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While the eyes of the world were focused on Glasgow and the United Nations’ COP26 event, the building services industry was gathering online to consider its own priorities for tackling the climate crisis.
The two days of the Building Engineering Services Association (BESA) National Conference took place during COP26 and focused heavily on how our industry could put a dent into the 40% of total global emissions that come from the built environment.
BESA’s opening keynote speaker, the TV personality and architect George Clarke, issued a passionate plea for a “global retrofit revolution” that would fundamentally shift the performance of existing buildings. He called for VAT to be scrapped on restoration and renovation projects to encourage a more sustainable approach – one focused on reusing existing structures and making them more energy efficient to tackle both embodied and operational carbon.
However, when Professor Cath Noakes took to the virtual stage on day two of the conference, she stressed the need for the net zero agenda to pay close attention to the impact buildings have on the health, well-being, and productivity of people – and the importance of not sacrificing the human experience when looking at ways of cutting carbon.
She told the Conference that the pandemic had exposed systemic failings in how we design and retrofit buildings.
Excuse
“Many of our buildings are under-ventilated and there is no excuse for it,” said Noakes, who is Professor of Environmental Engineering for Buildings at the University of Leeds and a member of the government’s SAGE advisory group.
“This is not just about complying with regulations. We know buildings improve health and that poor indoor air quality reduces productivity by up to 9% - that’s half a day a week,” she added, pointing out that before the pandemic 5.3 million working days were being lost every year to respiratory infections, according to the Office for National Statistics (ONS).
“But that is still not as tangible as your energy bill, so we need to push [the health] message harder,” she told the BESA Conference.
She also called for stricter professional accreditation for ventilation professionals similar to the health & safety scrutiny experienced by workers in the gas and electricity sectors, for example. Improving standards will be vital to ensure ventilation systems are designed, installed, and commissioned properly – and are monitored in use to determine whether they are delivering the health and well-being benefits needed.
“The increased amount of indoor air quality monitoring since the pandemic is helping because it is making people more aware of their indoor environment,” said Professor Noakes. “However, it is now clear that it is very hard to naturally ventilate buildings adequately in winter – that needs to be looked at urgently.”
This clearly points to far greater amounts of mechanical ventilation being required to address the huge number of buildings suffering from poor indoor air quality (IAQ). The pandemic has created an impetus for change that is long overdue.
Public Health England estimates the annual death toll in the UK from air pollution at between 24,000 and 36,000 with associated healthcare costs as high as £20bn. Most British people spend more than 90% of their time indoors so the influence of inside spaces on these shocking figures cannot be underestimated and goes to the heart of the UK’s struggles (specifically the NHS) to cope with a spiralling health crisis.
Also, our response to the ventilation challenge must go much further than simply addressing the immediate challenge posed by the risk of an upsurge in Covid-19 infections. We must provide affordable, long-term solutions that protect building occupants and safeguard wider health and well-being.
Another speaker at the BESA Conference, Ella Clark of AECOM, warned that achieving that critical balance between our carbon cutting obligations and higher levels of ventilation would be hard.
“We know that doubling the rate of ventilation reduces the spread of Covid-19 by around half and that the World Health Organisation (WHO) recommends ventilation as the first-line strategy for getting people back to the office,” she said, but added that every additional 0.28l/s per person can increase energy consumption by 0.6kWh/m2 per year for an office building.
She said that mechanical ventilation offered a more controllable approach that also uses filtration to reduce the ingress of pollutants into buildings to protect occupants from other potential risks to health, but there were cost implications including the need for the systems to be cleaned and maintained; and the running costs associated with higher pressure drops across filters.
Humidity
She also raised the importance of humidity control saying that the average relative humidity (RH) in UK offices was 38% which can cause physical problems such as eye irritation, and dryness of nose and throat. At 23% humidity, 70% of flu particles can cause infection an hour after they are introduced to the air, but at 43% humidity that drops to 14%.
The solution is to measure what is happening in the occupied space and then use demand-control to create a healthy indoor climate with the lowest possible energy consumption – and the best lifecycle return.
Doug Booker, CEO on National Air Quality Testing Services (NAQTS), told the BESA Conference that the retrofit revolution proposed by George Clarke would need to be powered by performance data. “You can’t improve what you can’t measure,” he said.
The secret is being able to visualise the problem i.e. make the invisible visible by using digital systems to accurately map the level of contaminants in the air that need diluting and the volume and direction of airflows in the space that will protect human occupants from the risk of disease transmission and exposure to sources of respiratory infection.
By making all the crucial factors, including humidity control, available ‘on demand’ you can minimise the amount of energy needed to achieve the ideal conditions. Rather than simply ramping up the ventilation – a hammer to crack a nut – you target your response and make it more effective AND sustainable.
With COP26 delegates tying themselves in knots over the wording of complex agreements, our industry can certainly play its part by proposing and developing relatively straightforward solutions, like demand-controlled ventilation, that go right to the heart of the matter and contribute to a general improvement to indoor environmental quality (IEQ) without the carbon penalty.
The Swegon WISE system is a practical application of this approach as it can already adjust the indoor climate to deliver what the building needs at any given moment by optimising airflows. A newly added water optimization feature uses data input from each room that is used to control the heating and cooling system, resulting in a further decrease in energy consumption of up to 15%.
That is real progress, but we also need to get to the next level, beyond optimized products. We need to collect information from outside the system, such as weather predictions and up to the minute costs of electricity. By combining this information with data from the products we can create smarter buildings and develop smarter products that find the critical balance between energy use and the health, well-being and productivity of people.
