In the UK, on average people spend more than 90% of their time indoors.
Indoor air quality is affected by outdoor pollution, but also by indoor sources and inadequate ventilation. Air pollution can have a negative impact on our health; from short term effects such as eye irritation and coughs to long term effects such as respiratory infections and cancer.
Here, we take a look at contaminants commonly found in buildings. For more information on how to manage indoor air quality, please visit the BSRIA Air Quality Hub.
Carbon Dioxide
A colourless and odourless gas resulting from combustion and breathing. At higher concentrations carbon dioxide can cause drowsiness, fatigue, and dizziness as the amount of oxygen per breath is decreased. In an enclosed environment, ventilation is key to reduce carbon dioxide build-up.
Carbon Monoxide
An odourless and colourless gas produced by incomplete combustion of fuels such as oil, wood, and gas. Carbon monoxide binds with haemoglobin in blood cells instead of oxygen, rendering a person gradually unconsciousness even at low concentrations.
Ozone
Whilst beneficial in the stratosphere, when found at ground level, ozone causes the muscles found in the respiratory system to constrict, trapping air in the air pockets, or alveoli. Ozone can be produced by certain air purifiers, laundry water treatment appliances and facial steamers.
Particulate Matter 2.5
A complex mixture of solid and or liquid particles suspended in air, where the diameter of the particles are 2.5 microns or smaller. PM2.5 sources include transportation, power plants, wood and burning and can cause airway irritability, respiratory infections, and damage to lung tissue.
Particulate Matter 10
A complex mixture of solid and or liquid particles suspended in air, where the diameter of the particles is 10 microns or smaller. PM10 sources include construction sites, industrial sources, and wildfires. These inhalable particulates can obscure visibility, cause nasal congestion, and irritate the throat.
Formaldehyde
A colourless gas that is flammable and highly reactive at room temperature. Formaldehyde is a carcinogen and a strong irritant. Formaldehyde can be found in building materials, resins, paints, and varnishes and can last several months particularly in high relative humidity and indoor temperatures.
Total Volatile Organic Compounds
Carbon-based chemicals that easily evaporate at room temperature, most commonly found in building materials, cleaning products, perfumes, carpets and furnishings. Long term exposure can cause, cancer, liver, and kidney damage whilst short term exposure can cause headaches, nausea, and dizziness.
by Dr Aaron Gillich | Associate Professor and Director of the BSRIA LSBU Net Zero Building Centre
We have entered what many are calling the decisive decade on climate action. Among the most critical decisions that the UK faces this decade is how it will eliminate carbon emissions from heat. Heat accounts for over a third of our emissions, and over 80% of our buildings are linked to the gas grid. There is no pathway to Net Zero that doesn’t include ending the use of gas as we know it in the UK.
Given the size of the UK gas grid, no single technology or energy vector can replace it. We will need a combination of clean electricity and carbon‐free gas such hydrogen or biogas, delivered by a range of enabling technologies such as heat pumps and heat networks. And of course an extremely ambitious retrofit agenda that reduces the demand for heat in the first place.
The UK is investing widely in low carbon heating innovation. That innovation is essential, but is also unlikely to include any blue‐sky breakthroughs that aren’t currently on the table. In other words, the menu of low carbon heating technology options is set, and this decisive decade will be about deciding what goes best where, and how to ensure a just and equitable heat transition.
Low-carbon heating options
Of all the low‐carbon heating options available, low carbon heat pumps are the most efficient and scalable option that is market ready and can respond to the urgency of climate change this decade. The UK has set a laudable target of installing 600,000 heat pumps per year by 2028. Many have criticized this figure as unrealistic, but I believe that the target is highly achievable, and represents a pace that is in line with past transitions such as ‘the Big Switch’ that put us on the gas grid in the first place.
This race to replace gas in the UK has been widely discussed. As have the many barriers that face heat pump deployment in the UK. What I’ve heard discussed far less are the links between heating in the winter and overheating in the summer. Over the next decade, the end of gas will present both a threat and an opportunity to improve both the winter and summer performance of our building stock.
The threat of climate change is clear. The end of gas increases this threat because gas has allowed the UK to obscure poor building performance, and poor building knowledge for so long. Cheap gas has enabled a ‘set it and forget it’ approach to many building systems, and allowed us to maintain reasonable standards of comfort in most buildings despite very poor fabric performance. The irony is that this poor winter performance actually helps reduce the risk of overheating in the summer, as the leaky and poorly insulated buildings can more easily shed excess heat. It has been widely reported that many newer, better insulated buildings actually face an increased risk of summer overheating.
Replacing gas with heat pumps, or any other low carbon heat source, should be accompanied by ambitious retrofit to improve energy efficiency and reduce heat loss. There are many that argue heat pumps in fact require extensive fabric retrofit in order to function in most UK buildings. This is highly debatable and will be explored in detail in follow-up writings. Regardless, demand reduction and a fabric first approach is a good idea for its own sake.
Replacing gas with heat pumps, or any other low carbon heat source, should be accompanied by ambitious retrofit to improve energy efficiency and reduce heat loss.
But reducing the heat loss in winter will likely trap heat in the summer, presenting a conflict. The UK currently experiences over 20,000 excess winter cold deaths and around 2,000 heat related deaths in summer. It was previously thought that the increased temperatures from climate change would decrease winter cold deaths, but more recent work has shown that due to the increases in extreme weather events at both ends of the spectrum, it is far more likely that winter cold deaths will remain at similar levels, and summer heat deaths will increase dramatically under climate change.
We must use the transition from gas to low carbon heating as an opportunity to better understand our buildings. Many of 600,000 heat pumps we install by 2028 will be in new build, but up to half will need to be from existing homes.
Retrofitting a heat pump is also the time to think about not only how to improve energy efficiency for the winter but how to reduce summer overheating as well. Despite much effort towards a whole‐house approach to retrofit, most work remains quite siloed. Energy efficiency and heating installations are largely in separate supply chains, and the building physics knowledge to carry out an overheating risk assessment is even less likely to sit with the same project team. Overheating is also very poorly captured by the building regulations and planning process.
A holistic approach
The last few years has seen a growing awareness of overheating risk and an emergence of increasingly easy to use assessment tools. A very small fraction of UK homes have comfort cooling. Retrofitting a comfort cooling solution typically requires costly and complex changes to distribution systems. However, there are a range of low cost options, including using local extract fans to create interzonal air movement, or using night purges and thermal mass. Blinds are also incredibly useful, but often misused in summer, and can also help reduce heat loss in winter. There are also ways to use local microclimate features such as shaded areas or the North side of the building to bring in slightly cooler air from outside and reduce peak temperatures.
Improving the air tightness and fabric performance of our buildings to address heating in the winter will change how we implement these solutions for the summer. They require not only careful thought at the design stage, but also strong communication to help end users operate them properly. Simply opening a window is unlikely to help if the outside air is warmer than inside.
A significant problem is that there are insufficient drivers to force this type of holistic approach to design, performance, and communication. It is so often said that we need stronger policies in the area of heat and retrofit, and this is no doubt true. But while we await these policies it is incumbent upon each of us in this sector to share and collaborate as widely as possible, and use whatever influence we have over a given project to encourage a fair and forward looking solution.
In summary, the availability of cheap gas has allowed us to escape having to understand our buildings in much detail. Climate change is the catalyst for an untold level of change in our lives that we are going to start to truly experience in the coming decade. Heating and overheating are coupled issues that must be solved together. We must use the end of gas as an opportunity to understand our buildings better, and implement solutions to climate change that work across seasons, or we risk trading one problem for another.
In summary, the availability of cheap gas has allowed us to escape having to understand our buildings in much detail.
This is a BSRIA Member contribution to the BSRIA Blog, by Roy Jones, Technical Director at Gilberts (Blackpool) Ltd
Bars, restaurants and leisure venues are opening, schools have welcomed back pupils, people are heading back into work. But what, in the building services/ventilation sector, will be our new normal? One thing is already clear, things are going to change.
New Building Regulations
We have Building Regulations revisions imminent that will change the way we design ventilation strategies. The ingress of external pollutants should be minimised. Ductwork should be rigid, not flexible, and lengths kept to a minimum. Approved Document Part F is looking for not just a commissioning report to show the system works adequately, but information in operation and maintenance. The interim uplift for Approved Document Part L is looking for a 27% reduction in carbon emissions per building against the existing standard(1).
Inevitably, protecting against COVID, even despite the vaccination programme, will figure in specifiers’ minds. With the best will in the world, the initial Government guidance to achieve adequate ventilation re COVID of “opening windows” is not practical nor realistic as a long-term strategy alongside the global drive to cut carbon emissions and improve indoor air quality.
System evolution
Whereas on the face of it, the industry is facing a huge amount of change, the wherewithal to deliver is already widely available and in use. Legislation is just confirming what the quality manufacturers and engineers already implement. It all combines to, I believe, an increasing use of stand-alone ventilation and heat recovery systems, especially those that minimise energy usage. The latest evolution has been a hybrid- dynamic optimisation of natural ventilation, fan boosted mechanically when required. Ahead of the changes to Building Regulations, stand-alone versions have already been developed. Are these the way forward, to meet our requirements?
Some hybrid systems, such as units designed to meet current Regulatory guidance (eg. BB101 for schools), are stand-alone single-zone items, which obviates the need for ductwork, either to external or internal areas. No internal penetrations are required either, to move the air through the building, as each unit serves a dedicated zone, whether façade- or ceiling-mounted. This reduces major cost and labour in ductwork, fire dampers and silencers. The principle therefore already overcomes the potential obstacles when the revised Approved Document F comes into force. They ventilate just the one space, preventing transfer of particulates from one zone to another, and thereby minimising risk of internal cross-contamination. Some already deliver flow rates compliant with latest COVID guidance (i.e. to achieve a notional CO2 below 1000ppm). Carbon dioxide (CO2) is currently the metric used to check the air is ‘fresh’ within a zone. Links have been established that higher CO2 levels reflect higher Covid-19 risk.
Modular design
Within modular design products can be provided alongside a “mix and match” option of additions. These can be added to meet the specific use and requirements of the buildings to be ventilated.
Some options include:
filter modules to address fine airborne particles, and maintain the IAQ within required limits
connection modules to address site-specific installation limitations, to allow single-sided operation
heating coils that can remove the need for ancillary supplementary heating such as radiators,
acoustic attenuation to modulate noise below 30dBA
control unit to enable easy management of the IAQ and temperature to facilitate any over-ride as required. This provides capable boost and purge ventilation and night-time cooling.
Get it right
The amount of change, not just in Regulations, but how we use our non-domestic buildings in future, is vast. Specifiers and designers should use the expertise of product manufacturers to their advantage. It is wise to tap this knowledge bank to ensure delivery of the best compliant solution for the project.
BSRIA has released its latest global heat pump market reports, including the eagerly awaited report on the status of the UK heat pump market.
Last spring, deep uncertainty set in across the markets as lockdowns in many countries disrupted trading. There was fear within the heat pump industry of a significant slowdown in what had previously shown dynamic market growth.
Indeed, the global heat pump market posted a decrease of 1.5% in 2020. However, performance varied across regions: with 12% market growth year-on-year, Europe has been at the forefront; the UK also saw positive development with heat pump sales increasing by 9.2% in 2020.
Green Homes Grant
UK heat pump market sales were helped by the RHI and the Green Homes Grant scheme in 2020. The latter has proven to be important for the market, which has seen sustained growth in the refurbishment segment despite the number of installations in new buildings stalling due to the lower level of new home completions.
However, heat pump installation still represents a major challenge in existing homes. The ongoing review of Part L and Part F of building regulations offer hope that refurbishments in homes and buildings will be conceived with low carbon heating in mind, but the review’s outcomes are yet to become a legal requirement.
Moreover, even though there is market potential for a higher number of heat pump installations in existing homes, the government has, so far, been unable to unlock it. The Saturday 27th March announcement of the closing of the Green Home Grant scheme to new applicants by 31st March 2021 has been yet another example of the disappointing approach to deployment of energy efficiency measures and heat pumps.
UK heat pump market: Achieving a net zero carbon economy
Heat pumps are among the technologies the government has identified as key to achieving a net zero carbon economy by 2050. The Prime Minister’s 10 Point Plan for the UK Green Industrial Revolution includes the target to deploy 600,000 heat pumps a year by 2028.
The UK saw around 37,000 heat pumps sold in 2020. The extra £300 million in funding, moved from the soon-to-be defunct Green Homes Grant to local authorities to enable energy efficiency upgrades for lower income households, may bring additional installations. But even if all 30,000 applicable homes were fitted with heat pumps, the numbers are insufficient to sustain hope of reaching the PM’s ambitious target.. There is potential for more heat pump installations in existing homes, and the interest in heat pumps is growing among home and building owners. The heat pump industry is also working at full speed to deliver innovative products that respond to end-user expectations and environmental challenges.
HVAC industry skills gap
However, unless demand from existing homes and buildings is unlocked at full scale, and until real attention is paid to the sufficient availability of a skilled workforce, the heat pump market will struggle to see the acceleration needed to reach the government target and make a difference in the level of carbon emissions from UK homes and buildings.
Coherent policy and financial support are needed to match the readiness to act on both industry and consumer sides. Integration of heat pumps in a home or a commercial building requires a holistic approach where design and affordability should be considered to deliver carbon savings, cost savings and a healthy and comfortable environment.
The inauguration of the new President-elect, Joe Biden, marks the start of a period that could bring a substantial shift in US building-related markets. Air conditioning, heating, ventilation and controls are likely to face requirements from policy and market demand that will change dynamics in several segments.
Net Zero Emissions
With the President-elect’s Clean Energy Revolution announced during the campaign, the federal green agenda is set to make a strong comeback. President Biden signalled his intention to re-join the Paris Agreement, notably on the first day of his presidency, and outlined a national goal of net-zero emissions across the economy by 2050. Although less ambitious than the progressive Green New Deal target (net-zero emissions by 2030), with Congress now on his side he can venture putting his intention into law.
The President has promised a nearly USD 2 trillion investment plan, much of which is due to support green initiatives. He also promised to work towards achieving decarbonised electricity by 2035. Although during the campaign he was careful not to promote the ban of gas and oil fracking, his Clean Energy Revolution includes plans to improve energy efficiency in buildings and houses, and promises high investment in R&D related to zero carbon technologies to produce cutting-edge equipment for internal markets and export.
Even if not all of it might come to fruition, there is certainly a significant change of direction ahead in all industry sectors, including energy and HVAC in buildings.
HVAC Industry
During the Trump presidency, the federal government kept progress in energy efficiency standards for appliances and equipment at a low level. This has been countered by initiatives in several states, like California, Vermont, Washington, Colorado Texas and Hawaii, which have been setting their own efficiency standards for a variety of products. Federal standards nevertheless cover a wide range of HVAC products. Hence, the re-activation of ambitious federal efficiency programs will be important for industry and consumers.
California will likely increase its influence on federal decision making, not only as Kamala Harris’ home state, but because of its leading set of environmental regulations and standards. Its Title 24 Building Standards Code that sets requirements for “energy conservation, green design, construction and maintenance, fire and life safety, and accessibility” that apply to the “structural, mechanical, electrical, and plumbing systems” in buildings might provide a template for wider adoption. The experience the state is gathering on the application of a variety of solar and heat pump combinations can support the uptake of these technologies on a larger scale.
Green Agenda
With the push towards energy efficiency in buildings, technologies that support their smart operation are likely to see dynamic uptake. Currently, smart buildings represent a niche market across the US, with just some cities in the North-East, Texas or California seeing their increased emergence. They usually belong to corporations who are keen to emphasise their green credentials, aspiring to achieve high sustainability certificates through building sustainability assessments like LEED or WELL.
The impact of the federal policy change on the building HVAC and controls market will not be instant, but waiting for it to become obvious might have serious consequences for market players. The unfolding of the green agenda by the federal government will strengthen ongoing efforts of market stakeholders and demand from consumers as environmental awareness creates favourable conditions for the shift towards efficient, environmentally friendly products.
Socrates Christidis BSRIA Research Manager – Heating and Renewables
District Heating and Cooling networks have witnessed significant growth in many European countries in the last five years and this is set to continue in the coming decade. Significant European policy initiatives, such as the Green Deal, country government promotions, alongside increased public and private investment are supporting new business models such as utilities selling heat as a service and not as a commodity, which will drive the market forward.
BSRIA research indicates that the share of heat pumps and Energy-from-Waste in district heating and cooling systems is increasing. This trend is in line with the development of the concept of 5th generation heat networks. These are demand driven and low-temperature networks, using locally available low-grade waste heat (A/C, datacentres, underground stations, etc.), low temperature renewable energy in bodies of water and solar energy instead of a central energy centre. In principle, such systems favour the use of substations at building level, but no heat interface units at the dwelling level, as these are likely to be replaced by heat pumps.
Currently industrial boilers and CHPs remain the main source of heating in District Heating networks. For instance, 85% of planned heat networks in the UK, will have a CHP as the primary source of heating and 50% will have a gas boiler as a backup. The remaining 15% will use geothermal, ground source or water source heat pumps.
Thus, in the short-term Heat Interface Units (HIUs) will remain the link between the apartment and the network.
Going forward, reducing demand for heating and increasing need for hot water and cooling imply that the market will see the uptake of:
All-in-one units (heating or cooling and hot water)
Cooling units
Hybrid units, with integrated electric water heating
The main threats for HIUs market progress are the currently lack of consistent quality of installation and COVID-19.
Heat interface units have a major impact on the overall performance of a heat network and successful operation and performance both depend on correct system design and specification, followed by competent installation and maintenance. This has been problematic, with systems inadequately designed and quite often oversized. We see some signs of improvements as the industry becomes more sensitised towards good quality district heating. Documentation is improving as well as codes of practice, testing of HIUs, and further testing on site; however, under tight budgets the emphasis is often for the lowest cost, specification compliant technology. Testing the unit in a lab and then onsite is optional but critical to ensure performance.
Closing of construction sites was the main impact of the Coronavirus pandemic, including lack of cash flow, as the invoicing is done when products are delivered onsite. The industry has also witnessed a lack of new orders from April to June, with some signs of recovery observed just after. Overall, the European sales in the first 6 months of 2020 were between 15% and 30% down, depending on country, when compared to the 6 first months of 2019.
Going forwards, new construction presents a slightly positive picture. During COVID-19 there has been delays but not cancellations in planning permissions; delays as sites operate under social distancing guidelines and some delays for new investment to come through. However, governments and authorities are still eager to go ahead with programs and incentives, with renewed emphasis on the environmental agenda.
Looking at estimations for completions of flats before and after the outbreak, the recovery is likely to accelerate in 2022, and the market is unlikely to recover before. The end of financial support schemes by governments (VAT deferral, loan schemes or furlough) is likely to have a negative impact on many businesses, including contractors. Indications are, that new build and residential sales will be hit harder than commercial ones. Southern Europe is also likely to struggle more, although recession is expected across most of European countries.
Taking all this into account, BSRIA sees the numbers of heat interface units growing steadily but at a single digit compound annual growth rate of just over 4% on a Pan-European basis. The market will become more diverse and will look for more flexible options to cater for high-end, electricity-only heating, mixed-used and communal areas.
To find out more about BSRIA’s District Energy and Heat Interface unit market studies contact us at:
There is no denying global events this year have turned every aspect of our lives upside down, and as we all start to try and get back to normal while lockdown restrictions ease, we realise it is a “new normal”.
Workplaces have changed, some almost unrecognisable from before, and there is a myriad of requirements to consider beyond the essential health and safety measures. Occupant wellbeing was a prominent consideration prior to lockdown, and this included provision of a good acoustic environment, but how are new COVID-secure workplaces affecting the acoustic environment?
For many years there have been acoustic standards and guidelines on internal noise levels in offices, determining sound power levels of building plant, and predicting the sound absorption of materials. Well designed open-plan offices have allowed large groups of people to collaborate and communicate effectively, and noise regulations have ensured factories and construction sites operate without disturbing neighbours.
In recent months, the workplace has been turned on its head. Following government guidelines many people began working from home. Suddenly the familiar hum of the workplace was replaced in some instances with squabbling children or impatient pets, and if you live alone maybe unwelcome silence replaced your usual face-to-face conversations.
As people are gradually allowed to return to a place of work, new COVID-secure offices have changed the acoustic environment. The installation of screens, the partitioning of open plan spaces, wearing of face coverings, and a lower level of occupancy have created acoustic challenges. For example, speech intelligibility is affected by the reverberation time of a space. Fewer people and more reflective materials, such as plastic screens, will decrease the sound absorption and increase the reverberation time, resulting in poorer speech intelligibility.
Building services have been specified, installed, and commissioned for a particular set up of a workplace layout and building occupancy. If a space is divided into individual offices to allow for social distancing, then the building services provision also needs to be reconsidered. Changing the control settings of a system will have an impact on the internal noise levels and subsequently on levels of occupant annoyance.
Not everyone works in an office, so, what about situation in different workplaces? Factories, shops, and construction sites have been redesigned to allow for social distancing, and often operating hours have been extended to allow for shift patterns, potentially increasing noise nuisance for neighbours.
In these environments the noise levels are also often higher and communication between people can therefore be harder. People working further away from each other and wearing face coverings will inhibit successful communication and influence performance, and if someone must shout to be heard does this have the potential to spread virus droplets further? There should also be consideration of the highly overlooked 12 million people in the UK who suffer from some level of hearing loss. Being unable to lip read because someone is wearing a face covering, or unable to hear the conversation over a bad video conferencing link is incredibly frustrating and isolating.
The acoustic challenges within a COVID-secure workplace may seem overwhelming but there are several simple solutions. Firstly, identify noise sources in the workplace and maintain them appropriately to minimise background noise.
Something as simple as cleaning filters inside a fan coil unit can increase airflow and capacity, meaning the fan speed can be reduced and subsequently the noise level.
Secondly, examine acoustic specifications of any new products being installed – ask to see test reports and consider how a new product could influence the acoustic environment.
Finally, consider the occupants of your workplace and how they use the space. Tailoring the acoustic environment to the needs of the occupants can increase productivity, decrease annoyance and overall improve the wellbeing of all. The focus on workplace safety is paramount, but long-term considering other design parameters, such as the acoustic environment, will ensure workplaces not only survive but thrive.
BSRIA acoustic experts publish guidance, and support our members and clients with a range of acoustic testing solutions. Read more about our UKAS-accredited laboratory for acoustic testing to BS EN ISO 3741, BS EN 12102 and BS EN ISO 354 here.
A study from the UCL(1) revealed that building failures may cost the UK construction industry £1bn to £2bn every year. This was a conservative estimate made in 2016, based on 1 to 2% of the total value of construction.
As of March 2020, the Office for National Statistics has estimated the total value of all UK construction works to be worth £12.7bn, 68% of which is for new buildings or the repair and maintenance of existing buildings. This would give an estimated cost of failure between £85m and £170m, of which building services would account for a high proportion.
(1) Razak, D S A, Mills, G and Roberts, A (2016) External Failure Cost in Construction Supply Chains. In: P W Chan and C J Neilson (Eds.)
Types of failures in building services
Bathtub curve
The typical pattern of failure arising against time is shown by the well-known bathtub curve. The curve is divided into three segments: an infant mortality period, usually marked by a rapidly decreasing failure rate; a random failure period, where the failure rate continues at a
The first period is usually detected during the defects liability period after a project is handed over.
The second period would happen during the operation of a system, and failures may occur due to inappropriate operating conditions or maintenance regimes.
The third period is when the system is reaching the end of its life. Failure could be imminent and there should be little or no surprise in this happening.
Importance of investigating these failures
There is cost in everything: Always investigate to prevent repetitive failures
There are various reasons why every unexpected failure should be investigated. Below are some of the key ones:
Insurance purposes. Insurers may require an independent evaluation of the failure and investigation of its possible cause to identify possible fraudulent or malicious intentions.
Cost savings. Too often, failed components are replaced without investigating the root cause. Without understanding the origin of a failure, it is not possible to prevent its re-occurrence. Repetitive failure and replacement of components could add significantly to the operating cost for a building or estate.
Health and safety. In May 2009, a lift at London’s Tower Bridge tourist attraction suffered a vital mechanism failure that sent it falling with 9 people in it, four of whom suffered bone fractures. The malfunction was caused by the failure of a counterweight mechanism. The accident investigation by the HSE revealed that there had been several previous component failures with the counterweight mechanism, and the components had been replaced without proper review, and with no investigation into why they were failing so early. Tower Bridge was ordered to pay a total cost of £100k, and the HSE concluded that, had there been a proper review into the counterweight mechanisms, the catastrophic failure of the lift could have been avoided.
BSRIA can help with building servicesinvestigations
BSRIA has been in the building services industry for over 60 years and has been involved in hundreds of investigations.
Our independence makes us the ideal partner to provide non-biased failure investigations. Our expertise and capability in testing various materials and components of building services to determine the likely cause of failure is unique. We are able to perform investigations on site, examinations in our labs and analysis in our offices.
Our professional approach is such that there is no failure too large or too small to investigate today because this can save lives and costs tomorrow.
Read more about BSRIA’s Failure Investigation service here
Author: Martin Ronceray, BSRIA Engineering Investigation Lead
We are living in unprecedented times; The UK has never experienced such restrictions in peace time, and the world has never seen such wide-ranging restrictions in so many countries simultaneously. As we move deeper into the lockdown of the UK, our ability to effect essential maintenance activities is being adversely impacted. There are reports of specialist subcontractors being unable to attend sites, TFM providers having limited resources and members of in-house teams being unable to attend work due to self-isolation, sickness or concerns over the coronavirus.
Businesses are suffering from depleted competent resources and are also having to risk-assess the impacts to their remaining staff as part of exercising their own corporate duty of care. There are a lot of unknown facets to this issue as, by its name, the novel coronavirus is new. We can only work with the current guidance available and early indications of initial research that is being conducted.
BSRIA is recognised as experts in the field of maintenance, FM and the built environment and well known for our guidance on risk-based business-focused maintenance (BFM). Thus, we have been contacted by our members and clients for advice and support during this unique period. The advice we are offering is on interpretations of the government guidance as it applies to our industry.
The UK government has stated that “Making buildings safe … remains a priority for the government.” Whilst it is focused on public sector, the Crown Commercial Service is more maintenance-focused and has issued guidance on what to do if you are reviewing the need for a full or partial shutdown of buildings and a reduction in services.
The Health and Safety Executive (HSE), which enforces several pieces of legislation that contain time-bound statutory inspections, initially communicated that there would be no change to their outlook on missing these inspections. However, latterly the HSE have allowed for some pragmatism. There is no relaxation whatsoever on the duty-holder’s legal responsibility to maintain work equipment, but there is more acknowledgment of the difficulties of carrying out thorough examinations, written schemes of examination and statutory inspections. The document detailing this can be found here and the press release here. If maintenance intervention dates are exceeded and the choice is made to keep a certain asset or system running, documenting the risk and the actions taken to avoid this risk is very important. The HSE provide some useful guidance on this here.
BFM respects statutory and mandatory requirements but has long advocated a review of non-statutory generic time-based interventions. Indeed, BSRIA’s BFM practitioners travel to sites up and down the country and across the globe, supporting building owners and operators with independent, authoritative advice on how to maximise business-function-critical building service uptime, whilst minimising cost and time resource investment. Targeted use of condition monitoring can often provide more uptime than intrusive maintenance permits and avoids the risk of maintenance induced failures.
When buildings are left unattended, certain considerations need to be made. If a building is vacant, then it should be mothballed, or put in an appropriate state of stasis. The BESA produced guidance on this in 2006 and published it under the title SFG 30. If there is even a skeleton staff in the building, then systems will need to be kept running.
Water is one of the first things to consider. Whereas under normal operations there may have been a handful of little-used outlets, in reduced operation stage, the vast majority of the outlets are possibly going to be termed as little-used.
As it is much easier to maintain a water system in a wholesome condition than to try to rid it of proliferated biology, it is recommended to ensure the flushing is attended to. We have an article on the subject here, but the basics are: keep cold water cold, keep hot water hot and keep both moving. That advice works for the pumps too. For buildings that are still operating, cooling systems should be kept running regularly or as needed based on sensor inputs.
There is a growing body of investigations that is suggesting an indoor condition of 24°C+ and ≈50%rH+ is helpful in controlling SARS-CoV-2. However, the Federation of European Heating, Ventilation and Air Conditioning Associations (REHVA) has produced documentation that does not support this and suggests that the figures are closer to 30°C+ and ≈80%rH+ which would not be convenient in a building. If the building is being (or has been) vacated and will remain unoccupied for some time, then cooling towers can be drained and local authorities notified.
Heating is the same, we should keep things running at regular intervals or as and when there is a requirement for a heating load. It is the time of the year when we would be considering shutting down our heating systems, and those activities could be pulled forward, ensuring inhibitors topped up to keep the pipe condition and biological content within desired parameters.
Regarding ventilation; there is much discussion about the transmission methods of coronavirus. Is it fomite and droplet only, or is it airborne? There is talk about UV treatment of ventilation, HEPA room cleaners and whether, in the near future, these sorts of technologies will become the norm.
Based on the latest information and advice on the subject, it is possible to identify a unifying golden thread that puts emphasis on keeping the fresh or outdoor air coming in. Increasing ventilation appears to be the best solution. Creating negative pressures in the toilet areas and filling all other areas with as much fresh, non-recirculated air as possible and similarly increasing extract volumes is repeatedly stated as the best practice for ventilation systems. This may entail manual intervention to fully open dampers, close recirculation paths (including heat recovery where air streams mix), and considering running close to maximum air flow rate for up to 24 hours a day 7 days a week for any level of occupancy in a building.
Life safety systems will need to continue to be looked at even if buildings are at a low occupancy. BSRIA can give guidance on where to go for the best advice on any of these systems. If buildings are being mothballed, one consideration that will need to be made is contacting insurers to understand their coverage requirements. Systems that fall into the LOLER or PSSR categories will have their own considerations as governed by the HSE. Emergency lighting checks in an unoccupied building can be halted and then conducted prior to re-occupation. In an occupied building, the advice changes.
Due to the level of enquiries we have been fielding from our members and clients BSRIA have hosted discussion on this subject to gather industry input and opinions. It is possible to hear this presentation here.
I will finish by reassuring you that you are not alone in this. We are here to support you though these strange times and welcome your calls and emails about how we can support you.
Be safe.
PS: If you are not familiar with BFM, we have an article on the subject here and we would be more than happy to take enquiries on our consultancy@bsria.co.uk email address, but in a nutshell it is a way of adapting PPM routines to focus on the business’s main activities and ensuring that the installed building services are able to support them.
BSRIA first published guidance on BFM in 2004, and the current guide, BG 53, was published in 2016.
Buildings account for approximately 40% of the total energy we use. Based on this statistic, even a small improvement in energy efficiency in our buildings could have a huge impact on the environment.
A reduction in the amount of heat that escapes through a building envelope is one of the most important aspects of energy-efficient building design. Keeping the heat within the confines of the conditioned area removes the necessity to supply more energy to the space.
On the flip side, the problem of overheating suggests that heat, and energy production, within a lightweight structure needs to be carefully managed for fear of increasing the internal temperatures to uncomfortable and sometimes dangerous levels. It is implied that the cost of cooling a space far exceeds the equivalent cost to heat a space.
In an effort to keep the heat inside the building, a strategy to ensure attention to the airtightness and insulation detail throughout the construction process should be incorporated at the design stage. Consequently, to ensure that any negative effects associated with possible overheating and moisture ingress due to such an airtight structure are kept to a minimum, the construction must be designed with an appropriate ventilation strategy.
Challenges of different construction methodology
Construction methods face individual challenges when considering the design of an energy-efficient example of its product.
The design and construction of volumetric modules, for example, have huge efficiency benefits when considering the increased production and uniformity of manufacturing on an assembly line. However, the transport of each module and the assembly of multiple modules on-site can introduce areas of weakness in the overall building fabric that would not be apparent in the factory.
When considering a timber frame, the junctions between frame elements can be subject to unexpected stresses and movement as the natural timbers settle into their new environment. These movements, no matter how small, can introduce significant air leakage paths into the building fabric and therefore have a negative contribution to the thermal performance of the finished building.
In both above examples, rigorous quality testing should be performed to ensure the quality of the finished building, proofing that it has been built and assembled to the designed specification.
Image: iRed
Airtightness Testing verifies the quality of building fabric
Airtightness testing demonstrates the ability of a building to hold air. The test generally involves using a fan to measure how much air needs to be blown into a building to achieve a certain pressure; a building with a more airtight building fabric will require less air through the fan. The value of the result, which is referred to as the permeability of the building fabric, is required by Building Regulations to have a maximum value of 10 m3h-1m2, although most buildings are specified at a lower level at the design stage to achieve a lower EPC (Energy Performance Certificate). The government stipulates that all new buildings must be airtightness tested before handover to ensure quality control.
Airtightness testing is a very good way to verify the quality of the building fabric. However, it can only quantify how much air is coming through your building fabric and does not inform where the air leakage paths are. In contrast, thermal imaging can tell you where the air is leaking but it cannot quantify how bad the air leakage is. Performing both is therefore providing full set of information that is needed to ensure that the designed specification is achieved.
Image: iRed
How Thermal Imaging can lead to improvements in energy efficiency
Thermal imaging process of the building fabric implies the use of a thermal imaging camera to observe and assess the thermal performance of building fabric elements. It allows us to ‘see’ the effects of the heat generated by items around us, and to ‘see’ the areas of the fabric that have the lowest thermal performance.
When used to survey the building fabric, the camera shows temperature variations on the surfaces of the construction elements that suggest locations of air leakage, areas of thermal bridging and locations where the insulation continuity is broken. Each of these issues will have a detrimental effect on the thermal performance of the building. The anomalies found during the process often represent an area of the building that has not been built to specification. Highlighting them allows the rectification and subsequent improvement works to take place before they become a problem to the occupier.
The use of airtightness testing and thermal imaging is a relatively quick and cost-effective way to verify the performance of the building fabric of the finished building, be it an assembly of volumetric modules or a “completed and wrapped” timber frame.
Any thermal anomalies found during these surveys can be rectified before the building is occupied. If no anomalies are found, then the building has documented proof that it has been built to the specified standard. This should mitigate overall disruption and ensure occupier’s satisfaction.
The information collected during the survey can be fed back into the design process and further improvements can be made in future iterations of the product. In this way, these diagnostic tools can be used not only to maximise the energy efficiency of the current building but can also be used to improve the design and construction process of future projects.
Joe Mazzon Research Engineer BSRIA
For more information on Thermal imaging and Airtightness testing please contact: thermography@bsria.co.uk or call 01344 465578
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