Posts

Navigating Regulations & Application Design for Commercial Hot Water Systems

There are huge expectations placed on building services engineers and sustainability consultants to be experts on the regulations for the built environment and the ever-developing technologies employed to meet them. The most important systems and features of the building, such as its fabric, power, heating and cooling systems are well understood and can be confidently dealt with when specifying and delivering a project. Designs including non-traditional and secondary systems are where engineers can be at a disadvantage due to the vast amount of changing information that they need to know. These systems can include domestic hot water (DHW), renewables plus the control of them, and gas appliance flueing.

These secondary systems on commercial projects are therefore a perfect opportunity to lean on more specialist application design services so that consultants can place their focus on the mainline elements of a building project. At Adveco, we have supplied specialist design support for the past 50 years, ensuring typically bespoke applications meet regulatory demands and best practice to sensibly manage capital expenditure while ensuring system longevity for better operational life.

In recent years we have come to recognise three prime ways that specialist application design becomes truly advantageous to a commercial building project. The first is in supporting mechanical and public health engineers deliver comprehensive and highly efficient DHW systems. The second is aiding sustainability consultants in the integration of renewables. The third is in helping engineers and D&B contractors to address the complex regulations surrounding the installation of flues for gas-based systems.

With DHW applications the primary issues are always going to relate to correct sizing based on the demands generated by a building’s occupants and choice of system. These can be based on application, energy source, suitability, and integration with carbon saving technologies,

Oversizing DHW systems inherently come from a lack of understanding of hot water demands within the building, diversity, and length of the peak period. Oversizing is exacerbated by the false belief that the building uses more hot water than it really does, and an attitude of ‘better too much than not enough’. Sizing programmes, often employed for a quick sizing early in the design then never reviewed, do not deal well with the many variables and decisions on diversity leading them to oversize to prevent hot water problems. Traditionally the problems with oversizing, such as increased standing losses, increased outlay costs, increased pipe sizes, and increased space use may have been minor in terms of the cost of the whole building, but it now has another important knock-on effect. If the hot water consumption is overinflated, it falsely increases the expectation of the building’s carbon emissions. This then requires greater employment of renewables to reduce emissions which do not actually occur. This can come at great cost and complication and provide little benefit to the building. Access to realistic sizing tools and having the experience to interpret results requires both expertise and time, which specialist application design can bring to a project.

The integration of renewables, such as air source heat pumps (ASHP), heat recovery and solar thermal, will further increase the complexity of a system. Renewable technologies are going to be selected early in the design process to secure the Part L approval, once modelled successfully it is not wise to start changing things too severely. Small changes, such as revising the manufacturer of an appliance is going to make little difference within Part L, but if you have to add, remove and replace a technology, then you are going to be back at the beginning, and will almost certainly need to resubmit your Part L calculations. These early selection decisions increasingly reside with the sustainability consultant before the design engineer is involved, which means they need a broad knowledge of building services systems beyond the renewables themselves. Working together with specialist application design means they can better advise on selecting the right type of renewable to ensure it will integrate with the rest of the system and be controlled to work with traditional technologies. It is very important that renewable heat sources, particularly those that provide low-grade heat, are not held off by traditional boiler systems providing high-grade heat to high-temperature systems. This is not purely a controls issue but one that requires an in-depth understanding of the complete system arrangement to set it up effectively.

Finally, a regulatory issue that continues to impact consultants, engineers and D&B contractors has been the change to flue and gas standards.

IGEM/UP10 Edition 4 is an Institute of Gas Engineers and Managers utilisation procedure which attempts to address two major points of confusion: safe horizontal termination and the definition of a group of appliances. Adveco applies this document in all relevant plant room design since limits on horizontal termination through a wall terminal at low level is clearly important from a safety perspective. Many designers and installers remain unsure how to apply it correctly which can have a major impact on commissioning if the termination is not found to meet the current regulations.

Under UP/10, groups of terminals are defined by a mathematical formula which sets a corresponding dimension. Terminals that are within the calculated dimension of each other are k,89a group regardless of type or location. A group of terminals with an input over 70kW (net) that terminate horizontally must now be tested against a risk assessment provided within UP/10; this could therefore include terminals from appliances with outputs below 70 kW that previously would not have been considered if their terminals conformed to BS5440. The IGEM procedure will potentially allow up to 333kW (net) to be exhausted at low level if it is deemed risk free (such as a windowless wall looking over open fields) but will not allow 70kW to be exhausted at low level if deemed unsafe (such as an internal corner, or adjacent to openable windows, walkways, or a playground). Despite holding British Standard (BS) equivalency and being published for more than five years, UP/10 remains underused in the early design phase where it should be used to determine when flues must terminate at high level so that they can be included in the installation budget.

Faced with an ever-widening range of technology and regulations, access to a specialist design for these secondary systems is an extremely useful asset, one that can be both an independent sounding board and an extension of the in-house design function. That saves valuable time, delivers a better project specification and helps avoid problems that can halt final commissioning of a system, delaying or even preventing a building’s final handover to the new resident.

Enquire about sizing your project 

UK needs to cut emissions by 78% by 2035 to meet net-zero

Under the original Climate Change Act, the UK pledged to cut net emissions by 80% by 2050. Now, it will need to deliver a 78% reduction by 2035 if it is to meet its long-term net-zero commitment. That is according to the Climate Change Committee (CCC), which has published its Sixth Carbon Budget for the period between 2033 and 2037.

The CCC described the budget as the toughest yet with chief executive Chris Stark saying that the UK will need to decarbonise at a faster pace in the next 30 years if the net-zero target is to be met. Stark explained that the Committee has deliberately opted to ‘front-load’ decarbonisation – more will need to happen in the 2020s and the earlier half of the Sixth Carbon Budget period than in the latter half and the 2040s. Heat, and the broader decarbonisation of buildings, is one of the major priorities identified by the CCC which has based its calculations on a scenario in which 40% of the emissions reductions needed will be delivered using pure-technology solutions.

The new recommendations will see heat supply drastically transformed from its current reliance on natural gas if the country is to decarbonise all aspects of the UK’s infrastructure and economy. The budget has set a mandate for fossil fuel boiler installations to end across the UK entirely from 2033, with fossil fuels phased-out from heating in public buildings by 2025 and in commercial buildings by the following year. It added that these stricter targets to phase out higher-carbon technologies in public buildings would also support a government aim of realising a 50% reduction in emissions by 2032. The 2033 date has been set to take account of the typical 15-year turnover of boiler stock, while also allowing for the scaling-up of supply chains to deploy heat pumps at a mass scale.

The recommendations aim for 37 per cent of public and commercial heat demand to be met by lower-carbon sources as of 2030.  According to the CCC, heat pumps should cater for 65% of the predicted need, 32% of heat should be provided by district heating systems, whether low or high-temperature supply, with a further 3% from biomass by the end of the current decade. By 2050, CCC estimates that 52% of heat demand should be met by heat pumps, 42% from district heat, with hydrogen boilers covering the remaining 5% of national demand.

One caveat, however, was that since the dates operate alongside the deployment of low-carbon heat networks and planned regional rollouts of hydrogen conversion of the gas grid, the phase-out outlined may not apply in any areas designated for these alternatives. This makes a nod to a net-zero that derives balance between pure hydrogen systems and electrification, both delivering decarbonisation of heating. It also highlights the danger of supporting one technology and ignoring another when the pace of development is so much steeper and will continue to be so as we move towards 2050. To this end, the CCC is using what it describes as a ‘balanced pathway’ scenario upon which to base its calculations and that its delivery will require ‘systems change’ and a ‘whole economy approach’ to decisively meet the UK’s legal target of fully eliminating and offsetting carbon emissions by 2050.  Under this ‘decisive’ decarbonisation plan, the CCC has warned that a sizable majority of change must be made within 15 years.

Talk to Adveco about how we can help you create more sustainable heating and hot water applications for your buildings.

Non-domestic RHI gains 12–month extension

Originally set to finish at the end of March 2021, and in response to delays caused to building projects by COVID-19, the Government’s non-domestic Renewable Heat Incentive (RHI) has received a 12-month extension. In response to concerns raised by stakeholders that a significant number of existing projects would fail to meet the scheme closure application deadline of 31st March 2021, affected projects are now able to submit an extension application.

Those existing projects unable to commission and accredit to the scheme before the previous deadline now can extend these processes until 31 March 2022.

With increasing pressure to decarbonise in line with the Government’s ambitious net zero targets, the preservation of reliable and continued funding for the commercial sector is critical if organisations are to be further encouraged in the adoption of future-proof sustainable developments. With no clear, immediate replacement for the RHI, concerns had been raised regarding the lack of incentivisation for the commercial sector, as new schemes focussed on domestic installations. Given around 40% of UK greenhouse gas emissions are accounted for by heating, cooling, ventilation, the provision of hot water and lighting the built environment, and some 17% is generated by commercial building stock, it is clear that more help is required to drive the uptake of renewables and more sustainable systems if the UK is to achieve climate-neutral buildings by 2050.

Designed to provide financial incentives to increase the uptake of renewable heat by businesses, the public sector and non-profit organisations, the non-domestic RHI is currently applicable to air source heat pumps, such as the Adveco FPi range and L70, and solar thermal for commercial uses including large and small businesses, plus schools and hospitals. Administrated by Ofgem on behalf of the Department of Energy and Climate Change (DECC), tier one of the RHI incentivises non-domestic energy producers for either the life of the installation or 20 years as a maximum. If conditions are met, with equipment, including a generation meter, being installed by a microgeneration certification scheme (MCS) accredited installer, eligible businesses in England, Scotland and Wales will now continue to be paid for installations completed and commissioned before 2022.

Once successfully accredited, systems will receive quarterly payments per kilowatt-hour (kWth) of energy use, however, if metered as a multiple system, which includes either ASHP or solar thermal and a gas boiler, then payment is made purely for the heat generated by the heat pump or solar thermal aspect of the application.

The current 2020/21 (non-domestic) tariff are:

  • For new air source heat pumps – 2.79(p/kWh)*
  • For new solar thermal collectors less than 200kWth in size (tier 1) – 10.98(p/kWh)*

For specifiers and developers installing renewable heating systems on commercial buildings or small-to-medium-scale district heating projects, the extension also provides crucial financial support ahead of the Green Heat Network Scheme (GHNS) coming into force in April 2022.

*For more information on non-domestic RHI and the full conditions of eligibility, refer to the energy regulator Ofgem.

Making Air Source Heat Pumps (ASHP) Work For Commercial Applications - Part 1

Making ASHP Work For Commercial Applications – Part 1

Understanding the Challenge of ASHP

Commercial organisations face a somewhat unfair challenge as they are held by the Government to be leaders in the move to control and reduce carbon to achieve net-zero by 2050, yet are limited by the technology options that the Government is showing active support for. The current drive, without a doubt is to push Air Source Heat Pumps (ASHP) to the exclusion of other technologies. Neither high-efficiency gas boilers with ultra-low emissions nor proven sustainable systems such as solar thermal have received much love in the latest round of grants supporting the commercial sector. In particular, the decision not to provide support for those opting for hybrid solutions that bridge the technology gap in the most cost-effective manner shows a focus on the finish line, but a failure to grasp the actual challenges the commercial sector faces right now. So, what are the options with ASHPs, and what is a realistic path to take today?

Unfortunately, we cannot control the weather, but despite that, ASHP technology does still present an opportunity to significantly improve the efficiency of buildings across the commercial sector. Because an Air Source Heat Pump is reliant on the ambient air, the Coefficient of Performance, or COP, is going to be affected by both the source and supply temperatures. The heat provided is at a much lower temperature, so a heating system will be required to operate at low temperature for optimum efficiency and may have to be kept on for a longer period to be fully effective. Such a system could well require a significant upgrade to a building’s electrical supply and heating infrastructure. However, to maximise the ASHP efficiency, the lowest possible flow temperature needs to be achieved, and that requires a building to be highly efficient in terms of heat loss. When working with new builds, the ability to drive high efficiency in the thermal performance of the fabric of a structure means a well-designed commercial heat pump system is more than capable of providing all the heating needs for a business and, in the long term, represent good value for money in savings from reduced energy bills, as well as helping commercial premises bring down that all-important carbon footprint.

But in isolation, this demand for low heating temperatures and low water usage will be impractical for many businesses, especially when retrofitting a property, which can highlight the limitations of ‘pure’ ASHP systems. This becomes particularly obvious when ASHP is to be deployed for the provision of hot water, especially if there is a large daily demand. Domestically we would expect a minimum storage temperature of 50oC, but this rises to 60oC minimum for commercial environments. This has a considerable impact on the ASHP’s running efficiency and therefore the running costs. Additionally, by generating hot water at 50oC and not 70oC, the storage volume will have to be considerably larger than that associated with a typical gas boiler. To achieve necessary water temperatures requires greater considerations of space planning and type of hot water cylinder the system will require.

With early to market performance of heat pumps falling below expectations, and a higher capital cost relative to the conventional gas boiler alternative the uptake of ASHP in commercial business on the gas grid had, until the drive to achieve net-zero, been limited. Now commercial operations are actively seeking to use ASHP, but are still running up against these same issues, which is why, with the current capabilities of ASHP technology, a hybrid approach for commercial applications remains attractive. Both in terms of installation and operation, whilst still gaining the all-important running cost savings and reduced carbon emissions.

In part 2 we explore how a hybrid approach can deliver significant value from ASHP technology

Read about Adveco’s compact commercial FPi ASHP range

Planning Change Ushers In Restaurant Refurbishment Challenge

From the beginning of September 2020, changes to planning will see use classes A1 (shops), A2 (financial and professional services), A3 (restaurants) and B1 (offices) merged to create a new Class E. This will enable use of these spaces to be altered from one use to another or undergo change to multi-use venue without seeking consent from local authorities.

The simplification of planning creates several fascinating new opportunities. For pop-up and permanent restaurants, the opportunity is clear, especially for restaurant chains that have specialised in refurbishing existing High Street buildings. That said, the impact of COVID-19 on the restaurant sector cannot be discounted, so it remains to be seen how the demand for new restaurants in city centres will play out. There is strong evidence to suggest that ‘stay at home’ workers are now looking for more local venues to eat out, instead of opting for city centre locations which typically would have been a popular destination for commuting workers. This has the potential for rapid development of restaurants in more suburban locales where available properties have typically been former pubs. Pubs themselves remain exempt from these planning changes, and should a restaurant utilise one of these new spaces then it will require permission from local authorities to operate takeaways or to sell alcohol from the premises. Other locations could adopt a multi-use model, shifting from business space in the day to restaurant in the evening, or operating a full time mixed-business usage within a larger building.

These changes are seen as a key opportunity to revitalise the High Street, but the one thing we know well at Adveco is the potential complexity, and therefore hidden cost, of refurbishing a property when the site was not originally conceived as a restaurant. Landlords and new property owners need to recognise that heating and especially hot water are business critical functions, with suitable hot water storage needed to meet consistent and peak-hour demands. That water also must be supplied at a minimum of 60°C to ensure a hygienic cleaning of the environment, utensils and provide handwashing for both staff and customers.

Adveco has 50 years of experience delivering commercial heating and hot water refurbishment projects. We will size the needs of the premises, design a bespoke application, and supply the necessary system components, and ensure it is commissioned for use and serviced to manufacturer’s quality as part of the warranty.  You can discover more about our recent work refurbishing systems in listed buildings and our work for Five Guys revitalising building hot water systems throughout the UK. In all these cases, our customers are not only securing modern, highly efficient fit-for-purpose heating and hot water systems, they are also reducing their costs and either better controlling their carbon emissions or excising them with renewables for a more sustainable workplace.

SSI 1500 Stainless Steel Indirect

Is a Calorifier Right for My Project?

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 temperature, 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.

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 low level to serve as an indirect calorifier in DHW installations. For more complex and renewable-based systems, the Stainless Steel Twin-Coil (SST) range offers 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.

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 their 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 become 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 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.

Discover more about Adveco water heating and how we can help size your DHW application.

 

Adveco packaged plant room.

Packaged Plant Rooms – A New Paradigm for Site Safety

Adveco discusses how off-site construction techniques for commercial heating and hot water can alleviate pressures of cost and timescale on construction sites whilst also helping improve Covid-19 safety precautions…

There is no doubt that we are going to face long term changes in the way construction projects operate during and in the wake of the current Covid-19 pandemic. Worksites are already having to adhere to stricter policy on where and when workers can traverse and engage on-site, and, in accordance with Government recommendations, the responsibility for their safety lies squarely on the shoulders of the host – not only for incumbent staff but also for any visiting contractors or customers. Ultimately this is all to ensure anyone on site does not become compromised. This means further stretching the usually difficult, and therefore costly, co-ordination of equipment and controls installations required for a building. Such complexity is typical, for instance, when creating and installing modern heating and hot water applications.

New world, new approach

Adopting offsite pre-fabrication as part of your project is therefore highly advantageous, reducing time on site required of specialist contractors, which is both more cost-effective and safer for all involved.

Adveco combines deep engineering understanding with a wide prod­uct offering and experience in full system design to provide a single source of supply for the delivery of complete packaged plant rooms containing heating and hot water systems tailored precisely to fit the specific needs of a project.

All work is carried out in a controlled, purpose-made environment. This means should there be any forced downtime on-site due to a local lockdown, the assembly work at Adveco will continue as planned. With no distractions from other typical construction site activities or issue we can ensure your plant room work is more rapidly progressed and, with a controlled factory environment, optimal manufacturing conditions are provided for quality control. Unlike the general conditions found on a construction site.

Locating all production work offsite also means the plant room element of a project can also efficiently progress at the same time as other groundworks or site installations. As the plant room arrives with all appliances, controls and ancillaries pre-fitted and connected – using stainless steel (heating) or copper (DHW) crimp pipework – as standard, there is no need for extended plumbing and electrical installation. This helps drastically reduce on-site labour demands and allows for more rapid progression of project timescales, despite social distancing requirements.

To achieve the best results, you will need to finalise facets of decision-making relating to hot water, heating or cogeneration of power early on in the project to allow for increased lead-in times. Once production commences it becomes more difficult to accommodate changes to a bespoke pre-fabricated system. This is why Adveco’s expert design engineers will work closely from the start with your project team to accurately size and design a system that meets the exact needs of the project on day of delivery.  All that is required is for flues, external pipework and final electrical connections to be completed on-site.

Adveco has broad experience of developing small to very large packaged plant rooms, embracing a wide range of cost-effective to operate and renewable technologies, from high-efficiency gas and electric boilers and water heaters to heat recovery units, micro CHP, solar thermal and Air Source Heat Pumps (ASHPs). These are all brought together to deliver a wide range of bespoke applications that can transform the operational nature of a commercial property, reducing emissions and improving the efficiency of hot water and heating for lower ongoing costs. The fact that these systems can also be delivered in a manner that is also much safer for all involved on-site shows the tremendous advantages to be gained from this approach.

Discover more about Adveco’s Packaged Plant Rooms

Bromsgrove Leisure Centre.

Sustainable Energy For The Leisure Industry – Part 2

In part 1 we discussed the importance of understanding how hot water, heating and power demands can be cost-effectively brought into balance, and why hybrid systems are key to achieving long-term sustainability…

As well as being able to be cost-effectively controlled, a hybrid system can also be optimised for CO₂ emissions by selecting the optimal (ecological) heat generator whenever possible via an energy management system incorporating smart metering. Should the building envelope subsequently be renovated, the required heating load will decrease further, and the existing gas boiler can take on less of the annual heating work and eventually could even be retired.

Depending on a building’s demand, we can also make a strong case for combined heat and power (CHP) where the CHP generates onsite electricity from a gas-powered engine, efficiently recovering heat from the process. Such an approach will still offer some carbon savings, definitely cost savings and, if that CHP is a low nitrogen oxides (NOₓ) micro appliance (m-CHP) when compared to the boiler, then we also have NOₓ saving. At worst, such a system is going to be carbon neutral but crucially low NOₓ which is increasingly a requirement for consultants and specifiers to pass building planning.

m-CHP also benefits from inclusion in the new SEG legislation so excess generated electricity can be sold to offset the CAPEX. The addition of m-CHP does require a certain level of oversight, so it is important to factor in the costs of regularly monitoring, managing and maintaining the system to ensure long term guaranteed efficiencies and relatively rapid ROI. As a result, compact micro-CHP systems have proven to be an extremely popular option across the leisure industry.

Adveco recently supplied Travelodge’s flagship 395-room London City hotel with a system that features an Adveco TOTEM T25 m-CHP unit. With continual background electrical power use and large domestic hot water (DHW) demand, Travelodge committed to a system based on micro-combined heat and power (m-CHP) which, when compared to conventional hot water solutions, attains substantial improvements in energy efficiency and reduced emissions.

Beautifully designed and fitted boiler room with mCHP, calorifiers etc.

The m-CHP pre-heats the system water via an MSS buffer vessel, which feeds six stainless steel calorifiers supported by a 572 kW A.O. Smith Upsilon boiler cascade. These plant components, all supplied by Adveco were installed into a rooftop plant room and commissioned by Adveco’s in-house team of engineers. m-CHP proved the most practical and cost-effective method for Travelodge to satisfy Part L of the Building Regulations, aiding its demand for sustainable and energy-efficient building design. And, with Totem’s NOₓ emissions at less than 10 mg/kWh, Travelodge is able to significantly reduce the building’s emissions of NOₓ, a potentially deadly polluting gas that is increasingly driving decision making for consultants dealing with projects located in highly urbanised areas.

Recently highlighted for its sustainability in industry awards, Adveco’s m-CHP application was also used by Bromsgrove Sport and Leisure Centre. Operated by Everyone Active, this was part of a large new build project designed to meet strict building and environmental standards. The new £10.3m facility providing a range of services to the local community including two swimming pools, sports hall and climbing wall, a 100-station gym, a fully-featured spa, and a café. With the pools and associated year-round heat demand, the leisure centre required a high-performance heating system.

To achieve the high level of energy efficiency to serve the building’s heating system required a 25kWe, 57kWTh TOTEM T25 -CHP appliance, as well as a bespoke 3000-litre buffer vessel, controls and ancillaries. Adveco additionally supplied two A.O. Smith BFC120 condensing water heaters to serve the domestic hot water supply to the leisure centre.

Since commissioning in early 2018, the TOTEM T25 at Bromsgrove Leisure Centre achieves 7,000 operational hours a year for an annual saving of as much as £10,000.  By producing both electricity and heat from the same supply of input fuel, the associated net reduction in carbon emissions has been more than 65,000 kg per year.

For leisure projects, high-efficiency condensing boilers and gas-powered m-CHP continue to offer considerable economic advantages in terms of operational costs for built assets. They also remain a realistic and effective means of meeting the demands for improved sustainability, which can be greatly enhanced by combining these technologies with other renewables. Whilst a gas/hybrid approach may be perceived as more conservative, it offers a route to a more sustainable future without removing potentially necessary and therefore valuable energy infrastructure which would be needed to support the introduction of green gas with its lower carbon footprint. Critically, a hybrid approach helps to plan for the future without being prohibitively costly.

Read more about the project at Bromsgrove Leisure Centre

Watch our video on the advantages of micro CHP for commercial buildings 

Bromsgrove Leisure Centre plant room.

Sustainable Energy For The Leisure Industry – Part 1

From hotel accommodation to restaurant kitchens, spas and swimming pools, leisure estates generate a wide range of electrical and heating demands. In terms of usage patterns, demands can be significant, often varied, but also constant, creating a complex range of challenging applications.

Currently, around 40% of UK greenhouse gas emissions are accounted for by heating, cooling, ventilation, the provision of hot water and lighting properties. The impetus then is to reduce operational energy use, prioritising reduction in energy demand and consumption over all other measures. This means in-use energy consumption will need to be calculated and publicly disclosed on an annual basis, as laid out in the new, mandatory Streamline Energy & Carbon Reporting (SECR) regime. This is designed to raise awareness of energy efficiency, reduce bills, and save carbon by driving an increase in renewable energy supply and prioritising on-site renewable energy sources.

From new builds to refurbishment projects, the leisure estate is faced with a myriad of choices, and, if medium or large organisations they are going to be increasingly held accountable by SECR for decisions that must ultimately balance both CAPEX and OPEX with this new sustainability.

A difficult task for an industry where heating and hot water are considered business-critical services and demands in terms of higher temperatures and usage far outstrip anything seen domestically.

The key then is to understand how hot water, heating and power demands can be cost-effectively brought into balance by maximising contribution to a building’s overall efficiency. Identifying technology concepts that help address such sustainability is only half the battle though, there still remains that need to reduce total cost of ownership. Space savings, ongoing supply reliability to simplified control and maintenance are all means to reduce costs and provide peace of mind when investing in a business-critical hot water and heating system.

Innovo commercial water heater by AO Smith

A.O.Smith’s Innovo Water Heater

Adveco's MD commercial condensing boiler

Adveco’s MD. A range of high-efficiency Floor-standing condensing boilers

Whilst arguments continue to rage regarding the validity of gas for a low carbon future, the reality is that for the foreseeable future our national infrastructure will continue to remain heavily reliant on the provision and improved use of gas. For leisure projects that face the most stringent legislation and oversight, high-efficiency condensing boilers, such as Adveco’s MD range, and room-sealed condensing water heaters, such as A.O. Smith’s BFC and Innovo units, remain a realistic and effective means of meeting the demands for improved sustainability.

When it comes to the refurbishing of existing building stock, which is where the greatest advances can be potentially made, installing solar thermal is going to be better from a renewables’ perspective. But we also recognise that this approach can be constrained by limitations of space, delivery timeframes and budget. ROI can also be much slower to achieve, despite the welcome new Smart Export Guarantee (SEG) legislation, under the which SMEs installing new solar photovoltaic panels, will from 2020, be able to profit from exporting excess generated electricity to the grid.

A smart approach would be to combine two heat generators, such as gas and solar, or gas and air source heat pump, although this can generate new issues of logistics, space requirements and increased complexity of plant, leading to a higher CAPEX cost compared to a pure condensing heating system. The advantages for a commercial leisure site from a hybrid heat pump/gas boiler system is the ability to smartly balance the heat generators, guaranteeing all-important high system temperatures while reducing the maximum power consumption for greater efficiencies and lower operational costs.

Corrosion in Commercial Heating and Hot water Systems – 1

Part 1 – Recognising the Causes of Corrosion

Most metals will deteriorate or corrode, sometimes to a more stable chemical state through oxidation or reduction. This occurs over time when metals are in direct contact with any water, rusted iron being the most familiar, but it can also affect copper, lead, aluminium, zinc, and numerous other common metals. This becomes a real issue in water heating and distribution systems where metal appliances and pipes are continuously being attacked to the point of physical failure.

Corrosion in Commercial Heating and Hot water Systems - Hard and soft water areas of the United Kingdom and IrelandCorrosion is a complex phenomenon, and no single dissolved substance is responsible for making water corrosive. There are several factors that can increase the likelihood of corrosion, especially the natural softness of water. When water passes through limestone and chalk in the ground, such as in the South East of the UK, it will pick up calcium and magnesium carbonates, when these minerals are greater than 280ppm the water is classed as hard. However, in Scotland, the North West and South West of England, and Western Wales, where water passes through hard igneous rock it lacks dissolved calcium and magnesium.  This makes the water naturally purer (less than 100 ppm). This soft water exhibits a low pH, low total dissolved solids (TDS) and negligible buffering capacity, all of which makes it more corrosive.

pH measures the hydrogen ion activity in a solution and is used to express the intensity of the acidity of a solution. Typically, the ideal pH for a hot water system is slightly above 7 on the pH scale. Water with a low pH (below 7) is acidic, which is a problem as acids are compounds that release hydrogen ions which oxidize metal, accelerating corrosion. In general, the lower the pH, the more aggressive the corrosion.

There can be a range of reasons for the formation of anodic and cathodic sites, required to produce corrosion. Different materials used in the manufacture of the appliance or pipework, localised stresses, impurities and variances in the production of the metal, its composition and ‘grain size’ can all lead to surface imperfections. If localised variances are relatively small the anodic and cathodic sites will move around on the surface of the metal leading to a more uniform corrosion which is typically seen as surface oxidation or fouling.

Should the anodic sites be more static, localised corrosion can occur. This form of corrosion – which includes pitting, leaching and galvanic corrosion – is a more serious problem which can more rapidly lead to the failure of an appliance or pipework.

Pitting, one of the most destructive types of corrosion, occurs when there are large differences in surface conditions, leading the anodic and cathodic sites to become stationary. The process is exacerbated by low-velocity conditions, leading to the creation of a pit on the surface of the metal, the water inside becomes isolated and, over time, more corrosive as it produces an excess of positively charged metal cations, which attract chloride anions. In addition, hydrolysis produces hydrogen (H+) ions. The subsequent increase in acidity becomes self-sustaining as the concentration within the pit promotes even higher corrosion rates.

Leaching is the selective corrosion of a single element from the alloy. The most common occurrence in a building’s hot water system is the removal of zinc from brass (a copper-zinc alloy), a process also known as dezincification. Though the copper and zinc dissolve out simultaneously, the copper will precipitate back from the solution. The resultant copper alloy will change from a yellow brass to red colour and exhibit poor mechanical property. Common in cheaper valves and fittings where there is likely to be other ‘filler’ metals in the copper alloy, water containing sulphur, carbon dioxide, and oxygen, low pH conditions, low velocity and high free chlorine radicals drive especially aggressive corrosion causing fittings or valves that move to fracture and leak.
The complexity of commercial hot water systems, especially if the project is a refurbishment, can lead to two dissimilar metals (such as copper and stainless steel) coming into contact with each other and water. Under these conditions the corrosion rate of the more active (anodic) metal increases and the corrosion rate of the nobler (cathodic) metal decreases. This is Galvanic corrosion.

The galvanic scale - Recognising corrosion in commercial heating and hot water systemsWhen differing metals are connected in a hot water system, the water in contact with both metals acts as an electrolyte conducting the current. The current flows through the water from the positively charged less noble material to the negatively charged more noble material. Where the current leaves the less noble metal, corrosion will occur. As the current is usually greater close to the contact point of the two metals, this is where corrosion will be a greater issue. The higher the metal is on the Galvanic series, the nobler the metal will be, whilst the greater the distance between the two differing metals in the series, the greater the electrical potential will be and the greater the corrosion rate for the less noble metal.

Another major cause of corrosion found in commercial hot water systems is a direct result of oversizing or the failure to correctly balance water flow. An unfortunately common occurrence, oversizing a system not only raises the capital expenditure and the running costs of a hot water system, but the oversizing of the pumps leads to high-velocity hot water to circulate through the system. If there are any suspended solids in the water, they will be driven against the metal leading to erosional corrosion which is typified by smoothly grooved or rounded holes which mirror the directional or turbulent flow of the water. This erosion is most notable at points where water changes direction or is obstructed, leading to turbulence which further increases velocity and therefore the damage. If the high-velocity flow is not addressed quickly it can result in considerable damage, especially to the circulating pipework.

Certain chemicals (such as chlorine, chloramine and dissolved oxygen) can also make water more corrosive. The presence of oxidizing agents such as dissolved oxygen can cause metals to lose electrons and lead to corrosion. The removal of sulphate, or addition of chloride, the Chloride-to-sulphate mass ratio (CSMR) will accelerate corrosion in the presence of materials that contain lead, leaching it into the water. Sulphates inhibit corrosion by forming passive protective film layers and reducing galvanic currents between dissimilar metals, chlorides prevent the formation of such passive layers and stimulate galvanic current. Should the source water contain natural levels of chloride and treatment be installed to remove sulphate, the expectation is this would push the CSMR up and as a result, accelerate corrosion. The base 60°C requirement for commercial hot water can worsen such cases as high temperatures accelerate almost all chemical reactions. As temperatures hit 70°C, which is not uncommon in commercial systems the rate of corrosion will increase.

Read Part 2 – Testing for corrosion