Tag Archive for: Boiler

Part L – New Building Regulations For Commercial Hot Water

Introducing changes to Part L of the Building Regulations (Conservation of fuel and power) for England represents a commitment to raising the energy performance of buildings to provide a pathway to highly efficient non-domestic buildings which are zero carbon ready, better for the environment and fit for the future. Although due to be formally released in 2025, the first of a number of interim measures come into force this month.

Whilst the new regulations will have a profound impact on new-build projects, refurbishment works are likely to be initially affected by the introduction on June 15th of new restrictions on the specifying of poor-efficiency direct-gas fired water heaters. Under Part L, new regulations for hot water systems essentially end like-for-like replacement for non-condensing water heaters by imposing new minimum efficiencies (91% for natural gas and 92% for LPG).

Each new fixed building service, whether in a new or existing building, must meet the legislated values set out for efficiency. Replacement fixed services must be at least as efficient, either using the same or a different fuel as the service being replaced with matching or preferably better seasonal efficiency.

If moving over to a new fuel system, such as oil or LPG to natural gas, it should not produce more CO₂ emissions nor more primary energy per kWh of heat than the appliance being replaced. If ageing renewables such as wind or solar are being replaced the electrical output must be at least that of the original installation, except where it can be demonstrated that a smaller system would be more appropriate or effective. And if work extends or provides new fixed building services energy meters will need to be installed.

When specifying a DHW system, sizing should be based on the anticipated demand of the building (based on BS EN 12831-3). The regulations demand systems not be “significantly oversized,” but we would argue any oversizing will have a negative impact on the efficiency and operational costs of a DHW system. So accurate sizing is critical in terms of delivering an optimal thermal efficiency assessment. That assessment will include the heat generator and any integral storage vessel, but will exclude all secondary pipework, fans, pumps, diverter valves, solenoids, actuator and supplementary storage vessels from the calculations.

As a guide the minimum thermal efficiencies for natural gas-based DHW systems, based on gross seasonal efficiency of the heat generator are:

91% –                                 Direct fired for new building with >30kW output*

91% –                                 Direct fired for new building with <30kW output*

91% –                                 Boiler efficiency for indirect-fired systems in new & existing buildings

100% assumed                Electrically heated new & existing buildings

* Product standard BS EN 15502-2-1:2012 for gas-fired boilers and appliances of a nominal heat input not exceeding 1000 kW / BS EN 89 gas-fired storage water heaters for the production of DHW

Adveco carries of range of stainless steel direct-fired condensing water heaters, the AD and new ADplus ranges, and MD boiler range, which all leverage advanced burner control to drive efficiency as high as 106%. Plus glass-lined condensing water heaters such as the AO Smith BFC Cyclone (97% efficient) and Innovo (98% efficient) provide a range of choices that already exceed the latest regulations under Part L and provides a safety net should regulations tighten in the future.

As with the broader regulations relating to space heating, controls form a necessary element of the new Part L regulations for combustion heated DHW systems. These all must incorporate a time control (independent of space heating circuits) and an electronic temperature control.

Additionally, regulations call for fully pumped circulation where compatible with the heat generator for primary hot water circuits. Automatic thermostatic control to shut off the burner/primary heat supply when the desired water temperature is reached, and primary flow if the system temperature is too high for all direct-fired circulator systems, direct-fired storage systems and indirect-fired systems. Direct-fired continuous flow systems should include a heat exchanger flow sensor to control outlet temperatures and detect insufficient flow with burner/heat input shut off. A high limit thermostat is also required to shut off the primary flow if the system temperature is too high.

Point-of-use, local and centralised domestic hot water systems should have automatic thermostatic control to interrupt the electrical supply when the setpoint storage temperature is reached or the system temperature gets too high. If there is an over-temperature trip manual reset should be possible.

Local and centralised DHW systems should have both a 7-day time control and the facility to boost the temperature by using an immersion heater in the cylinder.

Instantaneous water heaters should include a flow sensor to control the rate of flow through the heat exchanger. If the sensor detects insufficient flow, it should shut off the electrical input. Plus, a high limit thermostat is required to shut off the primary flow if the system temperature is too high.

Alongside gas, solar thermal is likely to be applied in the notional building unless heat pumps meet 100% of the actual building’s demand. Solar has been used in calculations in the past to overcome the poor fabric performance of a building. But, given the broad majority of heat pumps are currently used for preheat on commercial DHW applications, at most offsetting 70% of the energy demanded, solar thermal has a valid role to play and it’s a proven sustainable technology. Our expectations are for commercial DHW systems to continue in a familiar manner for the near to mid-term, with gas appliances used to provide cost-effective supply, especially during grid peak hours. Heat pumps and/or solar thermal will be deployed to provide preheat to that system.  As efficiencies improve and higher water temperature (more than 60°C) are achieved through heat pumps we see gas appliances slowly being phased out unless they can be replaced with green gas (hydrogen) alternatives. This naturally leads to the provisioning of hybrid systems for the coming decade, optimising a mix of current technologies that address the latest regulations, reduce emissions and crucially deliver value for money with lower operational costs.

These measures are designed to enforce a move away from fossil fuels to low carbon technology for heating and domestic hot water (DHW) and set a more rapid timeline. There is no doubt these new measures will ultimately represent a seismic shift in thinking when it comes to commercial hot water and heating applications, but a cushion has been built in to allow for the development of systems that are necessarily more complex than would be seen in domestic settings. This brings considerable opportunities for developers and specifiers willing to consider both existing and new technologies in order to deliver compliant applications in the next five years.

Whilst a fabric first approach is encouraged, low carbon technologies are being emphasised. This ultimately means heat pumps for the broad majority of DHW applications where there is a low heat demand. For commercial properties where there is typically a high heat demand gas is still allowed while the industry works to develop suitable alternatives.

One final observation on the implication for the specification and installation of commercial DHW relates to completion requirements. Part L tightens the commissioning requirements to reduce the gaps in performance over design and is intended to deliver improved project handover with accurate energy usage predictions. As a result, we can expect to see revisions of commissioning processes across the industry to help streamline delivery and speed up handover, crucial if government roll-out targets for low carbon technologies to achieve Net Zero by 2050 are to be met and superseded by commercial organisations.

 

Regulation changes take effect on 15 June 2022 for use in England. It does not apply to work subject to a building notice, full plans application or initial notice submitted before that date, provided the work for each building is started before 15 June 2023. Regulation changes do not currently apply to Wales, Scotland or Northern Ireland. 

 

 

 

 

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.

Unlocking The Potential of Hydrogen

For many, unlocking the potential of hydrogen represents a familiar, easier and more cost-effective way to transition to more sustainable heating practices in buildings. It is also 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.

In the recent report, Geopolitics of the Energy Transformation, from the International Renewable Energy Agency (IRENA), hydrogen it is estimated will cover up to 12% of global energy use by 2050, with at least two-thirds of total production being green hydrogen (produced with renewable electricity) with the remainder blue hydrogen (derived from natural gas).

Here 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 begin to give an indication of the growing support for the technologies currently being tested.

The government’s commitment so far extends to the testing and evaluation of the potential of hydrogen as an option for heating workplaces. In partnership with industry, the intent is to “clearly define the evidence needed to make a policy decision about the role hydrogen for heating can play in our future energy system.”

To this end, The Department for Business, Energy and Industrial Strategy (BEIS), supported by Innovate UK and Innovate UK KTN, have launched the Net Zero Hydrogen Fund (NZHF) which was most recently cited in this month’s Energy Security Strategy to focus on unlocking the potential of hydrogen. A funding sum of up to £240m has been made available to explore the development and deployment of low carbon hydrogen production. The funding is intended to de-risk investment and reduce lifetime costs of multiple hydrogen production projects this decade to help ensure a diverse and secure decarbonised energy system that meets the UK government’s stated ambition of 10GW low carbon hydrogen production by 2030, and commitment to reach net zero by 2050.

This investment comes in advance of a declared strategic decision by 2026 on the role of hydrogen in heating buildings. This decision will consider the success of development projects that focus on appliances, such as new gas boilers that can be readily converted to hydrogen (‘hydrogen-ready’) and the testing of conversion of the gas grid. The latter in particular is critical in terms of evaluating the technical and practical feasibility of using hydrogen instead of natural gas for heating. This assessment process is also expected to consider the expected costs, benefits, impacts, and practical delivery implications.

This consultation process will also be a factor in decisions in relation to the future of broader boiler and heating system efficiency and explore the best ways to reduce carbon emissions from our heating systems

According to IRENA, the rise of hydrogen’s potential is linked to the plummeting costs of renewables and electrolysers. This greatly improves the economic attractiveness of ‘green’ hydrogen which also can help deliver on the demands for storage that comes hand-in-hand with greater dependence on wind and photovoltaic (PV) power generation. From this perspective, ‘green’ hydrogen becomes an important technology in the extension of renewable electricity developments.

Although ‘Grey’ hydrogen production, which is solely based on fossil fuels, is expected to be rapidly phased out in the coming decades, ‘Blue’ hydrogen, although also based on fossil fuels, is expected to play a complementary role to ‘Green’ hydrogen, so long as the carbon capture and storage (CCS) is proved viable. As a result, hydrogen and hydrogen-based fuels are now projected to meet a sizeable share of final energy demand in 2050, up from virtually nothing today. To achieve this in the UK, the Heating & Building Strategy report outlines the key processes of consultation required for unlocking the potential of hydrogen beyond 2026.

  • large-scale hydrogen trials: BEIS and Ofgem have liaised with the gas distribution network operators on the conducting of a ‘village’ scale deployment trial by 2025, and a possible town scale conversion project before the end of the decade.
  • Hydrogen blending in the gas grid: to develop the safety case, technical and cost-effectiveness assessments of blending up to 20% hydrogen (by volume) into the existing gas network. This has the potential to deliver up to 7% emissions reductions from the grid. The assessment of indicative cost and value of blending hydrogen is intended to be delivered this Autumn, with the possibility of a policy decision in 2023. This in particular would represent a major first step towards integrating hydrogen in the grid at a potentially national level, but would not require building projects to replace existing natural gas boilers/water heaters.
  • Hydrogen-ready boilers: Consideration will be given to the case for enabling, or requiring, new natural gas boilers to be easily convertible to use hydrogen (‘hydrogen-ready’) by 2026 (in domestic projects). This consultation would also test proposals on the future of broader boiler and heating system efficiency and explore the best ways to reduce carbon emissions from gas heating systems over the next decade. The Heating & Buildings strategy makes clearer the commercial implications where, 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.

The local trials and planning, research and development and testing outlined will help develop necessary evidence on the role hydrogen can play in the heating of buildings, enabling strategic decisions to be taken on the role of hydrogen in heating buildings in 2026. This timeframe, and the necessity of its elements, are very important to remember when the media is constantly calling for a decision to be made more rapidly. The implications of a transition to a hydrogen grid are immense, but so are the challenges. It cannot be rushed and it cannot fail if net zero is to be realistically attained, especially across the commercial & public sector built environment.

On the global stage, green hydrogen may strengthen energy independence, security, and resilience by cutting import dependency and price volatility.  However, the raw materials needed for hydrogen remain exposed to shortages and price fluctuations that could negatively affect hydrogen supply chains, cost and revenues. For this reason, hydrogen, if it is green-lit as a core contributor to the UK’s net zero delivery will not do so in isolation. Just as most buildings will currently rely on both gas and electricity, net zero ‘ready’ organisations will most likely have embraced a mixed approach. This will leverage the advantages of air source heat pumps (ASHP), proven solar thermal and natural gas with a hydrogen blend as a redundancy/peak demand back-up through the 2030s and early 40s. Hydrogen ready’’ adoption should be a necessity by the early to mid-2030’s. Then the UK could look forward to full transition to ‘Blue’ then ‘Green’ hydrogen from the late 2030s and throughout the 2040s at a national scale. Regional rollouts will of course redefine these timelines, but, if the policy supports the adoption of hydrogen from 2026, the technology usage path should remain fairly clear for commercial projects looking at unlocking the potential of hydrogen as a part of their corporate drive toward net zero sustainability by 2050.

Scenarios For Greener Buildings in the UK

Building Back Greener is the government’s campaign to improve the energy performance of buildings, reduce costs, minimise the impacts of transition on the energy system, and make switching to low carbon systems easier in order to reduce emissions and achieve net zero by 2050. Underpinning this process are three illustrative scenarios for greener buildings that reflect different technology mixes that would allow the decarbonisation of heating in buildings. The three scenarios are high hydrogen, high electrification and a dual-energy system scenario.

Today, the importance of driving these scenarios forward has been given greater urgency by the long-awaited report  from the UN’s Intergovernmental Panel on Climate Change (IPCC). To stay under the critical 1.5C threshold, according to the IPCC, means that carbon emissions from everything that we do, buy, use or eat must peak by 2025, and tumble rapidly after that, reaching net-zero by the middle of this century.

To put it in context, the amount of CO2 that the world has emitted in the last decade is the same amount that’s left to us to stay under this key temperature threshold. “I think the report tells us that we’ve reached the now-or-never point of limiting warming to 1.5C,” said IPCC lead author Heleen De Coninck. This is why quickly achieving goals towards net zero by 2050 is so important if we are to curb the worst implications of global warming – heat waves, drought & flooding.

The immediate focus from the government is to achieve Carbon Budget 6 targets, to ensure the UK is on target to achieve net zero, although many already doubt these budgets will be met as simple measures such as closing down coal-fired power stations are replaced by a far more complex mix of options that deliver more incremental steps to reducing carbon emissions. To achieve the level of emissions reductions across the built environment in line with the government’s delivery pathway to 2037, will take an estimated additional public and private investment of approximately £200 billion which will need to be focused upon one or more of the outlined scenarios.

Three Scenarios for Greener Buildings

The high electrification scenario assumes that there is no significant use of hydrogen for heating in buildings. This may be because hydrogen is not proven to be feasible, cost-effective, or preferable as a solution for low carbon heating, or because its deployment has been significantly delayed.

Under such conditions, the choice would be to continue the rapid growth of the heat pump market which the government has already seen as the best low carbon heating option for new buildings or those off the gas grid.  This would mean increasing new installations (domestic and commercial) beyond the currently envisaged minimum of 600,000 per year in 2028 to up to 1.9 million per year from 2035. Currently, the UK sees approximately 35,000 heat pump installations per year, and commercial demands are already outstripping available stocks in the market as a result of raw material and component shortages caused by Covid.

To ensure the extended level of heat pump deployment, further policy would be required to phase out installation of new fossil fuel heating faster while continuing to follow natural replacement cycles. The proposed increased deployment of heat pumps will need to be accompanied by investment in the infrastructure needed to meet increased electricity demand, including the generation of low carbon electricity and additional grid capacity.

If hydrogen proves both feasible and preferable as a method for heating most UK buildings, and decisions taken in 2026 support a path to converting most of the national gas grid to hydrogen then the high hydrogen scenario would take effect. Pilot projects to provide heating for an entire town by the end of the decade would, once successfully implemented, see an accelerated rollout on a national scale. The conversion would likely start by building out from existing hydrogen production and use in industrial clusters, and roll-out would involve switchover on an area-by-area basis in different locations.

Due to the infrastructure and supply chain requirements of a hydrogen conversion the government estimates new heating system installations should be low carbon or hydrogen-ready, meaning ready for a planned future conversion, from 2035, with approximately 30% of existing low carbon buildings to be supplied by hydrogen at that time.

This does mean approximately 53% of buildings with low carbon systems would be reliant on heat pumps and 15% heat networks. This is why the third, and most realistic of the scenarios for greener buildings is one based around a dual-energy system, where both hydrogen and electrification prove feasible and preferable for heating buildings with a widespread demand for hybrid systems that utilise a mix of energy sources.

For example, if all, or most of, the gas grid is converted to low carbon hydrogen, but the costs and benefits of switching to hydrogen versus installing a heat pump are viewed differently by organisations we might see a high switchover to both hydrogen and heat pumps on the gas grid. Based on differing geographical or built environment factors, there may be a partial, but still extensive, conversion of the gas grid to hydrogen. Under this latter scenario, more careful consideration would be required of which parts of the grid would be converted and where responsibility for decisions about the costs and benefits of converting different areas should lie.

While the government claims it remains early days in terms of determining the policy framework that might support this mixed transition, global conditions, both political and environmental, are driving fresh demands on the government to accelerate commitments.  Any scenario in which hydrogen is an available option from the grid will require public policy decisions to enable cost-effective and coordinated investment in infrastructure and supply chains. If the case for converting the network to hydrogen differs strongly from area to area, more preparation may need to take place at a regional or local level.

What does this mean for the commercial sector?

Whichever scenario becomes the one of choice, you can expect greater consultation over new regulatory powers that can be brought to bear on the commercial sector to bring it into alignment with the government’s goals for delivering these scenarios for greener buildings.

Initially expect to see the phasing out of heating appliances that are only capable of burning fossil fuels. This would be consistent with the ambition to phase out the installation of new and replacement natural gas boilers by 2035, and the phasing out of the installation of high-carbon fossil fuel boilers in commercial properties not connected to the gas grid by 2024.

The government’s Energy White Paper has already set a minimum energy efficiency standard of EPC Band B by 2030 for privately rented commercial buildings in England and Wales. And you can expect further consultation on regulating the non-domestic owner-occupied building stock and consideration on whether this should align with the private rented sector minimum energy efficiency standards. There is also an expectation for a response to the 2021 consultation on introducing a performance-based policy framework in large commercial and industrial buildings, with the aim to introduce a pilot scheme sometime in 2022.

Further consultation is expected on the Small Business Energy Efficiency Scheme (SBEES). This scheme aims to remove barriers for SMEs in accessing energy efficiency measures, drive forward better buildings performance and aid SMEs in meeting regulatory standards.

Finally, you can also expect to see a strengthening of the Energy Savings Opportunity Scheme (ESOS), which is a mandatory energy assessment scheme for large businesses’ energy use and opportunities to improve energy efficiency.

What is very clear at this stage is that commercial organisations face a complex technical and regulatory challenge in the coming decades if they are to successfully navigate to a future with decarbonised buildings across their estates.   Consulting with expert providers at the earliest planning stages can pay dividends in the longer term, balancing the use of cost-effective and familiar technology now with new developments in the mid-to-long term. From a business perspective, the advantages of decarbonisation can be valuable in terms of operational savings and corporate social responsibility gains, but higher capital and operational expenditure also need to be considered if realistic steps are to be made. With more than 50 years of experience delivering bespoke commercial hot water and heating applications and deep knowledge of renewable systems,  including both heat pumps and solar thermal, Adveco is perfectly positioned to advise and assist organisations seeking to begin the decarbonisation process now.

MD wall hung boiler & ATSH indirect water heater

DHW For Smaller Businesses

Refurbishing and modernising heating and domestic hot water DHW for smaller businesses should not be a chore, but commercial boilers can be large and complex to install, especially if available space is limited for new plant. Adveco has responded to this, extending its award-winning MD boiler range with a series of highly compact wall hung variants designed with the smaller plant room in mind.

Smaller business types, from office buildings to light commercial industry, retail and cafés will typically exhibit defined periods of continuous heating and hot water demand across the working day, often encompassing peak periods of demand when energy costs can also be higher. For this reason, to ensure demand is met and energy costs offset, commercial applications will typically look to incorporate thermal storage through indirect heating, using the boiler as the primary energy supply. This is advantageous in terms of maintaining consistent levels of heating or hot water throughout the day, as well as being able to rapidly respond to fresh demands for extra heating. The size of such a system can however prove prohibitive for smaller businesses. While the MD range offers a variety of models to address central heating needs,  Adveco’s MD 15B, 24B and 34B feature connections specified for use with an indirect water heater that can also be used to provide DHW for smaller businesses.

The MD boiler’s single, high-quality patented titanium-stabilised stainless steel heat exchanger, provides 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 for improved operational efficiency and extended operational life. This is further improved by separating the water flowing through the boiler from the business’ DHW supply which is achieved by pairing with an indirect hot water calorifier, such as the extremely compact 160 and 200 litre ATSH Stainless Steel High-Capacity Cylinders. The calorifier vessel includes a single internal high-capacity fixed heating coil at low-level for use with the high-powered MD heat source and adds the option of a secondary electric immersion for built-in system redundancy.

One of the greatest advantages of using this type of indirect tank with an MD Wall Hung Boiler is the consistency of DHW for smaller businesses without requiring the boiler to be in constant use. You, therefore, save on energy, further reducing emissions and are better able to control operational costs. The boiler efficiently heats the water in the tank, which is kept at a consistent temperature for a near-instantaneous supply of hot water as and when needed, steadily distributed throughout the day. Rapid thermal recovery means the system is able to support even the most demanding peak periods which are easily addressed by the built-in controls accessed from the MD’s LCD control screen.

Should business demands increase consistently, the MD is designed with cascade control to enable up to eight units to work together seamlessly, and the ATSH range of calorifiers offers larger vessel sizes for extra DHW load.

Whether providing space heating or DHW for smaller businesses seeking an efficient, cost-effective replacement for ageing gas-fired boilers to support your application, the Adveco range of MD wall hung boilers offer a wide choice of appliances to meet your particular business needs without the need to oversize a system which will be more costly to both install and operate over its lifetime.

Public Sector Decarbonisation Of Hot Water & Heating

Public sector decarbonisation is a core facet of the government’s Heat & Building Strategy, which has been published to outline how the UK can achieve net zero by 2050. By decarbonising public sector buildings, the government aims to demonstrate leadership and to encourage action in other sectors to make a direct contribution to net zero.

With around 40% of UK greenhouse gas emissions being accounted for by heating, cooling, and lighting the built environment, the government has said it is ‘essential that the public sector demonstrate leadership and drive down emissions by using credible and consistent approaches to decarbonise the public sector estate.’ The aim is to reduce direct emissions from public sector buildings by 75% against a 2017 baseline by the end of carbon budget 6.

Addressing decarbonisation within both new construction or refurbishment of existing properties has now become a key deliverable throughout the public sector which will need to be shown to be leading the way in decarbonising UK buildings in the 2020s.

What is the government doing to support the public sector?  

The government’s £1 billion Public Sector Decarbonisation Scheme was initially announced in 2020 to provide funding until this year. Conceived to support the public sector in finding answers to heat decarbonisation additional funding was allocated to make public buildings greener and the second phase of the Public Sector Decarbonisation Scheme was launched last April with an additional £75 million of funding into this year. The government has subsequently committed to investing a further £1425 million for the Public Sector Decarbonisation Scheme between now and 2025. This funding is intended to provide public sector organisations with grants to fund energy efficiency and heat decarbonisation measures and supports the decarbonisation of the public sector in line with the government set net zero targets.

The funding will aim to deliver energy efficiency and heat decarbonisation improvements to organisations such as schools, hospitals and public sector offices, and present an opportunity to build wider support and acceptance for transformation of how the UK heats buildings. The government has stated it is committed to the continuation and extension of the scheme to “ensure that public sector bodies have access to finance to continue decarbonising their estates.”

What does the government expect of the public sector?

The government’s aim is to introduce greater transparency into how the public sector is making practical changes to achieve decarbonisation. At a basic level, the expectation is for “all public sector organisations to be thinking about how they will achieve Net Zero and should be taking steps to start this process now.” As publicly-funded organisations, they should expect to be held accountable to the public by reporting their progress. Through the Greening Government Commitments (GGCs) a framework for reporting against targets to reduce public sector greenhouse gas emissions has already been set in place, and now all public sector organisations will be expected to show leadership by taking steps to reduce direct greenhouse gas emissions. This should include monitoring their energy use and setting targets and plans to reduce emissions over the next five years. Different targets will be appropriate for different organisations, but all public sector organisations are expected to publicly report progress against their plans and targets.

The Heat & Building Strategy specifically calls on public sector organisations to plan to reduce direct emissions from their heating systems by making buildings more efficient. This should be achieved through:

  • improving building insulation
  • switching to low-carbon heating sources when it is time for heating systems to be replaced
  • implementing smart technology
  • installing low-carbon heating in new buildings, which means retrofitting will not be needed

If reporting of public sector emissions on a consistent and coherent basis is not done on a voluntary basis, and, if insufficient progress is made on reducing emissions in the public sector, the government will consider legislation requiring all public sector organisations work toward and report against a legally binding target to reduce their greenhouse gas emissions.

How can Adveco help?

The Heat & Building Strategy accepts that public sector organisations will require new specialist skills and expertise to decarbonise, both through making infrastructure improvements and by better managing operational energy use. As the public sector provides all public services, including education, healthcare, emergency services and social care to name a few, these organisations encompass a large and varied requirement for hot water and heating.

Including everything from showers, washbasins and kitchens, to varied space heating demands,   applications will vary dramatically across each bespoke case, making decisions on decarbonisation all the more complex and difficult without specialist support.

Currently, the government favours air source heat pump (ASHP) based applications for the public sector as the simplest and most cost-effective answer to being greener. But many have queried the expense and relevancy of the technology outside of new build properties. The Government has said it will work with the industry to help meet the goal of reducing ASHP cost, bringing them in line with current fossil fuel options by 2030, ‘with big cost reductions of between a quarter and a half by 2025 expected as the market expands, and technology develops.’

This and the practical benefits of switching to high-efficiency heat pumps to reduce energy consumption, which includes less CO₂ production and lower long-term operational costs, make the technology an important part of the process for achieving carbon-neutral goals on schedule. The high-temperature demands of commercial hot water systems do however curtail the current generation of heat pumps as a singular response, with existing, poorly insulated buildings further reducing efficiencies. For this reason, public sector organisations faced with delivering decarbonisation goals within the proposed next five year period will need to consider more complex hybrid systems, or if on gas, look to solar thermalas a practical way to reduce energy use and decarbonise their buildings.

There are a number of available responses and new lower-carbon technologies are under consideration by the government for further support but knowing what is best for your organisation is not always straightforward. Faced with varied building stock, technology options and fluctuating user demands for hot water and heating consulting with Adveco’s expert sales and engineering staff can help you truly understand those needs and the options best suited to your bespoke situation.

Discover more about Adveco’s renewable systems for decarbonising your building hot water and heating.

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.

Is A Calorifier The Right Choice For My Project?

Today we take a look at commercial-grade indirect-fired water heaters, and ask is a calorifier the right choice for your hot water or heating system?

A calorifier is a commercial-grade indirect-fired water heater that provides hot water in a heating and hot water system.

It is designed for projects requiring large volume storage of water at high temperatures, but rather than using a burner, the water is heated by heat exchanger coils containing liquid from another heat source, such as a boiler.

In a typical application, the hot water directly heated by a gas or electric boiler passes through the calorifier and is used, via heat exchange, to heat up the cold water in a separate system of pipework. This does mean that a calorifier cannot react as quickly to demand as a direct-fired water heater, however, with the calorifier working as a buffer and storing the hot water, it reduces the operational demand placed on the boiler. With the boiler no longer required to work as hard to meet the domestic hot water needs (DHW) of a building, energy is saved, costs are reduced and emissions fall.

With the increased efficiency of modern condensing gas boilers, having a dedicated hot water boiler to heat the calorifier is no longer a requirement as they can easily supply heat to both the calorifier and the heating system. The compact Adveco MD range of gas condensing boilers, for example,  are both high capacity and can be arranged in cascade to scale to provide both heating and, with an indirect calorifier, the DHW needs of a wide variety of commercial projects. It must be noted that when space heating is not required, such as during the summer months, the boiler will still be required to provide heat for the hot water system.

FUSION Hybrid Hot Water System File: ATSH cutaway. Another advantage of the indirect approach to heating 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. At Adveco, these options are supported by a variety of calorifiers. The Stainless Steel Indirect (SSI) range, for example, is supplied with a single high-output internal heat exchange coil at a low level to serve as an indirect calorifier in DHW installations. The ATSx range provides water heaters designed to be used with indirect heat sources as calorifiers across a range of DHW installations exhibiting smaller demands but requiring more than six bar pressure. For more complex and renewable-based systems, the Stainless Steel Twin-Coil (SST) or ATSR ranges offer a pair of independent internal heat exchange coils to serve DHW systems. Each high-output coil can be used with a separate heat source, enabling effective integration of renewable technologies or multiple heat sources, or alternatively can be combined to increase the heat transfer capacity from a single high-output source.

Also, by separating the supplies you reduce the risks of external contamination, a build-up of scale in hard water areas or the corrosive effects of soft water.

Calorifiers are also simple to install. Since there is no burner, there is no need for the gas supply to be directly connected to the appliance and the is no requirement for a flue.

So is a calorifier the right choice?

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 calorifier within a hot water system gives you a number of design options, as a larger calorifier means the boiler can be smaller, or the reverse if the existing system has a large efficient boiler. Understanding the hot water demand is critical. If demand is not so great, then using a larger calorifier can lead to unnecessary capital and ongoing operational expenditure. Go too small and the storage could prove inadequate and the system will not achieve its operational requirements.

Attaining the correct balance of demand and efficient, cost-effective supply is what ultimately defines a successful system, whether it be for a hotel, hospital, school, office or leisure facility. Each will have its own parameters to be met, and Adveco specialises in providing the widest range of calorifiers, boilers and renewables to meet the bespoke needs of any project.

The patterns of hot water usage and recognition of periods of peak demands often make sizing a complicated process, with many systems overcompensating and, by being oversized becoming more costly and less efficient. At its simplest, a commercial system should hold an hour of hot water output in storage, but the function of the building, its population and activities will adjust requirements, for example, where hospitals will typically exhibit a 24/7 demand for hot water, schools and offices may be limited to just 7½ hours per day. In some refurbishment scenarios, we will also see a physical limitation of space available for DHW storage, in which case a system will put more demand on the boiler or renewable to increase the output for preheating, reducing the required size of the calorifier.

If there is an availability of space, or a prefabricated packaged plant room approach can be used to relocate plant to previously unused space – such as a rooftop or car park – there is an opportunity to incorporate multiple calorifiers and thereby divide the total storage demand. This approach not only provides system resilience, but for commercial sites that exhibit predictable seasonal demands such as leisure centres, campsites and hotels, it allows for elements of the system to be shut down during off-peak periods. The other real advantage of adopting a packaged plant room approach to a DHW system is that the boiler or ASHP providing the preheat can be located in close association with the calorifier. The physical proximity helps negate problems of heat loss between the boiler, pipework and calorifier which can be detrimental if more widely separated in a system.

Is a calorifier the right choice for your project? If it is, the technical details of our products can be found here buffers and calorifiers and find out how we can help size your DHW application.

NOx On Effect

A major contributing factor to poor air quality, nitrogen oxides are a group of gases that are mainly formed during the combustion of fossil fuels. The dominant portion of these gases is nitric oxide (NO) which in turn can react with other gases in the atmosphere to form nitrogen dioxide (NO) the most toxicologically significant of the nitrogen oxides.  These reactions take place very quickly and are reversible, so the two gases are referred to together as NOx. Short-term exposure to concentrations of NO can cause lung irritation and respiratory infections, but medical studies have also linked the gas to cancer, asthma, strokes, and heart disease. In addition, NOx can cause changes to the environment, so consideration should be given to its control as part of your organisation’s sustainability activities.

Typically, a by-product of the combustion of hydrocarbon fuels, it is especially problematic in city centres due to idling traffic. In large parts of the UK, the atmospheric levels of NO are considerably higher than European legal limits and the Royal College of Physicians believe it directly leads to as many as 40,000 deaths each year with an estimated cost to the country of £20 billion in healthcare and lost working days.

Critically as greater political and legal weight is brought to bear on addressing climate change it is worth remembering that nitrogen oxides also act as precursors for the formation of ozone, which is not only damaging to health but has adverse effects on the environment through oxidative damage to vegetation. Introduction of N to the environment both directly as a gas and in precipitation can also change soil chemistry and affect biodiversity.

This has led to widespread recognition that more needs to be done to address the issue of NOx, from transport to energy production, distribution, and consumption in buildings.

Traditional energy generation by coal, gas and oil-fired power stations comes with several issues, including being NOx heavy. It, therefore, became popular to look at the alternatives: renewables which help with both carbon and NOx emissions. As such, low carbon electricity’s share of generation has risen delivering a major shift away from generation in large power stations. Since 1990, wider industrial emissions of nitrogen oxides to air have reduced by 74%, although estimates of projected emissions to 2030 suggest further action is required if we are to meet government emission reduction targets. These industrial reductions mean that most of a city’s current air pollution and NOₓ now arise from road traffic and buildings.

The most recent published annual air quality assessment providing data from 2010 until 2019, shows the UK was in compliance with commitments to current emission ceilings for nitrogen oxides. However, the UK continues to be non-compliant with the limit value placed on the annual mean NO concentration at several locations in urban areas. At these locations, it has been estimated that up to 80% of the NO concentration originates as NOx emissions from road transport. But buildings still stand as a key potential contributor to the other 20%.

Managing NOx Emissions From Commercial Properties

In 2018, the European Union’s Energy-related Products Directive (ErP) was used to begin phasing out the installation of less efficient equipment across Europe, including the UK. This would be achieved by establishing minimum performance standards for new equipment, with greater focus placed on heating and water heating performance in buildings. The new ErP directive enforcing maximum NOx emissions from boilers and water heaters which were set at 56mg/kWh for gas/liquefied petroleum gas (LPG) and 120mg/kWh for oil-fired products. At the time the EU predicted the new directive would produce a 20% reduction in energy consumption and emissions when replacing older equipment with ErP-compliant products

The drive towards net zero and the reduction of carbon in buildings is helping to further drive down NOx and where new builds are opting for heat pump and direct electric hot water and heating applications gas to the premises is excised. So no gas, no flues, no NOx. Refurbishing existing properties is more complicated, with low-temperature Air Source Heat Pump (ASHP) based systems typically unable to efficiently address demands. Under these scenarios, a combination of solar thermal and gas top-up for water heating is preferable and leaves sites futureproofed for next-generation green gas technologies. Realistically hydrogen grid connectivity is unlikely for the majority of the UK until the mid-2030s at the earliest, so attention needs to be applied to how gas-based systems can be optimised now to reduce emissions to levels even lower than those established under the ErP directive.

To improve combustion efficiency, condensing gas water heaters and boilers operate so that the water vapor in the exhaust – which contains about 464 kJ/kg of latent energy – condenses on the heat exchanger and not in the flue or outside the building. Designed so that the highest efficiency is at the low end of the firing range, condensing boilers typically operate at 94-95% combustion efficiency. Correctly sized and professionally commissioned, a cascade system for larger demands with high-efficiency pre-mix burners provides a high 1:20 modulation ratio. This large modulation range, along with built-in cascade control ensures that efficiencies are maximised no matter the heating load of the building. With the input of the appliance easily altered to closely match the load, the system is better able to derive as much heat out of the exhaust gases as possible.

With a high-efficiency pre-mix Fecralloy burner, such as employed in the Adveco MD & AD product ranges, ideal combustion efficiency can now be achieved of up to 107% (net)/98% (gross) reducing energy costs and producing ultra-low emissions. The low CO (19ppm) and NOx (27mg/kWh) emissions, from a hot water system built around a high efficiency condensing water heater or boiler (Class 6 appliance) easily satisfy the requirements of the current Energy-related Products (ErP) directive.

In the drive to achieve net zero, and control dangerous emissions, there remains a clear need to address legacy ‘dirty’ buildings. Currently ignored in terms of mandated policy or government support, commercial building refurbishment represents a core challenge for the UK’s climate future. Organisations looking to make steps towards a more environmentally friendly built environment may initially reject any fossil fuel-based option, but the reality is modern systems are advantageous both economically and environmentally and they bridge towards more enveloping carbon neutral and renewable options. If your building’s hot water or heating system predates 2018 then there are advantages to be gained from switching to the latest generation of gas-fired water heaters and boilers, if your system is closer to 15 or 20 years old then you really should be giving serious thought to upgrading appliances. The addition of solar thermal preheat is then going to take your system to the next level in terms of cost and carbon reduction into the 2030s and beyond.

Balancing Commercial Gas Heating & Sustainability

When it comes to specifying commercial gas heating,  COP26 has heightened awareness for the need to reduce fossil fuel consumption, and with most of the national infrastructure currently ‘on gas’ and delivering half of the UK’s non-transport primary energy needs, building owners and operators will be looking at their options.

For older properties that account for a high proportion of the existing commercial building stock, a transition to all-electric applications, or implementing effective use of heat pumps, can represent a costly, technical challenge. As such, many will be looking to hydrogen alternatives. But with a government decision on the technology not due until 2026, its’ usage, if supported nationally, will take time to become commonplace. As such natural gas-fired boilers will, for the time being, remain a preferred option for the provision of commercial space heating, so how can this help drive sustainability into the built environment?

Increasingly stringent legislation aimed at reducing carbon emissions and hazardous air pollutants is already driving the specification of systems that are based on high efficiency condensing boilers, or a hybrid approach that combines these boilers with heat pumps to provide low carbon, effective heating.

The cost-saving functionality of high-efficiency condensing gas boilers can be readily demonstrated, but what of the air quality and sustainability of the technology?

Commercial Gas Heating – Sustainability & Air Quality

Adveco’s MD boiler range, for instance, has been designed so that the highest efficiency is at the low end of the firing range, condensing boilers typically operate at 94-95% combustion efficiency. MD’s high-efficiency pre-mix burner can achieve ideal combustion efficiency of up to 107% (net)/98% (gross) reducing energy costs and producing low emissions. With low CO (19 ppm) and NOX (34 mg/Nm³) emissions, a heating system built around a high-efficiency MD condensing boiler (Class 6 appliance) easily satisfies the requirements of the Energy-related Products (ErP) directive when specifying commercial gas heating in a building.

Adveco’s MD boiler range, for instance, can be used to create a cascade of up to eight 280 kW units, each combining four 70kW heat engines pre-stacked in a single, elegant casing. This approach can provide more than 2200kW while occupying minimal plant room floor space. Correctly sized and professionally commissioned, such boiler cascade systems with high-efficiency pre-mix burner can provide a high 1:20 modulation ratio. This, along with built-in cascade control ensures that efficiencies are maximised no matter the heating load of the building. With the input of the boiler easily altered to closely match the heating load, the system is better able to derive as much heat out of the exhaust gases as possible. This efficient reuse of heat also results in low flue gas temperatures allowing for the use of standard 80-160mm diameter plastic flue pipe (PP). PP is efficient, environmentally friendly, and significantly cheaper than stainless steel, offering a cost-effective and space-saving alternative in terms of pipe run.

For commercial projects that face the most stringent legislation and oversight, high-efficiency condensing boilers remain a realistic and effective means of meeting the demands for improved building sustainability. Especially if used as part of a hybrid system where continuous low-grade heat from the heat pump works alongside the fast responsiveness of the gas boiler to top up the heating at electricity peak demand times, thus avoiding the requirement for higher carbon-emitting generators. Crucially, and despite recent price fluctuations, gas continues to offer considerable economic advantages in terms of operational costs for built assets. We currently would still therefore advocate a modular cascade concept. This takes full advantage of the compact size afforded by condensing natural gas boiler technology, such as the MD, with its low-water content heat engines, and built-in redundancy. The latest generation of condensing gas boilers represent a familiar, reliable response to a building’s heating demands that dramatically improve on the efficiency of older boiler technology to deliver immediate emission reductions. Critically this approach retains the infrastructure necessary for the introduction in the next decade of green gas variants with all the promises of much lower carbon emissions that will carry the commercial sector towards the national net zero goal by 2050.