According to the NCVO Time Well Spent survey in 2023, the top three reasons why people continue to volunteer are: the organisation to which they contribute or help; the difference they make; and their commitment to the cause.

There is a whole range of benefits that can be gained from volunteering. These all ring true when it comes to CIBSE volunteers – day in and day out, their passion and drive to bring about positive change in the building services engineering sector is evident.

We recognise that prospective volunteers may face barriers, such as a lack of time, or concerns about not having the right skills or experience.

However, CIBSE strives to make volunteering accessible to all. There are many different ways you can volunteer at CIBSE, all of which can be found on the website, and there is always someone available to answer questions if you are unsure about which opportunity may suit you best.

While volunteers deserve recognition regularly for their efforts and contributions, the first week in June each year is Volunteers Week, which provides another good excuse to express thanks and highlight their work.

In 2023, the CIBSE networks delivered more than 360 events, which were attended by 10,500 members and non-members – but this is a mere drop in the ocean when it comes to the impact that volunteer-delivered activity has had on the operations of CIBSE over the years.

This point in the calendar also marks the end of AGM season, during which hundreds of volunteers are elected or re-elected to committee positions across the network. It is also a time when many stand down from the positions they have held for several years, although some stay on as committee members to impart their knowledge and experience. We are incredibly grateful for their contributions over many years.

After 21 years of service, Geoff Prudence recently stepped down as chair of the Facilities Management (FM) Group. His vital contributions during this time, including the support of the production of Guide M, have helped further the development of best practice within FM. CIBSE extends a special thank you to Geoff for his dedication over the years.

As we bid farewell to some of our wonderful volunteers, we also welcome many new faces to our team. While knowledge and experience are vital, new ideas and fresh enthusiasm are also essential to paving a way into the future for the committees and ensuring succession planning.

How our volunteers feel about their volunteer experience is also extremely important – feedback is the only way that we can look at what needs to be changed to make things run more smoothly in the future. Testimonials from volunteers highlight the diverse benefits of volunteering, from skills development to giving back to the industry and  inspiring others.

Joe Russell, honorary secretary of the Society of Public Health Engineers (SoPHE), says: ‘Through experience with the YEN [Young Engineers Network], I have developed a lot of useful skills that I was able to apply during my EngTech and LCIBSE application, as well as my membership of SoPHE application. The roles I have carried out have allowed me to build experience towards the criteria  required for these professional recognitions.’

Dr Maria Spyrou, Energy Performance Group immediate past chair and committee member, says ‘giving back to the industry that made me who I am, and inspiring young people to do more with their careers and ambitions’ are what appealed most to her about volunteering. And Hakeem Makanju chair of the Minority Ethnic Groups Panel, volunteers to ‘make a difference, give back and help support CIBSE’s vision, as well as to act as a role model’.

As Volunteers Week 2024 draws to a close, CIBSE CEO Ruth Carter has extended her thanks to all the Institution’s volunteers for their vital contributions. ‘Our volunteers are fundamental to the work that CIBSE does, and the impact that we have,’ she says. ‘Whether it’s authoring publications, being involved in committees, judging awards, or being a STEM Ambassador, there are opportunities, no matter where you are in your career.’

We would like to thank all of those who during the 2024 AGMs have stepped down from their roles on committees and highlighted below are those who have stepped down as Committee Chairs:

The post Gratitude and growth: celebrating CIBSE’s volunteers appeared first on CIBSE Journal.

The Badger Meter range of innovative water-quality solutions helps our clients from across the globe to safeguard water quality, for the protection of people and processes. Our class-leading water-quality portfolio provides actionable intelligence for the control, management and optimisation of facilities for water safety and sustainability.

As world leaders in smart water quality, disinfection monitoring and control, Badger Meter provides pioneering smart-sensor solutions for HVAC systems.

Continuous monitoring of water quality within HVAC systems plays a vital role in ensuring the long-term health and longevity of building networks, avoiding costly repairs, replacement or downtime. Fluctuations in pressure, pH and conductivity could indicate a leak or burst, or can suggest an issue with the chemistry of the water, where the additives added to kill bugs and germs have become compromised. Monitoring safe levels of dissolved oxygen also helps to maintain system health and prevents corrosion.

Even small changes in these water-quality parameters can, over time, lead to the deterioration of the HVAC system, which, if left unidentified, will require large-scale repair or replacement. Proactively identifying changes at an early stage helps to remove the risk of corrosion, while also, potentially, avoiding health issues such as outbreaks of legionella.

The unique ATi HVAC MetriNet solution from Badger Meter is one of the only monitoring instruments that can detect these subtle changes ahead of time, preventing long-term and costly damage. Flexibility is key with this class-leading system, with its modular nature allowing unique monitoring solutions tailored for individual site requirements.

At the heart of this MetriNet solution are the industry-leading digital M-Node sensors, which are connected to the water supply using a purpose-designed ‘click-connect’ flow-cell arrangement. Through the provision of live, continuous data, the HVAC MetriNet provides a constant health check and is key to protecting the lifespan of the HVAC system and the future of the building.

Discover more about some of ATi’s HVAC MetriNet installations and how the ultra-low-powered, smart digital sensor technology offers sustainable solutions, delivering proactive management to safeguard water quality and system optimisation in a variety of applications: Removing the Risk of Corrosion in HVAC Systems

Dissolved hydrogen sulfide (H₂S) monitoring in geothermal power plants and district heating networks

H₂S monitoring is crucial within geothermal power plants to ensure the safety of workers and nearby communities, and to protect the air, water, soil and vegetation in the surrounding environment.

Geothermal energy is generated by tapping into the heat stored beneath the Earth’s surface and is most prolific in areas of high volcanic activity, or where there are high levels of underground sulfur deposits.  Although it is a relatively clean and renewable energy source, high amounts of H₂S can be released throughout the process, which causes concern because of the potential toxicity and unpleasant odour.

Geothermal energy production in the Reykjavik area of Iceland continues to increase and the Department of Environment for Reykjavik city has been measuring H₂S since 2006, with levels expected to remain below 50 micrograms per cubic metre.

To ensure that the levels of H₂S comply with guidelines and remain within the required levels, managers at a leading geothermal power plant turned to Badger Meter for a class-leading solution.

Developed on one of Iceland’s largest high-temperature geothermal fields, this extensive site is one of the world’s foremost geothermal power plants, producing and supplying electricity and hot water for the district heating networks to Reykjavik.

As a global leader in water-quality monitoring, Badger Meter was delighted to be able to recommend the ATi Q46S/81 Dissolved Sulfide Autochem monitor. This state-of-the-art system continually measures the amounts of H₂S within the district heating water, offering peace of mind and ensuring health, safety and wellbeing for plant personnel and the people of Reykjavik, while also protecting and maintaining the natural beauty of the surrounding area for future generations.

Dissolved Sulfide Monitoring.

The post Intelligent solutions for safer water systems appeared first on CIBSE Journal.

F-gases in refrigerants are known contributors to global warming, and the EU F-gas Regulation 2024/573, which came into force on 11 March, aims to further curb the use of refrigerants with high GWP. The regulation mandates that, from 2027, chiller, air conditioning and heat pump systems under 12kW must have GWP limits of 150, and, by 2032, there will be a full F-gas ban in these systems. From 2027, larger split systems and chillers must have a GWP below 750.

This is part of wider plans to end the use of F-gas, with the EU parliament voting in January to phase-out HFCs, which make up 90% of F-gases, by 2050. This will be enforced by the reduction in HFC quotas set out in the revision of F-Gas III (EU) 517/2014. From 2025, the quotas allocated for HFCs by the European Commission will lead to a reduction of 22% compared with 2024, rising to 12% from 2036. This will result in price rises for remaining refrigerant, which the EU hopes will incentivise a move to low-GWP systems.

The UK is currently drafting its own legislation to align with these rules. It is expected to publish a stakeholders’ consultation document this summer, with a draft regulation published in the autumn.

The Net Zero Carbon Buildings Standard (NZCBS), due in the autumn, will also place limits on the GWP of refrigerants used. A consultation proposed a maximum GWP of 675, which is the GWP of R32, a common refrigerant. It also proposes that refrigerants be accounted for within embodied carbon calculations.

The regulations are driving demand for systems using natural refrigerants, such as ammonia, propane and carbon dioxide, which have near-zero GWP. This is the experience of Edoardo de Pantz, managing director at Acquaria, which manufactures propane (R290) heat pumps and chillers. ‘The market is running faster than the regulations are. The whole supply chain is asking for near-zero GWP heat pumps,’ he says.

BESA technical director and Institute of Refrigeration president Graeme Fox says the upcoming ban on high-GWP refrigerants has led to a sharp uptick in propane systems.

Propane has higher flammability than higher-GWP refrigerants, with an A3 safety classing, and Fox says installers will need to upskill to work safely with the refrigerant.

The EU F-gas regulations state that installers will need a refresher course within five years of the implementation date of the latest regulations (April 2029), and every seven years thereafter. But Fox notes that small systems with a GWP of more than 150 will be banned within three years – before the date when installers have to complete the course. He says manufacturers may stop supplying higher-GWP equipment, even before the implementation date

‘Technicians could be installing highly flammable refrigerants before they’ve had the necessary training, which is very much a concern to the industry,’ says Fox.

In response to the lack of awareness around propane, BESA has published a technical bulletin on R290 in air conditioning equipment and its practical application. Fox says R290 air-to-water monobloc heat pumps designed for housing need special consideration. The refrigerant’s flammability means it must be more than 1.5 metres from an openable window or door, according to manufacturers, says Fox, and because it is heavier than air, it must be more than 1.5m from air bricks and downpipes, to prevent leaking propane from infiltrating the house.

‘In most houses, you’re going to really struggle to get anywhere near the outside of that house and avoid an air brick by 1.5 metres either side of the unit,’ says Fox.

There are also implications for the retrofit of split air conditioning heat pumps in retail outlets or office applications, he adds. A typical application in these sectors is a grid of R407c condensers placed about 300mm apart, perhaps on a gable end. Currently, if one unit fails it can be replaced a similar unit, which is fairly straightforward.

However, it would be impossible to swap in a propane unit, because older units use A1-rated refrigerant that does not require Atex-rated electrical equipment, such as fan motors and electrical meters, so the neighbouring unit is a potential ignition source. (Atex is the name given to the two European directives for controlling explosive atmospheres.) ‘There are very serious implications for retrofit and retrospective repair work with the location of these new units,’ says Fox.

The issue can no longer be left to the AC contractor, he adds, because – under the Building Safety Act – the principal designer has to take responsibility: ‘They have to be aware of it.’

Currently, the European standard BS EN378 governs the safety and environmental standards of air conditioning, refrigeration, chillers, and heat pump systems, and this can be used with three EN60335 product standards that provide more specification details. Several CIBSE guides refer to BS EN378, including AM17 and Commissioning Code R, Guide B and Guide B3. A new version of the European standard is expected later this year (see page 13 to find out more about EN378).

An area Fox believes the EU has overlooked is the application of systems in airports, railway stations and military bases, where flammable A3 refrigerants cannot be used because of the danger of ignition – via sparks from trains and tracks, for example.

‘The EU has a line in the regulations that says higher-GWP refrigerants, such as 410a, can be used if safety standards don’t allow A3 refrigerants, but there’s no point having the exemption if you can’t get the equipment because the quota for these refrigerants is reducing so quickly,’ he says. ‘There needs to be a mechanism to bypass the quota and supply that equipment in these locations.’

For propane chillers, Fox says that – in addition to leak detection and good ventilation – the designer would have to ensure that fans, leak detectors, lights, switches and any power points are Atex-rated.

He is hopeful that issues identified with the latest F-gas regulation will be fed back into the UK’s upcoming consultation document.

‘Just because something is technically feasible doesn’t mean it’s practically applicable,’ he says. ‘We have to be aware of the nuanced application issues that engineers have on the ground.’ 

The post Safe and practical applications: natural refrigerants appeared first on CIBSE Journal.

As well as being a primary driver of climate change, cities are exposed to its negative consequences, and will have to adapt to extreme weather events, such as heatwaves and flooding. The vulnerable will be hit the hardest if society does not adapt to the changing climate. 

One of the greatest environmental risks to our health is ambient (outdoor) air pollution, which leads to increased levels of heart disease, lung cancer and premature deaths. Almost everyone lives in environments exceeding World Health Organization (WHO) guidelines³, and some of our children are exposed to pollution levels that lead to reduced lung capacity and lifelong breathing disorders⁴.

Air quality, and its effects, may also be affected by a changing climate.  It’s imperative that all routes to improving air quality should form part of a wider urban adaptation strategy.

In 2022, the UK Urban Environmental Quality (UKUEQ) partnership was established by the CIBSE Resilient Cities Group and UK Wind Engineering Society. Its aim was to help cities adapt to climate change by gaining a better insight into the urban environment – including air quality –  through the use of urban physics and digital tools such as computational fluid dynamics. UKUEQ now consists of more than 20 organisations from industry and academia.

Some of the key factors determining the quality of the environment include wind, air quality, thermal conditions and acoustics (see panel). Urban physics is about understanding how the ingredients of this urban soup interrelate and are affected by other elements, such as light, water, surfaces, drainage systems and the urban form (morphology), which alters the natural exchanges of energy and water between the surface and air. Ultimately, the multiple factors influencing the urban environment drive the resulting conditions within designers’ models. (See Figure 1.)

For example, as air speeds near the surface increase, more surface heat is exchanged with the air through convection. Conversely, at lower air speeds, more surface heat is exchanged with the surrounding surfaces and sky through radiation. It is therefore important to take wind and urban morphology into account when looking to improve thermal and air quality environments.

Unfortunately, our industry’s design disciplines tend to work in isolation, with little communication at the engineering level. There is a need for increasing collaboration and integration to improve safety and performance, and future-proof our cities.

Early design discussions that consider urban physics can lead to significant gains for the environment. The impact of decisions should be assessed during the various design development stages.

Knowledge gaps remain significant, impeding all practitioners’ ability to enhance societal resilience and address poor environmental, energy and health issues. So, what is being done to fill knowledge gaps?

To increase resilience, more research and development is needed to improve methods, technology, and overall sustainability⁵. Currently, as a building industry, we still experience failures and poor performance when we engage with new technology.

Overall, there is much to do to bring all aspects into a collaborative and integrated approach to solve the problems of the future urban environment. 

• The UKUEQ is a working group of the CIBSE Resilient Cities Group. It will be hosting mini-symposia at the University of Birmingham and University of Southampton this year, and will again be hosting a seminar at CIBSE Build2Perform Live, taking place at London ExCeL from 13-14 November.
• For more details on UKUEQ and its activities, see www.cibse.org/ukueq where you can access the full length version of this article

About the authors
Darren Woolf, chair of UKUEQ and the CIBSE Building Simulation Group, George Adams FCIBSE, CIBSE past president, and Stefano Cammelli, chair of the UK Wind Engineering Society

The authors would like to thank Ben Marner, at Air Quality Consultants, and Blaise Kelly, at TNO, for their contributions to the air quality sections.

References:

1. Zhao et al (2022). A global dataset of annual urban extents (1992–2020) from harmonized nighttime lights, Earth Syst. Sci. Data, 14, 517–534. DOI:10.5194/essd- 14-517-2022
2. Luqman et al (2023). On the impact of urbanisation on CO2 emissions. Urban Sustain 3, 6. DOI:10.1038/s42949-023-00084-2
3. WHO (2022). Ambient (outdoor) air pollution fact sheet.
4. Kings College London (2018). Air pollution restricting children’s lung development. https://www.kcl.ac.uk/news/air-pollution-restricting-childrens-lung-development
5. Alexander Clifford (2023). Understanding the role of R&D in the construction industry.
6. DEFRA (2016). NO2 fall off with distance calculator.
7. DHSC (2020). Chief Medical Officer’s annual report 2022: air pollution.
8. DEFRA (2022). Report: Non-methane Volatile Organic Compounds in the UK.
9. Mayor of London (2023). Air quality positive (AQP) guidance.
10. Mayor of London (2019). Using green infrastructure to protect people from air pollution.
11. DEFRA (2018). Report: Impacts of vegetation on urban air pollution.
12. DEFRA (2016). Report: Paints and surfaces for the removal of nitrogen oxides.
13. DEFRA (2022). Report: Indoor air quality.
14. Cammelli and Stanfield (2017). Meeting the challenges of planning policy for wind microclimate of high-rise developments in London. Procedia Engineering, Volume 198, 43–51.
15. City of London Corporation (2020). Thermal comfort guidelines for developments in the City of London.
16. Woolf, 2024. Cooking up an urban soup that tastes better. CIBSE Home Counties North West & Anglia Ruskin University seminar ‘Accounting for the urban heat island – Integrating multi-disciplinary perspectives for climate-responsive urbanism’, 18th January.
17. World Health Organization (2018). Environmental noise guidelines for the European region
18. Radicchi et al (2020). Sound and the healthy city. Cities & Health, 5:1-2, 1-13. DOI: 10.1080/23748834.2020.1821980

The post The urban emergency: addressing environmental quality appeared first on CIBSE Journal.

Secondary legislation regulations and guidelines are being used as the working values against which indoor air quality (IAQ) can be assessed.

It can be regulated via health and safety regulations, such as the Control of Substances Hazardous to Health (COSHH) Regulations (2002), to which all places of work have to adhere. Regulation 6(1) of COSHH states that an employer ‘should carry out a suitable and sufficient assessment of the risks to the health of your employees and any other person who may be affected by your work, if they are exposed to substances hazardous to health’. Regulation 10 of COSHH specifies that monitoring is required ‘when measurement is needed to ensure a workplace exposure limit (WEL) or any self-imposed working standard is not exceeded’.

There are legally binding WEL for around 500 substances, listed in HSE EH40/2005. However, WEL only relate to personal (exposure) monitoring of people at work, are calibrated for a healthy working-age adult, and can’t be readily adapted to evaluate or control prolonged, continuous or non-occupational exposure. So, for most office and education settings – and all public and residential buildings – WEL cannot be used to assess building occupant exposure to IAQ.

New buildings, however, are covered by the recently updated Statutory Instrument Building Regulations (2010). Now included in Approved Document F1 is ‘Means of Ventilation’, providing statutory guidance on ventilation requirements to maintain IAQ.

Within Approved Document F1, Appendix B: Performance-based ventilation, average indoor air pollutant guideline values are set for carbon monoxide (CO), nitrogen dioxide (NO₂), formaldehyde, total volatile organic compounds (TVOC) and ozone (O₃), largely based on World Health Organization (WHO) guidelines. However, as the document relates to building performance guidance, these values are performance criteria of the assessment of ventilation, not occupant exposure assessment criteria.

For several years, regulations, standards and guidance on IAQ for school buildings have been set out in the UK government’s Education and Skills Funding Agency Building Bulletin BB101. This includes guidelines on ventilation, such as setting a maximum CO₂ in teaching spaces, and specific guidelines on IAQ, mainly based on WHO guidelines that ‘should be used for schools’.

The WHO first published air quality guidelines in 1987, which have been updated since. They ‘serve as a global target for national, regional and city governments to work towards improving their citizens’ health by reducing air pollution’.

In 2010, the WHO published guidance on risks associated with pollutants commonly found in indoor air (benzene, CO, formaldehyde, naphthalene, NO₂, polycyclic aromatic hydrocarbons, radon, trichloroethylene and tetrachloroethylene), and updated their (general) air quality guidelines in 2021 (see Table 1).

It should be noted that WHO general air quality guideline values ‘do not differentiate between indoor and outdoor exposure’, so they are applicable indoors. Some of the latest 2021 guidelines supersede its specific 2010 IAQ guidelines (eg, for CO and NO₂).

They are relevant in all countries and in all exposure settings where COSHH WEL are not appropriate. Organisations, including CIBSE, point to these guidelines for IAQ monitoring. In recent years, other organisations have published IAQ guidance.

About the author
Oliver Puddle is technical director at DustScanAQ

The post The good, bad and illegal: rules and guidelines for IAQ appeared first on CIBSE Journal.

To ignore the ICSG’s guidance is to risk breaking the law, as the Building Safety Act – introduced in October 2023 – has competency requirements for all individuals and organisations working in construction, with few exceptions. 

The ICSG is chaired by Hanna Clarke, digital and policy manager at the Construction Products Association (CPA), who sat on the ICSG predecessor, the Competence Steering Group (CSG). This was set up by the Industry Response Group after Grenfell to look at competences of those on higher-risk buildings.

The CSG addressed competency shortcomings identified in the 2018 Hackitt review, Building a safer future (bit.ly/44Qc90o), and set up 12 working groups that – from June 2020 until October 2023 – published competency standards and frameworks for construction disciplines, including engineering.

Following its work responding to the Hackitt review, the CSG is now transitioning into the ICSG, which has a remit to develop new standards, competence frameworks, accreditation procedures and learning materials. The working groups will remain, to continue instilling competence in their sectors, but some have moved.

‘Two years ago, the Competency Steering Group decided that it needed to be long term and continue to work collaboratively with the industry on competency,’ says Clarke.

‘The CSG broke ground in bringing so many siloed sectors together in unprecedented collaboration. ICSG’s task will be to build on this, bringing in more disciplines and stakeholders, and increasing our engagement and visibility.’

The CSG created Working Group Zero, an oversight committee that looked at how competency would be regulated. Out of that came the Industry Competency Committee (ICC), which sets the competency standards and will be advising the Building Safety Regulator. The ICSG will look to raise industry standards and find where the gaps are in competency, says Clarke.

‘The ICC is like a mirror that is held up at industry, and it will challenge us,’ she adds. ‘We can give guidance and identify the areas where the problems are, and where we need support We’re looking to provide a much more joined-up approach.’

Defining competence

Hanna Clarke has gone from fine art to construction

The CSG published three reports, including Setting the bar (bit.ly/44ReBUC), which defined competence as ‘the combination of skills, knowledge, experience and behaviours that enable a person to undertake responsibilities and perform activities to a recognised standard on a regular basis’.

A similar definition is in the Building Safety Act: it requires ‘appointed individuals to possess the required skills, knowledge, experience and behaviours for their roles, while organisations must demonstrate and evidence their (and their supply chain’s) capability, competence and capacity to fulfil their obligations under Building Regulations’.

Clarke says the focus on behaviour is key: ‘Individuals must not work outside their ceiling of competence.’

She gives an example in the finishes and interiors sector, where a ‘Responsible No’ initiative (bit.ly/4buf812) is encouraging organisations to state when they are not competent to do work, rather than just saying ‘it will get the job done’.

‘The liability is now high if it’s seen that you are doing things that are outside of your demonstrable competence,’ warns Clarke. ‘If you say you can do something, you must back it up, whether you’re an individual or a team.’

Competency standards

Working Group Zero also led to the creation of a Code of practice for core criteria for building safety in competence frameworks, BSI Flex 8670.v3 (bit.ly/3WQCFFa). Flex is a more open approach to developing standards that allows feedback to be adopted by authors before the final standard is published.

Compliance with the standard can be achieved by mapping new or existing sector-specific frameworks against the core competence criteria and scope.

‘BSI 8670 is vital to know,’ says Clarke. ‘It’s a glorified checklist for the building safety principles you want to include in any competency framework. If any building services industry framework does not reference BSI 8670, the Building Safety Regulator will want to know why.’

The standard formed the core of the  UK Standard for Professional Engineering Competence and Commitment Contextualised for Higher-Risk Buildings  (UK-SPEC HRB) published by the Engineering Council. It sets out competences expected of engineers who work in the built environment sector, particularly on HRBs. Assessment to UK-SPEC HRB, and admission to the Engineering Council’s HRB Register, provides assurance to building owners that an engineer is competent to carry out work that complies with Building Regulations. CIBSE is one of three institutions licensed to award professional HRB registrations (bit.ly/CJHRBreg).

The flex standard will be published as BS 8670-1 and will sit alongside BS 8670-2 (bit.ly/CJBS86702), which is a standard being developed by Working Group 12, the products group. It will feature the core requirements for construction product’s competencies and frameworks, and is based on a CPA white paper authored by Clarke, Built environment – proposed construction product competence standard.

There are five levels of competence for a range of activities, such as product performance. Levels are graded from E to A, and someone with the highest level of competence can understand the systems and rules, and sign off the product. It means organisations can communicate the levels of competence at which designers and installers are working to the rest of the industry.

A new BSI technical committee, CPB/1 Competence in the Built Environment, manages standards output and has published PAS documents for the two dutyholder roles defined in the Building Safety Act – principal designer (PAS 8671) and principal contractor (PAS 8672) – and a PS 8673 for those managing safety.

Clarke has an unusual background for someone working in building safety. She has a fine arts degree and was an exhibiting artist when she got interested in construction processes while temping at a facilities management company. ‘I was an administrator, but I got curious,’ she says. ‘I kept asking questions about whether we’d done this right. I got into compliance and then data architecture, and started building planned maintenance systems for different buildings.’

She joined the CPA as an executive assistant and project coordinator, and became involved in the competency steering group. ‘The irony of this whole journey is that I can prove my competency to no-one,’ she says. ‘My competence is in asking people a lot of questions and saying “have we thought about this”.’

About the author
Hanna Clarke is digital and policy manager at the Construction Products Association

The post ‘Asking the right questions’: meeting building safety requirements appeared first on CIBSE Journal.

As in the past few years, CIBSE has reviewed last year’s awards entries to assess building performance across the projects, as well as the quality of the information provided.

In 2021, based on a review of all past entries, CIBSE introduced a data form to accompany the Project of the Year entries, to improve the consistency, quality and coverage of the building performance data provided.

This helps the judging process, and contributes to industry’s understanding of current best practice, in turn feeding into CIBSE activities such as the Net Zero Carbon Buildings Standard (NZCBS).

Since then, entries have been reviewed every year, and updates made to the data forms to reflect evolving practice and improve clarity and data collection.

Quality of data

This year’s analysis confirms that the quality and scope of building performance data continues to increase. The award entries show fewer areas of data uncertainty, more consistent information, and wider coverage of building performance.

While a large proportion of buildings entered into the awards have onsite generation, the energy flows associated with the building and onsite systems are better reported than in previous years. This indicates better metering set-ups, as well as better monitoring and analysis.

SGA Consulting was crowned CIBSE Building Performance Champion for its retrofit of York Guildhall

In recent years, few entries had complete and reliable enough data to estimate the building’s energy use intensity (EUI) with reasonable confidence, but, importantly, this is now possible for the majority of entries.

What the data tell us

Last year’s data shows trends in delivery processes applied across the projects, similar to previous years. As expected, projects often used energy performance modelling (rather than just compliance modelling) – for example, Passive House Planning Package (PHPP) or CIBSE TM54 more generally. Many of them set energy performance targets beyond regulatory compliance, sometimes as contractual targets. They carried out post-occupancy evaluation, with attention to energy use as well as factors beyond it, such as indoor air quality, temperature monitoring, and interviews or surveys of occupants.

The new-build entries had lower energy use than the average building stock, sometimes significantly so; however, energy use was still higher than industry targets from the RIBA 2030 Challenge and LETI for the sectors where these targets are most established, such as homes, offices and schools.

In future years, the NZCBS, due for beta release later this year, will provide a further point of comparison, applicable across a wide range of sectors.

The majority of projects, and all the new-build ones, had onsite photovoltaics (PVs) – in some cases with significant export as well as self-use. The contribution of these PV systems varied significantly across projects, on average around 60-70kWh/m² per yr building footprint (ranging from 35 to 140), covering, on average, around 30% of the building’s annual energy use (ranging from 5% to 55%).

For comparison, in last year’s Technical Update Consultation, the NZCBS proposed an approximate target range of 80-120kWh/m² per yr for non-industrial buildings; this was only a draft and is being reviewed ahead of the beta release.

CIBSE looks forward to your entries, and wishes you all the best of luck!

To enter visit www.cibse.org/bpa

The post Building on performance: CIBSE awards analysis appeared first on CIBSE Journal.

This landmark 10,500m² building, hidden behind a giant green wall of 350,000 plants, is the first new build scheme to achieve a Nabers UK 5.5-star ‘Design Reviewed’ target rating for landlord energy consumption. Its designers also set out to minimise upfront embodied carbon. The as-built figure of 620kg CO_2e.m^-2 is impressive given that, when it was designed in early 2020, there were ‘no targets and no definition for 90% of what we were talking about’, says Wyatt.

The building has been developed by ECF (formerly The English Cities Fund), a joint venture between developer Muse, Legal & General and Homes England. Its outstanding green credentials are the result of a committed developer and it being the first scheme to be built to Muse’s sustainable development brief, which Cundall helped draft.

‘We worked with Phil Marsden, from Muse, from RIBA Stage 0, to help set the brief for the entire design team at the beginning,’ says Wyatt. ‘We set clear objectives, aspiring to achieve the lowest carbon, the best health and wellbeing, and the best biodiversity increase we possibly could’.

The building’s holistic sustainability strategy means that it is Well Building Standard-enabled. Wyatt says this will ensure its tenants can achieve Well certification with their category B fit-out and its subsequent operation. ‘We went through a fit-out pre-assessment, so the landlord has already obtained 20-30% of the credits needed for any occupier coming to Eden who is looking to Well certify,’ he explains.

Wellbeing features incorporated into the landlord’s design encourage tenants to use the stairs, rather than take the lift, by incorporating daylight into the stair core and locating it so it’s easily accessible from reception.

Fresh air supply rates have also been increased on the office floors. The building’s location on a major road junction precluded the use of openable windows, so it has a full mechanical ventilation system. At the time of its design, most commercial offices had a fresh air rate of 12L.s^-1 per person, but, at Eden, this has been increased to 16L.s^-1 per person, which, Wyatt says, gives much better air quality.

A 4-pipe fan coil system is used to maintain comfort on the office floors, with heating and cooling provided by roof-mounted air source heat pumps. The fan coil units are supplied with fresh air ducted to the rear of the units from roof-mounted air handling units (AHUs).

The increase in fresh air supply rate enables an element of free cooling to be provided by the AHUs. ‘Too much air and you have an energy penalty, but a 16 L·s^-1 per person, the balance is about right; you get an energy increase for the fans, but you get an energy benefit from the free cooling,’ explains Wyatt.

Cooling loads have been kept low by the designers adopting a small power load of only 8W.m^-2. At the time, the British Council for Offices’ (BCO’s) recommended a small power load of 25W.m^-2, based on historic technologies, which, Wyatt says ‘would have caused everything to be oversized and to work inefficiently’.

The ‘punched’ windows allow the building to achieve good daylight levels on the office floors

To come up with the more appropriate small power load, Cundall worked with the project’s MEP concept engineers, Atelier Ten. ‘We convinced Muse to very bravely go for 8W.m^-2, which is enough to power a laptop and monitor,’ says Wyatt. Adopting this lower figure meant that, when the building was first marketed, it was not BCO-compliant. However, the BCO has subsequently updated its guidance to 6W.m^-2.

In addition to allowing for a reduced small power load, the design cooling loads are also kept to a minimum by the building’s envelope. This eschews curtain walling in favour of a solid façade with what Wyatt calls ‘punched’ windows, as opposed to using full-height glazing.‘We said we wanted to achieve an overall façade U-value of circa 0.6 to 0.65W.m^-2.K^-1, which is very challenging to achieve with curtain walling,’ says Wyatt. This has resulted in a façade where the solid areas have a U-value of just 0.15W.m^-2.K^-1, while the windows have a U value of 1.4W.m^-2.K^-1. Airtightness is 2m³.h^-1.m^-2 @ 50Pa.

What gives the building its unique appearance is that the solid elements of the façade are covered by a living wall of 350,000 plants. These form a surround to the windows and, because they are visible from inside the building, Wyatt says they contribute to biophilic health and wellbeing. Other benefits of the green wall include: contributing to the area’s biodiversity; absorbing pollution; reducing the urban heat island effect; and helping to lower the air temperature slightly around the heat pumps, which improves their performance.

In terms of cost, Wyatt says the façade was cheaper than a lot of other systems because, behind the greenery, it is ‘a very basic system’. There will be ongoing maintenance costs, however.

Daylight levels on the office floors are also based on Well criteria, rather than on daylight factor. The office floors are described by Wyatt as ‘reasonably narrow’, but through careful design, the punched window solution achieves good daylight levels.

Climate-based daylight modelling was used to optimise the location of the façade’s 40% glazed area. ‘We did a lot of solar modelling of the façade; we’ve distributed the glazing so there is slightly less on the south and slightly more on the north, to help create uniform daylight distribution,’ explains Wyatt.

Optimising the position and area of glazing, combined with additional shading from the green wall, helps keep solar gains to a minimum. To ensure the offices are comfortable, the fan coil units are controlled zonally, based on four zones per floor. At the time the scheme was designed, Wyatt says a lot of commercial offices were designed to maintain an internal temperature of 22°C, with very little leeway, which meant simultaneous heating and cooling could occur on the same floor plate. For Eden, the heating setpoint is 20°C, while the cooling is set at 25°C.

Wyatt is keen to explain that, even with a 5K dead band, there is no compromise on comfort because the scheme has been designed based on maintaining the operative temperature, which is a combination of air temperature and radiant temperature. He says spaces with full-height glazing often have a high radiant temperature, so a low air temperature is required to maintain a comfortable operative temperature.

The green wall of 350,000 plants incorporates automatic irrigation, fed using rainwater harvested from the building’s roof

At Eden, optimising the glazed area and incorporating a green wall has helped reduce radiant temperatures in the offices, enabling the air temperature to be elevated while still maintaining a comfortable operative temperature. ‘Even though we have a higher air temperature within the space, the operative temperature is the same or better than that of a fully glazed office building,’ Wyatt explains.

The higher air temperature in the offices is just one element of the building’s outstanding low-energy design that has helped it achieve a Nabers UK 5.5-star ‘Design Reviewed’ rating. Nabers is the energy efficiency rating system that is gaining traction because a commercial office’s predicted energy performance is subsequently verified once the building is operational, through annual energy consumption monitoring.

Wyatt says experience from Australia (where Nabers originated) shows that, when a building is first occupied, its Nabers rating is expected to drop by about one star. ‘The idea is that the rating improves over a couple of years as the building is fine-tuned,’ he adds. ’According to the Better Buildings Partnership, we can probably expect a half-star incremental increase each year; so, if we achieve 4.5 stars in the first year, we would expect 5 stars in the second, and 5.5 stars in the third, which would be a really positive story.’

Cundall is already working with some of the building’s future tenants to ensure they don’t compromise the Nabers rating. Alongside the tenants, Wyatt says one of the greatest challenges was ‘ensuring that requirements for operational energy, embodied carbon and biodiversity net gain were written into the building contract in a meaningful way, with a clear methodology for measuring, reporting and certifying performance in use’. This meant providing contractor Bowmer + Kirkland with evidence that the design would work. Bowmer + Kirkland will update the rating using as-built information now that it is complete.

Wyatt says a key lesson from this project is that bringing the Nabers independent design review forward from RIBA Stage 4 (technical design) to Stage 3, when designs usually go out to tender, would give contractors more confidence in the operational energy requirements, although this means doing the calculations and simulation much earlier.

Once fully occupied, Eden will be enabled to run solely on 100% renewable electricity, which will further enhance its already outstanding sustainability and wellbeing credentials. 

About the author
Simon Wyatt MCIBSE is a partner at Cundall and chair of the CIBSE Knowledge Generation Panel

The post Case study: Manchester’s garden of Eden appeared first on CIBSE Journal.

The LSBU research uses a degree-day approach based on CIBSE Technical Memorandum (TM) 41², while Parity Projects is exploring Reduced Data SAP-related methods. Both models ultimately want to be able to show whether a heat pump is performing as expected, and whether under-performance can be explained in terms of system deficiencies, weather anomalies, or user behaviour.

The project has installed remote-monitoring systems into 18 houses – mainly older detached properties – with a target of 40 houses to be monitored by the end of the project. Each house has temperature sensors in selected rooms (typically four or five), heat meters for space heating and hot water (where appropriate), and gas and electricity data collection. Weather data is collected via dedicated local weather stations or from commercial sources of local weather.

TM41 describes a degree-day-based approach to estimating and monitoring space heating energy in buildings. It incorporates building heat loss coefficient, building thermal capacity and casual gains – together with operational factors such as occupancy profiles and control strategies – to capture quasi-dynamic energy performance against external temperature conditions. The complexity of energy modelling is reduced while a degree of mathematical rigour is retained. It modifies the classical degree-day approach by incorporating daily mean internal temperatures and casual heat gains into the degree-day calculation, to give building-specific base temperatures. The degree-day values can be used for performance measurement or future energy estimation – the former for building characterisation, the latter for energy use predictions.

This project examines how well the method works at different timescales – daily, weekly and monthly – and its accuracy using the high-quality data sets from the monitoring process.

Theory and method

Daily degree-days are the sum of the temperature difference between indoor base temperature and the hourly outdoor temperatures:

D_d=Σ(θ_b – θ_o,h) Δt

Where the base temperature, θ_b, is calculated from

θ_b = θ_i – Q_G/HLC

Where θ_i and Q_G are the mean daily internal temperature and mean daily gains respectively (kW), and HLC is the heat loss coefficient (kW.K^-1; including both fabric and infiltration components).

Ε =24. HLC. D_d/η

 Where E is the energy consumed for space heating (kWh) and η is the system efficiency (or coefficient of performance (COP) in the case of a heat pump). E can be plotted against D_d to analyse the energy performance of an existing building. In theory, the slope of a regression line of E v D_d is equal to the term 24.HLC/η.

This principle can be used to estimate the heat loss coefficient of a building and/or the system efficiency. The HLC used to generate the base temperature can be adjusted until it agrees with the slope of the regression line. This can be a far more reliable way to determine the actual heat loss characteristic of a building than from a physical survey. However, this principle only holds true if the correct base temperature is used in calculating degree-days, which will depend on knowledge of actual gains into the space. The research questions that arise are:

• What is the minimum amount of sensor deployment and data collection required?
• Which timeframe is most appropriate (daily, weekly or monthly) in terms of accuracy and data handling?
• Can the regressions be used to identify system-, weather- and behaviour-based anomalies?

Effect of timeframe

There are a number of ways to examine timeframe, particularly whether degree-days should be calculated to daily-varying base temperatures or whether longer-term averages can be used. In theory, the more fine-grained the better, but, in practical terms, long-term averages are easier to use because they require less granular data. The full paper examines this in more detail, and the example below shows one case where daily base temperatures are used for all timeframes. The example shows a detached house heated with a gas-fired combi boiler. Delivered space heating energy (from the heat-metered boiler output) is plotted against degree-days for daily, weekly and monthly timeframes. Note that the slope of this line is directly related to the heat loss coefficient (HLC=slope/24 kW.K^-1). Two observations can be made between timeframes:

1. The scatter reduces as the data is aggregated into longer timeframes and the R² value increases markedly. Outliers at the daily level tend to disappear, which, in this case, can be explained in part by short periods where the system was switched off, but then took some days to warm the building back up. Losing these outliers can mean losing operational insights.
2. The slope of the regression lines increases as the timeframe gets larger (and the intercept, which in theory should be 0, reduces). This is a trend across all buildings analysed to date, and is a characteristic of linear regression that needs to be fully understood. The current working hypothesis is that the daily timeframe gives the most reliable estimate of the heat loss coefficient because it contains more information about gain and internal temperature variations.

Case study – heat pump retrofit replacing oil boiler

The case study house has a 18th-century core with some additions and upgrades, and cavity-wall insulation and double glazing. It originally had oil-fired central heating, which was replaced with an 11kW air source heat pump. An in-line oil flow meter was fitted to the boiler just over one month before the heat pump installation. Prior to that, oil usage was measured from a 10-step oil gauge and quantities of bulk oil deliveries.

Figure 2 shows 39 days of oil meter data against daily degree-days to daily base temperatures. The R² value is poor, and the slope (together with an assumed boiler efficiency of 0.85) indicates an HLC of around 0.26kW.K^-1. This is lower than the surveyed estimate of 0.36kW.K^-1. The intercept of 30.4kWh per day is high given that daily domestic hot water energy from summer use has been shown to be around 21kWh per day. Note that an analysis using bulk oil delivery returns an HLC of 0.346kW.K^-1, considerably closer to the calculated value. This example indicates the difficulty of obtaining reliable baseline data from oil boiler installations, even if in-line meters are fitted (which is rare).

The heat pump was installed in March 2023, with integral electricity and heat metering. Figure 3 shows daily delivered space heating against daily degree-day to daily base temperatures for one entire heating season. The regression optimisation shows a slope of 8.88kWh per Dd, or 0.37kW.K^-1, which is 7% higher than the previous oil regime analysis. The relationship is markedly better than for the oil boiler, indicating that the heat pump system employs a better control regime. Many of the outliers above the line can be shown to be because of weather events (in this case high winds from the south).

Figure 4 shows the daily electricity used by the heat pump for space heating. It is apparent that a simple linear regression (straight line relationship) is not sufficient here because of the large variation in COP across the heating season (possibly up to +/-30%), particularly in colder weather. A second-order polynomial is shown to be a good fit.

The regression equations for Figures 3 and 4 respectively can be used to develop a plot of expected heat pump COP for a given value of daily degree-days, as shown in Figure 5. This can be used to monitor the heat pump performance and identify system faults, or control anomalies by comparing with daily COPs in real time.

The preliminary results show how a TM41 degree-day approach can be used to characterise the thermal energy performance of a house, and form the basis of performance monitoring and anomaly identification. The next step in the research is to refine the predictive model for heat pump retrofits and validate the method using the range of properties being monitored in this study. The aim is to develop a set of rules by which regression models can be used to identify and explain system failures, user actions, or unusual weather events.

It is important that energy forecasts and performance monitoring methods are reliable and understandable to the householder, particularly where performance guarantees are in place. High levels of trust will be required where retrofit financing is funded through loans or operational savings and underpinned by such guarantees. 

About the author
Tony Day FCIBSE is an energy research consultant

• This paper was presented at the 2024 Technical Symposium

References:

1. Heat pump-ready programme: Stream 2 projects, Department for Energy Security and Net Zero, viewed 20 November 2023,
   bit.ly/3QQP6gm
2. TM 41 Degree-days: Theory and practice, CIBSE, 2006 bit.ly/44QzwXS

The post Predicting heat pump performance: a simplified analysis appeared first on CIBSE Journal.

This groundbreaking scheme sets a new benchmark for zero carbon educational buildings – an achievement acknowledged at the 2024 CIBSE Building Performance Awards, where it won Project of the Year – Public Use. The judges said the design team met the brief with an exceptional design that successfully combined ‘high-performing building fabric and high-performing engineering services’.

The school’s exemplary eco-credentials responded to the client’s ambitious ‘One Planet Living’ brief and were supported by planning requirements. Its location, between a conservation wetlands area on Metropolitan Open Land and the pioneering BedZED eco-village, meant that the school had to be zero carbon in operation, effectively, to gain planning approval.

Architype, the scheme’s architect and Passivhaus designer, suggested the Passivhaus Plus standard. ‘In 2014, we said, if you want to get this over the line with the planners you need to say you’re net zero, and the only way we believe you can demonstrate that is through Passivhaus Plus,’ says Christian Dimbleby, an associate at Architype, which worked with engineer Introba to develop the scheme.

The school stands on a shallow, insulated, concrete-raft foundation, incorporating ground granulated blast-furnace slag – a by-product of iron production – as a binder to lower the slab’s embodied carbon.

Its foundation is the only major non-timber element in the two-storey school’s construction. The entire superstructure, walls, roof, composite window frames, first-floor slab and cladding are all formed from timber, after Architype used ECCOlab software (an energy, carbon and cost calculator) early in the design process to select materials with low embodied carbon.

To further reduce emissions, all soil excavated during construction has remained on site and has been used to create grass mounds that surround the playgrounds.

To minimise future embodied carbon emissions, partitions between rooms are designed to be moveable, to allow spaces to be easily reconfigured as the school evolves. Similarly, the school is designed to be extended easily to accommodate an increased pupil intake, without the need for reconfiguring the existing structure or major interventions on the building services.

‘We’ve designed the building so the circulation spaces, assembly hall and plant work for a two-form entry,’ says Dimbleby.

The west, east and south elevations of Hackbridge Primary School

As a Passivhaus building, the L-shaped school has a highly insulated and airtight envelope, to minimise fabric heat losses, control heat gains and provide excellent levels of comfort. The large school hall is positioned facing east-west and serves to help block traffic noise from the nearby main road. The hall shelters the adjoining classroom wing, which faces north-south to optimise solar gains.

Brise soleil and an oversailing roof provide shade to the southern elevation to prevent the classrooms from getting too warm in summer, in compliance with Passivhaus overheating criteria and CIBSE TM52.

‘We did a lot of work with Introba on optimising window positioning and sizing,’ Dimbleby explains.

Classrooms have mixed-mode ventilation, allowing teachers to open windows when conditions are suitable.

In winter, heating is provided by an ICAX 70kW ground source heat pump (GSHP) system. This extracts heat from the ground via eight, 130m-deep boreholes and stores it at 42^oC in a 300-litre thermal store.

A low-temperature hot water circuit, operating at 42^oC flow/37^oC return, supplies low-temperature radiators in the classrooms and an oversized heating coil in the air handling unit (AHU).

‘One of the benefits of Passivhaus levels of fabric insulation is that we didn’t have to locate the radiators under the window,’ says Graham Day, associate principal engineer at Introba.

The school meets LETI embodied carbon targets

Using the ground as an interseasonal heat store enables the boreholes to provide cool water to temper the fresh air supply in summer. In this mode, the heat pump is bypassed so that ground-temperature water (at about 10^oC) is circulated to the AHU cooling coil. Coolth is also recovered from exhaust air by the AHU’s thermal wheel.

‘While we’re extracting coolth from the ground we’re warming it up, which helps the heat pump operate more efficiently in winter,’ Day explains. Because supplying cooling only requires a very small amount of power to run the circulating pumps, it is beneficial to do so, adds Day, because it enables the heat pumps to work more efficiently in winter. ‘It is better than free cooling – it is beneficial cooling,’ he says.

For optimum system performance, annual heating and cooling loads should be balanced, so the heat removed from the ground in winter is put back in summer. ‘On this scheme, we’ve not managed to achieve a precise balance, but there is still a beneficial heat exchange,’ Day says.

Opening windows are key to the Passivhaus strategy

A separate 40kW heat pump connected to the same borehole array is used to preheat the domestic hot-water thermal store to 52^oC. A gas-fired water heater is used to provide top-up heat to the vessel and is available to provide backup to the heating system. ‘Improvements in technology mean that, if we were designing the system today, we’d be able to heat the domestic hot water entirely by heat pump,’ explains Simon Ebbatson, senior principal at Introba.

The temperature in the domestic hot-water network is maintained using a conventional circulation system, but with microbore pipework connections to individual taps.

‘Passivhaus penalises you heavily on dead-leg lengths, so we’ve designed the system to ensure there is no more than a litre of water in any one of these,’ says Day.

To achieve Passivhaus Plus, the school must offset all energy use over the course of a year, including unregulated loads. To do this, it incorporates 424m² of photovoltaic (PV) panels, designed to deliver 81kWp. The panels are supported on frames above the green roof, where a symbiotic relationship means that panels provide shade to the vegetation, while transpiration from the vegetation and evaporation from the growing layer,help cool the panels, improving their output.

Figure 1: EUI of Hackbridge Primary School compared with CIBSE typical and good practice, and LETI school benchmark

The downside of using PVs to achieve an energy balance on a school is that the panels provide the highest electrical output on summer days, when the school is closed. While the school can sell this surplus electricity to the Grid at a relatively low price, it does still have to buy electricity from the Grid at a much higher price to make up for the electricity shortfall on shorter, darker winter days. The school achieves an annual energy balance, but there is still a net cost for electricity. ‘Unfortunately, achieving an energy balance does not necessarily result in a financial balance in today’s market; we hope this may change in future,’ Day says. See Figure 1 for energy performance data.

The school received its first intake of pupils just before the Covid pandemic, which hindered its operational optimisation and, subsequently, its ability to achieve net zero energy in operation. There were also issues with a faulty buffer vessel and three of the photovoltaic inverters failed. School staff, too, struggled to come to terms with the nuances of running a Passivhaus Plus school – for example, knowing when to open the windows and when to take advantage of free cooling.

To their credit, the engineers and architect have remained committed to the project and have continued to be involved through a voluntary soft landings arrangement. In addition, contractor Willmott Dixon has implemented its Energy Synergy process, to measure and verify the school’s operational energy use by comparing metered data against monthly Passive House Planning Package (PHPP) targets, which has helped highlight some anomalies. For example, a building management system (BMS) demand signal to the GSHP stopped working after a software update to the BMS. This was picked up by a sudden increase in gas consumption.

The team’s perseverance has paid off; four years after the school opened, the latest sub-metered data shows energy consumption and generation is very close to the PHPP design targets and on track to achieve net zero energy (see Figure 1).

This pioneering school is finally living up to its A+ Energy Performance Certificate billing. With an energy use intensity of 42kWh.m^-2 per yr, Architype says the school exceeds RIBA’s 2030 operational targets and, with upfront embodied carbon with sequestration of 405kg CO₂e.m^-2, meets LETI’s 2020 embodied carbon targets. 

The building’s impressive green credentials are used to enrich the school curriculum and bolster environmental awareness among the pupils. This makes it a great example of how we can embed environmental design in our school buildings and inspire the next generation.

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