Healthcare design has been thrown into the spotlight over the past year - from rapidly-built hospitals, both permanent and temporary, to adhoc mobile COVID-19 testing units.
At this very moment, architects and specifiers are carefully re-imagining the spaces in which essential, life-affecting services are delivered to offer greater efficiency and minimise cross contamination.
Of course, healthcare facilities need a constant flow of fresh, high-quality air. But, equally important, is the need for this air to be delivered in an eco-friendly way.
And, amid the ongoing holistic discussions around building design; air quality is one area which has come under scrutiny; particularly, its long- and short-term effects on patient, and staff, health and wellbeing.
The need for high quality air
Erik Boyter, chief executive of WindowMaster, told BBH: “It’s well established that good ventilation plays a key role in minimising the risk of aerosol transmission, with numerous studies finding that well-designed HVAC systems can contribute to minimising disease transmission and improving patient recovery.
“These buildings witness an influx of people on a daily basis, and poor air circulation will inevitably have a negative impact on their health.
“It’s particularly hazardous to resident patients who will suffer from long-term exposure.
“And, as such, maintaining a sterile environment with a low possibility of airborne germ transmission is critical.”
It’s not only patients at risk; poor ventilation also affects staff.
A Harvard study in April 2020 surveyed over 3,000 workers across 40 buildings and found a staggering 57% of total sick leave could be attributed back to poor indoor air quality (IAQ).
And this has significant implications for healthcare settings, where the risk of illness and contamination is considerably greater.
From an environmental perspective, smart passive ventilation reduces reliance on carbon-intensive mechanical ventilation systems, consequently reducing a building’s operational emissions
“Having effective ventilation systems prevents a host of other problems, from increased allergies, asthma issues and light-headedness, to headache and grogginess, called Sick Building Syndrome”, said Boyter.
“Depending on the source strength, and length, of exposure; risks include stress, anxiety and poor mental health, through to serious pulmonary and respiratory diseases.
“In short, bad air negatively affects everyone.”
It’s a serious issue, and one which demands a reassessment of current ventilation systems.
“This should be seen against the backdrop of COVID and the World Health Organization’s recent roadmap to improving indoor ventilation, but also the NHS’s commitment to becoming the world’s first Net Zero health system,” explains Boyter.
“Of course, healthcare facilities need a constant flow of fresh, high-quality air.
“But, equally important, is the need for this air to be delivered in an eco-friendly way.
This is a process of protecting people and the natural environment, too.
“It goes hand-in-hand, and is entirely achievable, as attitudes towards building design change.”
Fortunately, passive ventilation systems are capable of delivering on both requirements.
Essentially, passive ventilation is the process of supplying and removing air from a space, with minimal, or no, mechanical aid.
In basic terms, ‘fabric first’ is a building method by which you look to maximise a building’s thermal performance through the materials used in its construction
When appropriately designed and controlled, it harnesses the potential of natural elements, such as wind and thermal buoyancy, to regulate temperature and improve indoor air quality by bringing fresh air in, and sending stale air out.
This is largely achieved through the strategic opening and closing of a building’s windows and vents, which act as a source of air, as well as an exhaust.
“When properly programmed, using the latest sensor-backed smart controls, these systems deliver better-quality fresh air that flows through the building without compromising personal comfort,” explains Boyter.
“These controls automatically ensure each room is supplied with the appropriate amount of ventilation for a healthy indoor environment, keeping the temperature constant and at a pleasant level. It also removes the need for constant manual adjustment.”
A low-carbon investment
He adds: “From an environmental perspective, smart passive ventilation reduces reliance on carbon-intensive mechanical ventilation systems, consequently reducing a building’s operational emissions.
“This means less maintenance and significantly-lower utility bills.
“Buildings which take a hybrid approach, combining natural and mechanical ventilation to meet specific needs, also stand to reap the benefits of this blended model, which can prove to be even more efficient than a purely-natural solution.
“In line with the NHS’s drive towards Net Zero by 2040, it is hoped that passive ventilation systems will become a key part of the strategy, making them the norm in our built environment, as opposed to the exception.
“It’s another step along the way to halting climate change and simultaneously improving public health.”
The holistic approach
As effective as passive ventilation systems are, common practice advises they should not be used in isolation.
It’s up to the UK Government, working alongside the NHS, private providers, and built environment professionals to step up and develop a strategy to achieve a green transformation of our healthcare assets
They are best considered alongside other modern, eco-friendly design and building techniques, and are particularly effective when used in conjunction with a ‘fabric-first’ approach to design, says Boyter.
“In basic terms, ‘fabric first’ is a building method by which you look to maximise a building’s thermal performance through the materials used in its construction,” he adds.
“It exploits the potential of thermal gains, absorbing them into its structural mass throughout the day, and releasing accrued heat slowly by night.
“Passive ventilation complements this through night purging, pro-actively cooling the thermal mass prior to building occupation and reducing cooling bills.
“Smartly-controlled passive ventilation can make this process even more efficient and effective.
“If it’s programmed, and controlled according to fluctuating indoor and outdoor conditions, it works whatever the weather or climate, all year round.”
However, the journey towards universal passivity, not only in ventilation, but other areas of design; will be a gradual one.
“In addition to the scheduled new facilities being built, there’s also a substantial retrofit programme to be undertaken,” said Boyter.
“Fortunately, retrofitting passive ventilation is relatively-low impact, depending on the windows and vents already in place.
“Even where new windows are needed, the impact is low compared to installing a whole mechanical system.”
He adds: “This will need to be addressed soon, and it’s now up to the UK Government, working alongside the NHS, private providers, and built environment professionals to step up and develop a strategy to achieve a green transformation of our healthcare assets.
Not only will we see a marked improvement in public wellbeing, but also a happier, more-focused and more-productive sector workforce, as well as a more-sustainable healthcare system
“Of course, this all needs to be delivered while offering the highest levels of service and safety to staff and users alike.
“But, ultimately, there are real benefits which will be quickly registered and will make this process worthwhile.
“Not only will we see a marked improvement in public wellbeing, but also a happier, more-focused and more-productive sector workforce, as well as a more-sustainable healthcare system.”