One of the main topics at last week’s CIBSE Building Performance Conference and Exhibition, indoor air quality is fast being recognised as a priority concern in the world of wellbeing. But in a field where marginal gains are everything, being on top of your data is very important Arie Taal from the Department of Mechanical Engineering at The Hague University has produced research into eliminating faults in HVAC using a BMS

Carbon Dioxide based demand control ventilation (DCV) can reduce heating/cooling loads by up to 30% and fan power consumption by up to 35%.  DCV maintains the CO2 concentration in a room within an appropriate range by adjusting the supply air flowrate.  CO2-based DCV is the most commonly used control method with CO2 sensors installed in the main return air duct.  Nowadays, the increased requirement for smart buildings, combined with a decrease of CO2 sensor prices, has resulted in buildings being equipped with more sensors.

A common issue occurs when one of the CO2 sensors encounters a fault.  This can be down to a lack of maintenance or incorrect sensor placements in rooms.  In a DCV system, a fault can mean that the estimated energy savings and air quality is not guaranteed.  In 1993 the Automatic Background Calibration (ABC) method was developed to calibrate CO2 sensors with the idea that CO2 levels would drop outside normal levels in buildings that are not occupied on weekends or weekday evenings. However, placement of sensors can become a problem as rooms on the inner side of a building or rooms with well-sealed windows may never drop outside of these baseline levels.
Alongside Dr Yang Zhao and Prof Wim Zeiler at the Department of the Built Environment, Eindhoven University in the Netherlands, Mr Taal has been working toward a systematic method of diagnosing faults in CO2 sensors.  Using automatic fault detection, diagnosis and self-correction in CO2 sensors would be a proactive method in air conditioning systems to solve this problem.  The premise of Mr Taal’s study has been to show how the automatic commissioning of CO2 sensors in air conditioning systems is achievable using benchmark values obtained in one of two methods.

In conventional methods, sensor faults are detected by comparing their measurements with benchmark values.  These values can be obtained manually, measured by technicians, or calculated automatically using other available measurements.  The latter is more common because it can be done automatically in the building management system (BMS).  Practical issues arise in air conditioning systems because there are no sensors equipped to measure the CO2 generation rate, CO2 concentration in the supply air and the flow rate of the supply air in m3/s.  In the development of models for CO2 sensor fault detection, the lack of information poses a real challenge.

In an effort to eliminate the threat posed by this lack of information the idea is to perform one of two test methods under specific operating conditions to ascertain the required benchmark levels.

The first is to recycle air without adding any outdoor air for between one and two hours to create 100% return air ventilation.  By closing all windows, doors and fresh air dampers in air handling units the measurements of all CO2 sensors should theoretically be the same.  The second test is full outdoor ventilation, to supply fresh air into the building without any recycling for between one and two hours.  Again, at the end of the time period all of the CO2 sensors should be the same and equal the CO2 concentration of the ambient air.

Faulty sensors will be detected if their readings are different from the assessed benchmark values.  A faulty sensor can be detected if its measurements are obviously higher or lower than other sensors.

In the first method, the degree of fault is then measured from the difference between the defective sensor and the average measurement of the other faultless CO2 sensors. The second compares the faulty sensor reading to the ambient CO2 concentration both looking for a negative or positive bias in CO2 levels when measured against the benchmark.

Self-correction is the final step in the process where all of the information is taken from the faulty sensor for adjustment.  Using the assessment results from the fault diagnosis the CO2 bias can be corrected.  The results of the detection, diagnosis and self-correction will then be reported to technicians for reference.

Together with his team, Mr Taal produced a simulation of their works on the first floor of a school building at The Hague University in Delft.  In their experiment, nine rooms were used with a CO2-based DCV applied to control the amount of supply air to each room in order to keep the CO2 measurements within the benchmark.  Separate experiments were conducted to simulate different conditions. The first simulates a fault free operation and a second introduces faulty sensors to show the impacts of automatic fault detection system.

Using two operating methods to obtain CO2 benchmarks, 100% return air ventilation and full outdoor air ventilation; faulty sensors can be detected, diagnosed and self-corrected using a BMS.  From the simulations, results show that after 45 minutes there are obvious differences between functional sensors and those that are faulty.  After an hour and a half the positive or negative bias can be accurately measured.

Theoretically, the proposed methods are effective ways to detect faulty CO2 sensors, effectively diagnoses the state of failure and to automatically remove the fault.  The ability to automatically detect, diagnose and repair faults is vital to the effective running of DCV systems.

The performance gap is the big problem of our times in the building services industry, and hundreds of column inches are devoted to products created to fix it each year. Ahead of his presentation at the CIBSE Conference Casey Cole, Managing Director of Guru Systems, presents an alternative view: That process, not technology, is the answer  

New buildings in the UK consume far more energy than predicted by their designers – up to 10 times more according to an Innovate UK study. This performance gap doesn’t arise because we lack technology. Studies by the UKGBC and others conclude that it’s the result of failings throughout the project life-cycle, from concept to handover.

Performance gaps may arise because clients are unclear about what they want; project teams don’t understand the impact of their design choices; contractors substitute products and materials on the fly and then install them poorly; or quality assurance is lax, with employers’ agents either blind to the problems or willing to let shoddy work escape their net.

There’s no doubt about it – we’ve got trouble right here in the UK building industry. But innovation on its own won’t solve the problem. The Internet of Things isn’t coming to the rescue. Because the performance gap isn’t a technology problem – it’s a problem of people, information and accountability.

That’s a sobering realisation, because we’ve all drunk the same Silicon-Valley-brand of neoliberal Kool-Aid. We know that given the right market signals, some whizzy new technology that no one has yet thought of will appear and address any problem you can name: from climate change to… well, to the performance gap.

But not this time. Any purely technological solution would simply be papering over the cracks in our poorly functioning buildings, cracks that were put there by project teams.

There’s a positive side to our realisation: if we don’t need new technologies to close the performance gap, then we already have the tech we need. Indeed, I think we do. But, that technology must be used to empower clients, engineers and all of us on the project team to do our jobs better. Here’s how:

The first step is to collect data from existing buildings. Organisations like CBx, Digital Catapult and Guru Systems, the company where I work, are already doing this. This data is being collected from utility meters (e.g. smart meters and heat meters), building energy management systems and other monitoring systems. By analysing this data, we can understand which factors have the biggest influence on performance.

We can then set clear performance requirements and explicit means of measuring them. These must be measurable before the building reaches practical completion, while the people who can put it right are still on site. It’s no use specifying kWh/m2/annum or any other target that can only be calculated once the building is occupied. By the time they can be measured, the project team will have long since moved on. So, we must define requirements for the characteristics that are measurable before occupation and that lead to good performance in operation.

Most importantly, clients must make performance requirements contractual. Those clear, measurable objectives must be written into the invitation to tender and then into contract. The lead contractor and the rest of the delivery team must know from the outset what’s expected of them (and that they’ll be held accountable for achieving it). We have a number of clients that have now adopted this approach for heat networks and they’ve shown that, once it’s contractual, everyone’s incentives align and the gap between expectation and outcome closes.

Casey Cole is speaking on ‘Are you ready for a digital future?’ at the CIBSE Building Performance Conference on Thursday, November 17 from 10:25am to 11:20am.

In this week’s #Build2Perform blog, we’re getting a bonus word from CIBSE President John Field. As well as his regular Presidential blog, he’s written for us about his thoughts ahead of the 3rd Building Performance Conference and Exhibition on 17th and 18th November – how it’s relevant, how it ties into the future of building services, and why it’s exciting!

As CIBSE President one of the biggest and most exciting honours that we get in the job is to preside over a CIBSE Conference. Now in its third year, the Conference is an opportunity to mingle with and hear from some of the biggest names in our industry and grapple with the big issues of the next few years. This year I’m also chairing the second day, in which we’ll be looking at some of the major organisational challenges within the industry such as collaboration and new technology.

The most interesting thing about the Conference is that, while it obviously has a big industry focus, we’re also directly engaging with some of the most significant challenges that the whole world faces over the next hundred years. Climate change, overpopulation, energy security, health and quality of life are all well within our remit, and it’s at events like this that you can truly see how important a position building services engineers occupy in society. We make the modern world work, and this is where we look at how to make it better.

Our key theme this year is ‘Inspiration’, which is hard to pin down but crucial to the future of the way we work. Given all I’ve said about engineers’ place in the world, we still don’t occupy as central a place as we ought to in positions of power – contributing to planning and policy making in the many areas to which we contribute. Unlike lawyers and bankers, engineers don’t have much representation in the UK Government. Our voices often go unheard and our advice unheeded, and we need to change that. We need to fight for influence and be prepared to challenge other engineers, other professions, politicians and the media in order to make sure sustainable and sensible policies in the built environment are top of the agenda.

With that in mind, we’ll be looking into both the past and the future on our first day. Celebrating anniversaries at their own companies and in the 40th year since the creation of CIBSE in its current form, Patrick Bellew of Atelier Ten and Max Fordham will be looking back at how the traditional role of the building services engineer has changed in the last 50 years. Then we’ll be looking forwards – why have warnings about building performance been ignored by Governments past, what can we do to change that, and what is coming up in the legislation pipeline that will affect our industry in future?

We’re also getting to the bottom of a couple of burning issues in the industry. Air quality will be the subject of a number of talks, ranging from external air quality’s effect on the indoor environment to the ways in which indoor air quality can be improved in homes and schools. We’ll also be re-visiting the theme of collaboration from last year’s Conference, looking at what we’ve learned since then and examining the role that individual sectors have to play in the industry as a whole – from the supply chain to facilities managers.

As well as looking at the nuts and bolts of building performance, the Conference is a great chance to debate the big ideas as well. Talking about grander themes and longer-term ambitions is a great way to focus our minds on the potential of our industry, and the differences we can make to the world. We’ll be taking a look at the perfect world: What society would look like if all buildings achieved their best engineering outcomes. We’ll be looking at the imperfect world: What are the true health impacts of air pollution? And we’ll be looking at a better world: How can we ‘turn old into gold’ and make the most of the UK’s current building stock through retrofit.

It is this combination of the practical and the aspirational that makes the Conference so exciting, and the interaction of the two is at the heart of what is going to drive our industry forwards. We know that our industry represents some of the most knowledgeable technical experts in the world, and that we can do amazing things when we bring this knowledge to bear. We aim to create an environment where we can marry the two, and use our skill to make our vision happen. With a gallery of top experts here to speak, as well as over 500 people from across the industry, the Queen Elizabeth II Conference Centre is going to be an inspiring place for those two days in November, and we hope to see you there!

The CIBSE Building Performance Conference and Exhibition will be held on 17th and 18th November at the Queen Elizabeth Conference Centre in Westminster. For more info see the CIBSE Conference website.

At the upcoming CIBSE Building Performance Conference and Exhibition, we’re going to be focussing heavily on the future of the industry – particularly the ways that new technology can be brought to bear on performance in the built environment; to find easier, smarter and cheaper ways to make buildings perform to their potential in a variety of different ways.
This week, we’re speaking to two industry experts: Mat Colmer, Built Environment Specialist at the Digital Catapult Centre, and Nick Winser CBE, Chairman of the Energy Systems Catapult, who are giving is their views on technology in the built environment: What’s hot, what’s not and where the biggest changes are going to come.

What are the innovations in technology that will make the biggest impact to the performance of buildings in the next 15 years?

N W: I’m not sure there’s going to be a stand-out technology innovation, and fifteen years is actually not that long to make a big impact. A new home energy gateway that learns about the thermal performance of our buildings and the requirements of the occupants could provide a platform for all sorts of innovative energy services, with the potential to start a transformation in consumer and market engagement.

M C: Wireless sensor networks and IoT will have a big impact in the near term. Having reliable hyper-local networks that are off-the-shelf and interoperable will bring down the costs of monitoring our buildings, particularly monitoring the efficiency of services, and allow for products that encourage user feedback. This will allow us to gather far more information on what happens with buildings in-use.

What are the innovations in buildings that will make the biggest environmental impact in the next 15 years?

M C: Advances in curtailing energy use through intelligent metering and management, demand response and the wider use of DC power transmission will have a significant impact. Increased use of DC power additionally makes the prospect of decentralised power generation more attractive and can increase energy security.

N W: Energy efficiency itself isn’t a great driver of consumer action – for most people, spending money just to save kilowatt hours is not that attractive, and it’s unlikely to compete with other household demands. So whilst we must improve the effectiveness of efficiency measures, and reduce the cost, this needs to be coupled with imaginative new business models that refurbish living spaces, provide greater comfort, and as part of this deliver the required efficiency improvements.

If you could only recommend one change in process or method to improve building performance, what would it be?

N W: I think there’s a real need for focus, not just on the requirements of individual buildings, but for whole areas of our cities, towns and communities. Someone, and maybe it’s the local authority, should have the responsibility and design tools to develop local energy strategies that take account of house types, geography, supply networks and the availability of energy resources like waste heat. Growing consensus like this will be a massively important step to help individual occupants make the right future-proof decisions and find suppliers to deliver them.

M C: Make time to learn from the experience of others. Too often the same mistakes are made purely because time and budget constraints discourage creativity and encourage the familiar.

What is the most exciting potential collaboration opportunity in building services over the next 15 years?

M C: Advances in virtual reality and augmented reality technology will enable visual and interactive collaboration across sectors. Many problems in construction projects originate from poor communication. VR and AR technology allows partners to use shared spaces to explain and revise designs. Consequently misunderstandings and errors are less likely to occur.

N W: I think there’s a great opportunity for energy to be much more than a utility purchase. I’m sure we will see retail players who have trusted brands, using their reputations to develop new products that include home refurbishment with energy efficiency built in, and maybe other organisations that can bring a ‘lean’ process mindset to help advance the retrofitting of the nation’s buildings.

Welcome to the fourth #Build2Perform podcast! This month, we’re concentrating on the issue of indoor air quality. What is it, why is it important and what can engineers do about it? I’ll be speaking to two experts in air quality, independent sustainability consultant Julie Godefroy and Alan Fogarty of Cundall, to answer those questions and more!

You can listen to the podcast below, but you can also find it in the iTunes library and on other podcast apps by searching #Build2Perform if you’d like to listen on the move via smartphone or tablet. We’ll also be discussing the podcast on Twitter under the #Build2Perform, and you’ll find useful links about what you hear under the podcast below.Indoor air quality is becoming one of the next great public health issues of our time, and is being considered more and more by designers as a fundamental part of the building’s health. Overshadowed somewhat in the public eye by its outdoor cousin, more and more research is being carried out into an area that could claim more than 40,000 lives a year in the UK alone.One of the most recent and comprehensive studies carried out int his area is by the Royal College of Physicians, and takes in both indoor and outdoor data. CIBSE also has knowledge available specifically on the indoor component, such as KS17: Indoor Air Quality & Ventilation, published in 2011.

From a regulatory perspective, both the UK Government and the European Union have rules on indoor air quality standards, which are summed up by the Government here. Indoor air quality in the home and in schools is a major thread at this year’s CIBSE Conference and Exhibition. Sessions that deal directly with this issue are:

Performance, Inspiration and Aspiration are the keywords behind the 2016 Building Performance Conference and Exhibition, organised by the Chartered Institution of Building Services Engineers (CIBSE) as it officially launches this year’s programme.

Following on from CIBSE President John Field’s promise to inspire engineers to ‘talk the talk’ and fight for their place at the heart of modern life, this Conference will bring together over 40 expert speakers to showcase the latest thought on building performance and help engineers deliver and maintain high performing buildings.

The Conference, due to be held on 17 and 18 November at the QEII Centre in Westminster, is a chance for engaged industry professionals from the built environment  sector to meet, learn and debate the critical issues facing the industry, from health and wellbeing issues to maintenance and operational performance. It is already proving to be a popular event, having attracted the highest number of pre-registrations to date.

A series of leading speakers will tackle these issues, offering employable solutions in their addresses; including Outlook for Building Performance, Digital Engineering & Building Services, Achieving Performance In Use, Air Quality: Impact on Health & Wellbeing. Collaboration for Better Performance, Refurb + Retrofit, and Innovation in Buildings.

John Field, President of CIBSE and Chair of day two, said: “Engineers are at the centre of everyday life, we make the modern world work in obvious and not-so-obvious ways, and it’s in our power to help make the world a better place in many areas, from tackling climate change to improving how people live.

“The CIBSE Conference is an ideal time to get together and be inspired by what we have achieved, and what we can achieve in the future. Using what we learn in these sessions, we can take big ideas to business, the media and politicians and help shape the future of the UK, and make it a beacon for excellence in building performance for years to come.”

In the Conference programme, sessions include: ‘Are you ready for a digital future?’, ‘Build to Perform: Realising the commercial drivers and opportunities in high performing buildings, what the world could look like if all buildings achieved best engineering outcomes, Facilitating collaboration for optimum performance from teams and buildings, and High rise buildings on the up: What do the building services look like?

The Chartered Institution of Building Services Engineers is hosting the Building Performance Conference and Exhibition at the prestigious QEII Conference Centre in Westminster on 17-18 November 2016. Attendees will be able to meet and network with over 300 like-minded professionals, clients and suppliers from around the world.


The CIBSE Conference and Exhibition will inform and inspire building services professionals including consultants, designers, facilities managers and engineers, and offer up to 10 hours of CIBSE CPD.

On the first day of the conference 17 November 2016, we are delighted to have a very special interview between Patrick Bellew (left image) and Max Fordham (right image) on their visions of our future built environment, start the conference.


Two of the most influential and well-known building services companies are celebrating significant anniversaries. Atelier Ten celebrated their 25th anniversary in 2015 and in 2016 Max Fordham LLP will be 50 years old.

The practices are led by iconic figures in building services engineering. Patrick Bellew, Atelier Ten, and Max Fordham at his eponymous company. These two giants of the industry will be interviewed together at the CIBSE Building Performance Conference 2016. Two of the industry’s most influential environmental engineers will share their visions and aspirations for the next 50 years in building services.


Bored with BIM? For all the potential that the technology holds, it’s something that industry professionals are finding hard to get excited about. CIBSE BIM Consultant Carl Collins writes for us this week about how we can fall back in love with data. Be honest: How many people do you know that are actually excited about BIM these days? It is trumpeted every day in trade media as the solution to just about everything in its many forms, and the possibilities are undeniably exciting. So why is it that, on your average project, the BIM aspect is about as inspiring as doing your tax return? It has an image of rules and regulations, compliance and guidelines. An annoying box to be ticked.

Somewhere along the line BIM got institutionalised – it ditched the jeans and t-shirt and put on a grey suit. It stopped being inspiring and became just another tool in the box for meeting project requirements, and staying the right side of the law. But it wasn’t always this way.

It might be a relatively new phrase, but we’ve been digital engineers for a long time. When I started in mechanical engineering, I was a draughtsman – the big desks and long rulers that are almost museum pieces today were commonplace, and computers were few and far between. It was the sort of thing you invited visitors to your office to come and look at, like a new baby or a car.

Ok, maybe not QUITE that long…

Back then, we were using simple CAD applications on computers that were little more than virtual drawing boards – these were the ancestors of the modern 3D BIM models we know today, but far more important was what else we were doing. For the first time we were using computers to interpret and store information for us, to help eliminate errors and to automate certain processes. That’s when BIM truly started, and when the digital engineer was born.

And that’s the really exciting part of BIM that I want us to re-capture – the massive iceberg under the surface that represents the most valuable part of BIM: The way we capture, organise and deploy data. It’s not just an expensive add-on to a project, it’s more like a way of working that permeates everything we do. Part of what I’ll be doing at CIBSE is training people to think differently about BIM in order to use it better by using it more creatively.

The best thing about BIM is its freedom, rather than its constraints. At the end of the day it’s just data, and it’s how that data is organised that determines what it does – so it’s really up to you to use your imagination, and apply the technology in novel ways to solve a problem. If that sounds simple, it’s because it is. Fundamentally, it’s no different to what engineers have always done: solving problems by doing creative things with the tools available. So we’re all digital engineers, but we need to embrace this role to make the most of its potential.

Engineers have always solved problems with innovation, like Atelier Ten’s 2014 Building Performance Award winning ‘Gardens by the Bay’

But why is this relevant now? We’ve been using BIM for years, and using computers in this way for decades – but the more recent rise of ‘smart’ technology which embeds sensors in just about everything is revolutionising the types and quality of data that we can collect. At the recent IFS Digital Britain event, the Chairman of the HM Gov Construction BIM Task Group Mark Bew gave the NHS as an example: If we can make people healthier by making the buildings they use better, we can save the NHS billions every year just in money they’ve not had to spend. Similarly, the cheapest way of saving energy is not to generate more clean power, but to ensure that this electricity is never needed in the first place through more efficient buildings.

This sort of whole-life thinking will be the bread and butter of BIM level 3, and will enable a future full of data-enabled collaborative working on projects that will maximise the use of the supply chain’s capability to deliver value to clients. It will allow us to create better performance-based project briefs with the means to prove compliance, and it will allow an unprecedented level of real-time control over a building’s assets.

Building services engineers are pretty unique as a profession because they can claim ownership of one of the biggest shares of data afforded by new smart technology – that produced by buildings and everything in them. It’s comparable in scope to that first wave of computers that dropped into engineers’ offices and changed our jobs forever. The opportunity is there, but it requires us to think more creatively about BIM and what it means if we are to grasp it.

The future of IT, circa 1992

Six months on from the second annual CIBSE Building Performance Conference and Exhibition, CIBSE Head of Sustainability Sara Kassam revisits one of the key topics from the two days: The ‘Built for Living’ panel. In this blog, she looks at the findings of the talk on well-being

Behavioural issues and their impact on the design of the built environment are an important topic for building services engineers and facilities managers, one where there is a definite appetite for better understanding, which was why it was a key area of focus at CIBSE’s Conference.

The event saw Professor Rhiannon Cocoran from the University of Liverpool consider how wellbeing is related to place; Professor Alexi Marmot from UCL look at factors affecting performance and productivity; and Polly Turton from Arup speak about how workspaces can be made more flexible and adaptable. Ann Marie Aguilar, also from Arup, give an insight into understanding behavioural responses to engineering and design.

The ‘Built for Living’ panel at the 2015 CIBSE Conference and Exhibition

Ann Marie Aguilar’s presentation focused on a report published by the Royal Academy of Engineering, the Economic and Social Research Council and consultant Arup. The document, Built for Living: Understanding Behaviour and the Built Environment through engineering and design, focuses on fostering good health and wellbeing, boosting performances and productivity and improving the stewardship of energy, water and waste.

The report is available to download at; it makes some interesting points relevant to those involved in the design and operation building services some of which are outlined below.

Good design is about developing an inclusive, user-centred solution which will work for the majority of a building’s occupants. However, a major challenge for designers looking to provide a user-centred focus is that there is no single agreed model of human behaviour that they can use.

There is no guarantee that occupants will use a building as designed

The situation at the moment is that engineers, facilities managers and architects all have different areas of knowledge and different experiences of the interrelationship of design and human behaviour, often at different stages in the lifecycle of buildings. Bringing together this knowledge has the potential to enrich designers’ responses. To this end, there is an opportunity to aggregate knowledge already in existence and to add to it through further research and post occupancy evaluation.

Since no single discipline or profession has all the necessary expertise a ‘Systems Thinking’ approach has been suggested as a way of enabling multidisciplinary collaboration. By helping identify how different parts of the system interact, designs can be developed to incorporate the complex interactions between buildings and the people that use them.

Some existing processes such as Soft Landings can provide a means for designers and constructors to enable a building to be designed to meet the end user’s needs. Soft Landings ensures occupant behaviour is included by involving the occupants at an early stage in scheme design. Participation is continued throughout the construction process and continues with involvement of the design and construction team beyond practical completion.

Buildings need to be considered as large systems interacting with other systems
including the occupants

User involvement is critical when considering the application of new technologies. Designers and engineers, for example, understand how it is technically possible to save energy in buildings through the use of particular technologies. However, what they often fail to consider is the importance of human behaviour and that users need to understand the purpose of the technology and how to use if the technology is to perform at its optimum capability.

Designers also need to be aware that the careful handover of a building is required to ensure the building works for them, while those maintaining the building understand how to actually make it work best for the users and to enable the building to perform to its maximum potential.

Eight practical principles for design have been proposed for use throughout a project, from architectural brief to final use. These are:

  • View human behaviour in the built environment as a complex socio-technical system
  • Use collaborative methods and tools to involve all key stakeholders, especially end users, throughout the design process
  • Include behavioural issues from the very beginning of the design process, in particular making the behavioural assumptions explicit at the outset.
  • During design, explicitly consider key characteristics of all users
  • Make it easy, fun and engaging to create and sustain good habits
  • Ensure the system gives users feedback at the right time and in the right format
  • Empower users to handle problems with the system as they occur
  • Learn and apply lessons from related domains

Incorporating these principles into a project should help improve design outcomes.

It is good practice to make engaging in good habits fun and engaging for occupants

As a proactive organisation CIBSE includes direction on the impact of occupant behaviour on the design of building services and the management of facilities in its guidance. In particular the recent editions of CIBSE Guide F: Energy Efficiency in Buildings and CIBSE Guide M: Maintenance Engineering and Management both acknowledge the potential impact of occupant behaviour.

Ultimately, people cannot be treated as components with predictable properties that can be engineered into a system because people often don’t behave in the ways designers expect. Instead, by increasing their focus on users’ behaviour building services engineers have an excellent opportunity to both improve the performance of buildings and the people in them.

The EU’s F-gas regulations are aimed at limiting their application and consequent emissions. Mike Nankivell, Chairman of the ACRIB F-gas group, gave a presentation on the latest update to the F-gas regulations at the recent CIBSE Building Performance Conference. Here he summarises the potential impacts of the latest revisions.

Although a year has passed since the government introduced tighter regulations on the use of Fluorinated gases (F-gases) to comply with EU’s F-gas regulations, the refrigeration and air conditioning industry is still struggling to come to terms with the impact of the latest changes.

The latest (2015) revisions to the F-gas rules strengthened existing measures in relation to containment, recovery, certification and sale of F-gases; introduces additional bans on usage; a ban the servicing of certain equipment with high global warming potential (GWP) F-gases; and more critically, a phase down of HFCs in the EU to 21% of a 2014 baseline by 2030. The revisions are intended to help further reduce emissions of fluorinated greenhouse gases, which are covered by the Kyoto protocol to limit global warming.

The air conditioning industry will have to adapt to the changes

The most common types of F-gas are hydrofluorocarbons (HFCs) which, unsurprisingly, contain hydrogen, fluorine and carbon. These are generally used in a variety of refrigeration applications including commercial refrigeration, industrial refrigeration, air conditioning and heat pumps.

The phase-down in HFC use is expected to have an impact on commercial refrigeration systems in particular because these systems tend to be charged with HFCs with the highest GWPs, for example, R404A which has a GWP of 3922. Under the new rules, from 2020 HFCs with global warming potentials of more than 2,500 will be phased-out in all refrigeration systems.

It should be noted that the phase-down still allows production of HFCs with a GWP lower than 2500 beyond 2030, and the regulation actively encourages recycling so it would be incorrect to presume that all HFCs will not be available beyond 2030. Where a system’s refrigeration charge is recovered and cleaned, or recycled, it will fall under a different section of the new regulation that will allow its reuse. Where this is the case, its re-use will not be determined by the phase-down process.

The most common types of F-gas are found in a variety of systems including heat pumps

As a result of the F-gas regulations, refrigerant producers now have maximum quotas based on equivalent CO2 emissions (CO2e) rather than limits on the quantities of specific refrigerant types. Because of this, the presumption is that the production of lower GWP refrigerants, such as R410A and R134a, may increase in the short term. Although, in the longer term, even HFCs with lower GWPs will likely be phased out if the industry is to meet the 21% target.

Unhelpfully for the air conditioning and refrigeration industry, in particular specifiers and installers, refrigerant producers are not making clear the likely availability of F Gases such as R410A or R134a in the next five-to-10 year period as the phase-down starts to make its impact felt.

Over time, as the phase-down continues, currently common refrigerants, such as R134a, will need to be replaced by ultra-low GWP options such as ammonia or CO2 or perhaps hydrofluoroolefins (HFOs). HFOs, Like HFCs, contain hydrogen, fluorine and carbon but as they are derivatives of alkenes they have significantly lower GWP than HFCs and are not included in F Gas quota system.

Installers do not know the likely availability of F-gases ten years down the line

When considering any replacement refrigerant, a variety of properties should be assessed including: operating pressure, energy efficiency, materials compatibility, toxicity, flammability and cost. One of the biggest challenges for manufacturers looking for replacement refrigerants is that many of the alternatives that are currently available do not perform as well in the same application as the HFCs they are intended to replace. Hopefully, this situation will change with future advances in the refrigeration technology.

In direct expansion (DX) systems, R32 would appear to be the preferred option to replace R410A despite the industry standard BS EN 378:2008 Refrigerating systems and heat pumps safety and environmental requirements placing a limit on the size of the refrigerant charge. Currently R32 is being offered as an alternative refrigerant in smaller capacity systems. However, a revised version of the standard, which provides scope to relax the charge limits, is currently out for approval. If the revisions to the standard are adopted, then R32 could be offered as an alternative to R410A in larger capacity DX systems including variable refrigerant flow (VRF) solutions.

It is worth noting that both R32 and HFOs are classed as ‘mildly flammable’. As a consequence, the revised version of BS EN 378 is set to include a new refrigerant category ‘A2L’ for such refrigerants.

Chillers are most likely to be affected by the new rules

Arguably, it will be chillers (charged with refrigerants covered by the HFC phase-down) and not DX systems that will be most impacted by the new F-gas rules. This is simply because the 25-year life expectancy of a chiller is greater than that of a DX system, which might be expected to last 15 years or so. At the moment it would appear that the safest choice of refrigerant for those looking to specify a chiller would probably be R134a, simply because R134a machines can generally be converted to use HFOs, which are not included in the F-gas phase-down.

The EU predicts the F-gas regulations will cut F-gas emissions by two-thirds by 2030, compared with 2014 levels. This legislation is aimed at stabilising CO2e levels of F-gas at roundabout the 100m tonnes by 2030. However, to achieve the EU’s roadmap of cutting emissions by 80-95% by 2050 additional measures will be required. This suggests that at some time in the not too distant future the industry can expect a further tightening of the F-gas regulations. You have been warned.