that have relied on gas boilers or water heaters because of the necessary high temperatures required for safe operation and the cost-effective operation it offers businesses. More recently there has been a trend toward all-electric systems in commercial new builds, driven by calls to support the government’s net zero strategy and cessation of new gas grid connections.

In 2020, according to the Department for Business, Energy, & Industry Strategy (BEIS), there were more than 1,656,000 non-domestic buildings in England and Wales. These properties are directly responsible for nearly one-fifth of the UK’s carbon emissions and, since DHW can account for as much as 30% of a business’s routine energy demands, addressing emissions from hot water generation becomes a key issue.

Whether a commercial hot water system uses gas or electricity, it will require a preheat source to reduce carbon emissions. Today there are realistically two main choices, either heat pumps or solar thermal. Neither technology offers a standalone response for the hot water system that will also require an alternate top-up heat source to meet minimum safe working flows of 60°C, peak demands and periods of low ambient temperatures or poor solar availability during winter months.

As a rule of thumb, new builds will invariably default to heat pumps, whereas properties with an existing gas connection will see greater advantages from the installation of solar thermal for hot water generation.

Currently, when comparing average non-domestic gas to electricity tariffs, electricity will cost as much as four and a half times that of gas. Even if a heat pump can demonstrate a 3 to 1 coefficient of performance (COP), and that needs to be for water with working flow temperatures of at least 45°C, that is not going to be enough to offset the difference in the cost of the gas-alone-fired alternative. Consider also that if direct electric is being used to top up the heat pump system and you are looking at an even wider divergence in operational costs.

Ideally allowing for approximately 20% solar fraction, or the percentage of the total thermal load satisfied by solar energy, employing solar thermal for hot water generation can be extremely effective in reducing reliance on the gas boiler.

Sizing Solar Thermal

Accurately assessing the demands and limitations of a building is critical for the correct sizing of the solar thermal system as the real world always seems to add unforeseen complexity. For instance, up to 25% of the total flat roof space available for solar panels will be limited by the allowance for access and prevention of shade which would otherwise compromise system efficiency. As building footprints become more compact and high-rise, especially in the case of city centres, available roof space to demand sharply decreases and solar thermal will come into competition with other heating and ventilation systems using the roof as real estate for installation. This is where solar thermal is more advantageous than solar photovoltaics (PV). Both approaches are directly comparable when used to offset direct electric water heating, with similar installation costs and annual savings. But in order to match three solar thermal panels taking up 6.6m² of roof space, a 4kW solar PV system will require 25m² to accommodate up to 16 panels in its system.

In general terms, each room in a hotel, care facility or education accommodation within an application design will require a 0.5 m² aperture, which is the area over which the solar radiation enters the collector. For flat plate collectors, the gross area and the aperture will be the same, with Adveco collectors, for example, each measuring 2.24 m². When sized and installed correctly, each solar thermal collector can contribute up to 1400kWh per annum, providing electricity savings of £300 electric and more importantly reducing emissions of CO² by 322kg. A commercial system sized to support an occupancy of 50 will typically require 12-24 panels, whilst smaller systems servicing up to 12 occupants will employ three to four panels. Collectively the panels deliver significant savings on the running costs that are not gained by using heat pumps.

There are also additional advantages that come with using solar thermal compared to heat pumps. Solar thermal operates silently meaning no sound pollution; there are no high global warming potential (GWP) refrigerants; and no specialist registration, such as F-gas, is needed for installation, although installers should be solar trained. A correctly installed and maintained solar thermal system will outlast a heat pump, and maintenance is low, especially if systems are deployed with a drainback capability.


Using solar thermal for hot water generation works but capturing solar energy in a fluid that transfers heat indirectly to the DHW system. The solar fluid must be correctly managed, if left in the panel it can overheat, stagnating into a tar-like consistency which can leave collectors irreparable. Drainback is particularly important for preventing such overheating and resultant damage. It works by draining the fluid out of the system when not in use. This functionality is incorporated into all panels in Adveco solar system designs. Should the power be cut, the system naturally drains the fluid back to the reservoir, without the need for working components, providing guaranteed, low maintenance overheat protection. With such a system in place, solar fluid will last at least eight years before requiring a refresh. Drainback does require a 3m drop from the collector to the plant room to successfully operate, so the location of the plant room and the presence of flat or sloped roofs all come into play when calculating the most effective installation.

Hybrid Future

Fortunately, solar thermal also lends itself to working in conjunction with not only conventional gas heating but also other renewable technologies including air source heat pumps. This enables a variety of bespoke, hybrid applications to be considered to meet the varied demands of commercial buildings.  As solar thermal is (at times) a high-temperature renewable source, the heat pump should be used to supply the initial water heating from cold to 45°C. Solar thermal is then used after the heat pump to top up water temperature from 45°C. Any additional required energy would then be supplied by an immersion heater. This allows the solar to offset the immersion consumption, instead of offsetting the heat pump which already benefits from the COP. Although the solar will lose some efficiency operating at higher temperatures it is better because the COP is higher than the loss of efficiency.

Adveco AD Wall-Mounted Water Heaters For Commercial Properties

  • A range of three compact commercial semi-instantaneous gas condensing water heaters
  • Perfect for applications requiring direct contact with soft and softened water
  • Compact and smart for no-nonsense installation and maintenance

Commercial hot water specialist Adveco, announces the Adveco AD range of high-efficiency condensing gas-fired wall-mounted water heaters. Designed to provide a compact, high capacity and reliable method for delivering instantaneous hot water to a building, the new range consists of three models, the AD16 (27kW rated heat output), AD22 (33 kW) and AD37 (61 kW).

The AD is a range of ‘A’ class energy-efficient wall-mounted water heaters, with a net efficiency of up to 107% for the production of domestic hot water (DHW). With an efficient pre-mix burner and minimal NOₓ and CO emissions, the AD range is an eco-friendly way to serve a DHW system. Featuring a high 1:8 modulation ratio, wall-mounted ADs ensure maximum efficiency even during periods of low demand.

The wall-mounted water heater features a single high-quality patented heat exchanger constructed from a continuous, non-welded run of  AISI 316Ti titanium-stabi­lised stainless steel, providing exceptional construction strength and corrosion resistance. The brand-exclusive three-pass design features large bore, circular tube cross-sections that reduce the collection of debris.

Bill Sinclair, technical director, Adveco said, “For property renovation where space is at a premium or when existing gas appliances need modernising, the AD wall-mounted water heaters range delivers highly efficient operation in a compact form factor. The titanium-stabilised stainless-steel construction of the AD’s heat exchangers is also the perfect response to counter the concerns of corrosion in soft or softened water applications.”

Also included is an inbuilt controller with an LCD display that ensures full temperature control and a maintenance self-check of primary components and functions.

Additional Information

  • Compact wall-hung arrangement
  • High-efficiency pre-mix burner provides a large modulation range
  • Ultra-low NOₓ emissions at 16-29 mg/kWh
  • Available using natural gas or LPG
  • Supports standard concentric or parallel flue systems using an adaptor for low-cost 80/125 mm diameter PP available on request
  • Integrated run/fault signal for connection to BMS