Working Towards A Cleaner Future

Adveco expert Bill Sinclair, Technical Director.Bill Sinclair, Technical Director, Adveco, considers the success of the UK’s drive to clean the grid, the role renewables can play and outlines the hurdles that still exist before we can mutually achieve a carbon-free future.

The UK was one of the first countries to recognise and act on the economic and security threats of climate change. The Climate Change Act, passed in 2008, committed the UK to reduce greenhouse gas emissions by at least 80% by 2050 when compared to 1990 levels, through a process of setting 5-year caps on greenhouse gas emissions termed ‘Carbon Budgets’. This approach has now been used as a model for action across the world and is mirrored by the United Nations’ Paris Agreement.

In November 2018, energy secretary Greg Clark triumphantly declared the energy trilemma to be over in a speech to Parliament which established a new set of principles to steer future development of the energy market. A market that can embrace the concept that cheap power is now green power.

The ‘energy trilemma’, so-called because of its summary of three key challenges that faced the sector, typically the need to decarbonise power generation in the cheapest possible way while guaranteeing security of supply, has been the core principle behind much of the government’s energy policy. “It is looking now possible, indeed likely, that by the mid-2020s green power will be the cheapest power. It can be zero subsidy. The trilemma is well and truly over,” declared Clark. Adding that, “Moving beyond subsidy does not mean to say we are reverting to the dirty, polluting world of the past, it is one where green energy can be cheap energy.”

However, there are still considerable challenges ahead if the government, UK businesses and those operating within the built environment are to ultimately meet the demands of the Climate Change Act.

A Cleaner Grid

Zero carbon energy sources are becoming more abundant and efficient, which is naturally having a positive impact on the grid’s carbon factor. As a result, carbon-intensive generation sources, like coal power stations, stay offline for longer, and this has led us to a pivot point in our reliance on carbon-intensive generation techniques. The carbon intensity, according to the National Grid, has “almost halved in a five year period.”

In January 2018 the carbon intensity of the grid ranged from 121 g/kWh to 443 g/kWh, a period where demand fluctuated from 23.78 GW to 49.11 GW. We can compare the winter range – around 300g/kWh – with the summer months, where load on the grid should reduce considerably without the heating demand. However, summer months carbon emission rates exceeded 200 g/kWh, and averaged out at approximately 175g/kWh, which is surprising because we would expect technologies such as photovoltaics (PV) to be performing at their optimal outputs.

In fact, the July centred heat wave created a higher carbon intensity than April or January.  We can presume this was due to higher electricity consumption by air-conditioning systems and possibly a fall in output from wind generation systems which would, in theory, be more effective in poor winter weather.

Increasing efficiency across the built environment

The tenth draft of the Government’s Standard Assessment Procedure (SAP) was released in July 2018 and has already had a significant impact on the way we view and use electricity with lower emissions that has cleaned up its image as a fuel compared to gas. Under SAP 10 emissions in electricity have dropped by more than 50%, a significant change that takes emissions down to 0.233kg CO₂/kWh. Gas emissions have also reduced by 2.8% within the same time frame, but gas is going to be relatively constant when it comes to emissions because it is not generated, but rather is effectively mined. This means the end-product does not get any cleaner, the reduction is a product of improved pumping process and less distribution loss. Before this substantial change, electricity was considered 2.4 times dirtier than gas, today that ratio has dropped to almost one to one.

These developments are obviously having a considerable impact on the mindset towards electricity as an energy source for heating and hot water to serve the built environment. For a starter, new commercial builds with a small requirement for domestic hot water (DHW) load will benefit in a big way from installing any heat pump technology.

But for new builds exhibiting a large DHW load then there remains a solid argument for employing a gas-fired water heater. However, the smart approach is to also use a heat pump to create a hybrid system to pre-heat the DHW system. This gives a project considerable carbon advantage from the heat pump, because the COP is higher when the output temp is 50 instead of 65, and very high when the ambient is warm. In addition, running costs are kept low by only heating water at the cost of gas, be it from the gas or from electric with a minimum 3.5:1 COP.  This type of hybrid system approach also reduces the maximum available electric load the building needs, allowing for an incredibly carbon-efficient hot water system, and in warmer weather reduces a building’s dependency on gas to nearly nothing. There are also benefits to be had from reducing grid demand at peak times, and then utilising the heat pump at its most efficient.

In theory, the RHI for air-to-water heat pumps should also be re-evaluated. Previously the minimum efficiency to be eligible was a SCOP of 2.4, as this was the boundary where gas was a more carbon effective energy source. Not to encourage carbon intensive buildings, but that boundary could be lowered and still have a positive carbon impact on the existing building stock. And if a heat pump with a lower efficiency was selected, capital outlay would, in theory, reduce as well.

So far so good, but how successfully is this delivering against the need to reduce greenhouse gas emissions as set out by the Climate Change Act?

Halfway there?

The encouraging news is that greenhouse gas emissions have already been reduced by approximately 42%, so we are just over halfway to the end goal, but the problem is the first 50% is the easy bit – increasing renewable energy sources and limiting coal fire stations – but what do we do to continue?

It is expected that 2018’s emissions in the final reckoning will be of a magnitude of 468 megatonnes of CO₂ equivalent (CO₂ E). Shorthand for a collection of greenhouse gases, CO₂ E includes carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride. Carbon dioxide is the main target, making up 81% of all greenhouse gasses in 2016, and for this reason it’s the element that we think of reducing when targeting for a greener future.

The Government’s Carbon Budgets have so far been achieved through a mix of incentives, such as the Renewable Heat Incentive and Feed-in Tariff, and regulation (Building Regulations Part L). In this way the UK has been able to meet the requirements of Carbon Budget one and two, as well as achieving the third budget’s requirements (37%) well before the 2022 deadline. Despite Clark’s recent positive comments, the Committee on Climate Change estimates that we are not on target to meet Carbon Budget four, requiring a 51% decrease, by 2028.

The government stated in its 2017 Clean Growth Strategy “In order to meet the fourth and fifth carbon budgets (covering the periods 2023-2027 and 2028-2032) we will need to drive a significant acceleration in the pace of decarbonisation.”

Where we can start to make a real difference

The National Grid has already begun to outline potential future energy scenarios, but it is down to our industry to assess how low carbon technologies can be deployed in a meaningful way to address these scenarios. This means considering the effect of lower carbon intensity electricity on renewable technologies with emphasis on existing, as opposed to new builds.

From the systems already outlined it is clear there remains a strong argument for employing gas alongside renewables in new builds. When it comes to the refurbishing of existing building stock, that is where the greatest advances can be potentially made across the built environment. In such a scenario though, it is never going to be worthwhile for the building owner to put in a heat pump for preheat or as a standalone hot water source. From a renewables perspective it is going to be better to put in solar thermal. But when an existing building needs to be improved then it cannot be cost-prohibitive for the owner. This means it needs governmental support which generally makes solar thermal cost-optimal if the project site has the capability to support an installation.

As with all refurbishments, the physical limitations of a site will always drive or preclude certain options. Without doubt, gas infrastructure remains the most common for the provision of heating and DHW and a more open-minded approach to driving cleaner heat through a mix of replacement gas and renewables is what will really progress us towards the 2028 targets while also delivering considerable benefits to those living and working in these buildings.

Balancing Sustainability and Commercial Heating Demands

Adveco’s Adveco expert Bill Sinclair, Technical DirectorTechnical Director, Bill Sinclair,  considers the latest developments in commercial condensing MD boiler technology…

Faced with balancing the business-critical need for space heating against stricter legislation and the demand for greater clarity of what they are doing to reduce emissions, how can UK commercial organisations better address the heating demands of their large buildings?

With the majority of national infrastructure currently ‘on gas’ and delivering half of UK’s non-transport primary energy needs, gas-fired boilers remain the best option for the provision of heating. The increasingly stringent government legislation that industrial and commercial establishments face in terms of reduction of carbon emissions and hazardous air pollutants is 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. In such a scenario, the continuous low-grade heat from the heat pump works alongside the fast responsiveness of the gas boiler which is used to top up heating and avoid the requirement for higher carbon-emitting generators at electricity peak demand times.

Requiring less fuel, due to recovery of latent heat from vaporisation, high efficiency condensing boilers can lower running costs and provide higher temperatures than a heat pump. Offering reliable operation, simple controls and compact design we are seeing increasing interest in adopting hybrid technology as a practical response to the consistent need for commercial heating and the wider requirement to be compliant with latest legislation.

Reducing the cost of business-critical heating

As an independent provider of heating systems, identifying technology concepts that will address sustainability is only the start. We also recognise the need to meet customer requirements for cost of ownership, which can be met through several features, from space savings, ongoing supply reliability to simplified control and maintenance that provide peace of mind when investing in a business-critical heating system. From restaurants and hotels, to leisure facilities, schools and university accommodation the needs are increasingly universal for large application, very efficient and low emission heating.

Whether limited by existing structures in a refurbishment, or reducing cost in a new build, saving space is an important consideration. But when a system demands more than 300 kW output there has been little option other than to build a costly frame and implement a design incorporating the necessary wall-hung boilers in cascade until the system’s needs are met. By which point you effectively have a floor standing system that negates the space advantages of a wall-hung boiler. For this reason, some will consider a floor standing alternative, they are after all relatively low cost and can supply high loads. The problem is that such appliances offer a single fan, gas valve and heat exchanger which means there is no system redundancy. That makes for false economy when it comes to delivering a space-saving, consistent 24/7/365 heating system.

We would advocate a modular cascade concept that takes full advantage of the compact size afforded by condensing natural gas or LPG boiler technology, with low water content heat engines, built-in redundancy and no need for an expensive framework to convert wall-hung boilers to floor standing.

Adveco’s MD, 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 and assuring clearance for maintenance. The need for, and cost of a frame is immediately negated, and issues of limited headroom are quickly resolved. A high maximum run pressure, up to 11 bar, makes it highly suitable for large, high-pressure applications.

We can also demonstrate a turn down as low as 14 kW and 94% redundancy in case of failure. Of course, while built-in redundancy is advantageous, the supply reliability should not hinge on redundancy systems but features that are designed to prolong the life of the appliance.

Typically, new condensing boilers will be fitted with a heat exchanger made from non-ferrous metal, usually stainless steel, to counter corrosion. Adveco’s MD incorporates unique and extremely high-quality AISI 316Ti heat exchangers constructed from a continuous, non-welded run of titanium-stabilised stainless steel. This approach reduces weak points and offers improved strength and corrosion resistance at high temperatures for long periods of time, reducing the chance of failure while ensuring high capacity heat transfer.

The patented design features a large bore, three-pass arrangement with circular, not flattened, cross-section tubes to reduce the collection of debris. To maximise condensation means operating at a sufficiently low temperature, and this requires condensing boilers to be tolerant of the condensate. The inclusion of a refillable limestone bed is truly advantageous, neutralising acid condensate which can dramatically affect the lifespan of an appliance.

Each heat exchanger also incorporates a control board that allows communication and load balancing across adjacent exchangers, meaning that the system not only provides built-in redundancy, but also offers improved reliability and longevity as all internal components receive uniform wear. This integrated system control not only provides an intelligent maintenance self-check of all primary appliance components and functions, but also incorporates MODBUS communication and alarm output to assist with BMS integration.

As a result, condensing boilers can meet the demand for reliability and efficiency for lower cost of ownership. We go as far as to offer an industry-leading 10-year warranty on the MD’s heat exchangers and burners, with a seven-year parts and labour warranty for long-term peace of mind.

Meeting Commercial Sustainability Goals

We can easily demonstrate the functionality and the cost savings of adopting a modular cascade concept with high efficiency condensing gas boilers, but what of the air quality and sustainability of the technology?

To improve combustion efficiency, condensing 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. In the case of the MD, a high-efficiency pre-mix burner achieves ideal combustion efficiency of up to 107% (net)/98% (gross) reducing energy costs and producing low emissions. With low CO and NOX emissions, a heating system built around a high efficiency condensing boiler (Class 6 appliance) satisfies the requirements of the Energy-related Products (ErP) directive.

Correctly sized and professionally commissioned, a cascade system with high-efficiency pre-mix burner 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 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 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.

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 – from hybrid systems to the introduction of green gas with its lower carbon footprint. 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 sustainability, while offering considerable economic advantages in terms of operational costs for built assets.

Commercial Air Source Heat Pumps (ASHP).

Adveco Introduces the FPi Range of Commercial Air Source Heat Pumps for Hybrid DHW Systems

  • Delivers above average coefficient of performance to help reduce a building’s energy consumption and reduce operational costs.
  • Perfect for hybrid DHW systems that help meet new carbon targets.
  • Quick and easy to install and then maintain.

Hot water and heating specialist Adveco, in partnership with Italian heating manufacturer Cosmogas, introduces the FPi range of commercial-grade Air Source Heat Pumps (ASHP). The two variants, the FPi-9 and FPi-13, provide excellent levels of performance, especially throughout the UK’s relatively mild winters.

FPi delivers an easy to install method for commercial sites to achieve lower cost water heating or cooling. With sleek looks and quiet operation, the compact monobloc design is capable of providing domestic hot water (DHW) at up to 55°C, or cool water to -7°C for use in fan coils.

Bill Sinclair, technical director, Adveco, says:

“The FPi range of ASHPs is perfect for combining with a traditional gas water heater and controls to create a hybrid system. Offering better compatibility with existing DHW distribution systems and the demands of higher thermal requirements. This approach provides the versatility to reduce operational costs while maintaining the higher water temperatures demanded by commercial DHW operations. A hybrid system built around the FPi can help businesses meet their carbon targets in the coming decade, while keeping running costs low.”

Due to advanced vector control technology that provides an accurate response to variable operational cycles throughout the year, the FPi range is able to achieve an above-average coefficient of performance (COP). Ranging up to a very high COP of 4.7, FPi ASHPs can make a real impact on a property’s energy consumption.

The FPi range is virtually maintenance-free, requiring simple, regular cleaning of the coil and filter. Sensors constantly check pressure and each unit is equipped as standard with frost protection, enabling them to operate effectively with excellent yields even if temperatures drop as low as -25°C.

Technical Information

 

  FPi-9 FPi-13
Dimensions HxWxD (mm)

 

753x943x354 1195x1123x400
Weight (kg) 62.5 113
Noise level (dB(A)) 56 59
Max. heating capacity (1) (kW) 10.1 12.6
Max. heating capacity (2) (kW) 9.53 11.5
COP min. / max. (1) 4.02/4.65 3.89/4.7
COP min. / max. (2) 3.12/3.55 2.97/3.28
Circuit max. pressure (bar) 42 42
Rated water flow (L/s) 0.43 0.61

 

(1) Heating condition: Water in/out temperature 30°C/35°C. Ambient temperature DB/WB 7/6°C.

(2) Heating condition: Water in/out temperature 40°C/45°C. Ambient temperature DB/WB 7/6°C.

Adveco Showcases New Hybrid Packaged Plant Rooms at CIBSE Build2Perform

  • Accelerate project timescales with offsite constructed heating, hot water and low carbon energy systems
  • Introducing packaged hybrid systems that help meet new carbon targets
  • Understand whether continued investment in gas infrastructure is still viable

Hot water and heating specialist Adveco, will be exhibiting its first hybrid packaged plant room systems for heating and hot water at CIBSE Build2Perform November 26th & 27th at Olympia, London. These bespoke designed systems, built into a weatherproof enclosure, not only maximise available space on a commercial project but also deliver system resilience, help reduce a building’s energy consumption and reduce operational costs.

Adveco’s plant rooms leverage technology from a range of partners including A.O. Smith, Cosmogas and cogeneration specialist TOTEM. Appliances are combined with Adveco’s own in-house designed control systems and industry recognised heat recovery technology, such as the HR001, a standalone Heat Recovery Unit providing a convenient, packaged unit to recover refrigerant system waste heat.

For the first time, Adveco will be showcasing a hybrid application that combines the new Adveco FPi Air Source Heat Pump with an A.O. Smith Innovo condensing room-sealed gas water heater and controls, enabling commercial sites to achieve lower cost heating or cooling.

An all-electric packaged plant room will also be on display alongside the popular MD high efficiency condensing gas boiler.

MD high efficiency condensing gas boiler - floor standing or wall mounted.Compact and lightweight, with low CO and NOₓ emission levels, MD is perfect for use in conjunction with an air source heat pump as part of a hybrid system, providing both sustainability and the operational responsiveness required by larger-scale commercial systems. With multiple load-balanced heat exchangers in a single chassis, MD offers peace of mind with built-in redundancy, all backed by a seven-year warranty on all parts and labour when commissioned by Adveco and a 10-year warranty on both the heat exchangers and the pre-mix burner.

Adveco’s Application Engineer Simon Bennet.On Wednesday afternoon, Adveco’s Application Engineer Simon Bennet will be helping designers facing the decision of whether to adopt all-electric for new buildings or outlay for a gas supply ready for conversion to hydrogen. A decision that could affect future carbon emissions and running costs for the lifetime of the building. Simon will outline the practical considerations to help decide whether the cost and the need to reduce carbon make continued investment in gas infrastructure viable for commercial new build projects.