Introduction
We continue our focus on ventilation by turning our attention to the healthcare sector and specific considerations for building designers, facilities managers and other stakeholders when designing ventilation requirements for these facilities. Whilst the basic principle is the same across all sectors that good ventilation is vital to ensure the regulation of healthy air for breathing and removing pollutants, as well as helping reduce condensation and mould growth, the healthcare sector has some complex and specific requirements.
We are clear that ventilation is the process of providing outdoor (fresh) air to occupants within a building and removing stale air that may be contaminated. Ventilation is essential for a healthy indoor environment and is widely recognised as a key mechanism for controlling the transmission of airborne infections, vital to any healthcare setting.
Infection control and patient safety
Healthcare settings are particularly complex, sensitive and high-risk environments. On a daily basis they accommodate a high density and flow of users that differ in terms of their health status along with many different activities. Patients may be particularly susceptible to airborne infection risks, even at low concentrations, such as those with lung or heart conditions, who may have to visit and spend long periods of time in a clinical environment. Yet air quality in healthcare facilities can be a significant risk factor owing to the presence of pollutants such as volatile organic compounds (VOCs) from cleaning agents, biological contaminants such as airborne pathogens, and particulate matter, that are often at higher concentrations compared to other indoor spaces. Furthermore, the provision of a round-the-clock service by hospitals means there is no idle time to recover from emissions and the consequent impact on indoor air quality.
Sources of poor IAQ are the same within clinical environments as they are in other indoor environments, however, the high level of cleaning, disinfecting and sterilising required plus the high footfall can hinder air quality. Pathogenic microbes are also suspended in the air, enabling the disease to be transmitted through coughing, sneezing, and talking by infected patients, staff, and visitors, meaning the indoor air contains a complex mixture of chemical, particulate, and microbiological compounds. Staff, patients, and visitors are sources of microbial spreading and are also vulnerable to infection and as a consequence, cleanliness is of the utmost importance, with hygiene measures and infection control policies required to be stringently observed.
Healthcare facilities must also deal with polluted air coming in from the outside where emissions from road traffic, including hospital parking facilities, and generators employed to prevent power interruptions represent a further threat to IAQ.
Standards and Guidelines
Applicable to all building types, the Building Regulations Approved Document F outlines the requirements for ventilation in all buildings. The aim of the requirement is “to protect the health of occupants of the building by providing adequate ventilation. Without adequate ventilation, mould and internal air pollution might become hazardous to health.” It also states that ventilation may be delivered through natural ventilation, mechanical ventilation or a combination of both.
The Health Protection Surveillance Centre (HPSC) is Ireland’s specialist service for the surveillance of communicable diseases. It works in partnership with health service providers and other organisations in Ireland and around the world, to provide the best possible information for the control and prevention of infectious diseases. It offers a whole host of guidelines to support health care providers make the right choices for infection control and management to be considered in conjunction with design criteria.
HTM-03-01 (Healthcare Technical Memoranda) applies to healthcare facilities in the UK under NHS guidance, setting out the standard and expectation for ventilation equipment in healthcare applications. To comply with this memorandum to keep patients, staff and visitors etc safe, the ventilation system must comply with all the specifications outlined in HTM 03-01. The memorandum has two parts, Part A for Design and Validation and Part B for Maintenance.
The recommendations in HTM 03-01 lay out the minimum requirements for ventilation systems and also that there must be allowance for the safe access to these systems for inspection and maintenance purposes.
In the absence of other guidance, 10 L/s/person should be taken as the minimum ventilation requirement. Healthcare ventilation systems will normally be “full fresh air” either by natural, mixed mode or mechanical means, with energy recovery from the extracted air.
In non-clinical areas recirculated air systems may be considered. At least 20% of the recirculated air should be fresh. Additional filtration will be required to remove airborne particulate contamination and, if necessary, odours.
CIBSE Guide B provides guidance on the practical design of heating, ventilation and air conditioning systems.
Designers and stakeholders must also adhere to The Health and Safety at Work etc Act 1974 as the core legislation that applies to ventilation installations. As these installations are intended to prevent contamination, closely control the environment, dilute contaminants or contain hazards, their very presence indicates that potential risks to health have been identified.
With the nature of a complex healthcare facility, The Control of Substances Hazardous to Health (COSHH) Regulations 2002 must also be adhered to, which places an obligation on management to ensure that control measures are in place to protect staff and others affected by various work activity.
Workplace (Health, Safety and Welfare) Regulations are also key, which state that
- All enclosed workplaces must be ventilated by natural or artificial means.
- Any plant provided under this legislation must include an effective device to give an audible or visual warning of plant failure where necessary for health and safety.
- The Regulations require that ventilation systems are maintained in an efficient state, in efficient working order and in good repair.
Health Building Notes give “best practice” guidance on the design and planning of new healthcare buildings and on the adaptation/extension of existing facilities. They provide information to support the briefing and design processes for individual projects in the NHS building programme. All Health Building Notes should be read in conjunction with the relevant parts of the Health Technical Memorandum series.
Ventilation system will be subject to one visual annual inspection with critical healthcare ventilation systems inspected quarterly such as those in operating suites or critical care areas.
Design considerations
Natural ventilation should always be first choice, however the practicality of this alone in a healthcare setting is very limited and difficult to control. It is almost impossible to maintain consistent flow rates and ensure that minimum ventilation rates can be achieved. However, this variability is normally acceptable in non-clinical spaces such as office accommodation, staff areas, library/seminar rooms and some clinical areas and care spaces and waiting and consulting rooms where risk of airborne infections is likely to be low. Where it is essential to achieve a minimum ventilation rate at all times, mixed mode or mechanical methods will be required.
The health benefits of fresh filtered air in medical and healthcare settings are numerous. MVHR systems provide fresh, filtered air 24 hours a day, 7 days a week, minimising pollutants in the air. Such systems also control the moisture content of the air, reducing damp and mould which can have detrimental effects on health and wellbeing. Partel’s LUNOS Decentralised Ventilation Systems, are ideal for healthcare environments since systems are installed in individual spaces enabling local control and monitoring, all ensuring exceptional thermal comfort and excellent air quality. The LUNOS decentralised ventilation systems are ductless, compact, energy-efficient and quiet, as well as being easy to adjust and operate.

Hospitals and other care environments have a particularly high energy demand and hence the sector requires the utmost energy efficiency in the specification of ventilation systems. Energy reduction must not be done at the expense of patient, employee and visitor safety and comfort, however maintaining both indoor air quality and patients’ safety while reducing energy use is still achievable with the LUNOS Decentralised System range.
As discussed a decentralised system controls individual rooms/spaces and does not require the installation of ductwork as each room has its own ventilation system, whereas a centralised system controls the air quality in multiple spaces/rooms with a series of ductwork. The decision on which system is dependent on room complexity, building type and project requirements.
HEPA (High Efficiency Particulate Air) Filters are installed where the highest level of air filtration is required in applications such as operating theatres as well as in research facilities, electronics industries, nuclear and pharmaceutical industries. The filtration medium is provided by microfine glass fibres formed into a paper-like surface, supplied in various grades depending on the filtration efficiency required. We are starting to see research published around the impact of air filtration, specifically on certain microorganisms. A crossover study in two COVID surge units conducted at Cambridge Hospital introduced air sampling units and portable HEPA filters. When the portable HEPA filters were introduced, SARS-CoV-2 was eliminated from the air, and when the HEPA filters were removed, SARS-CoV-2 was once again detected in the air. More evidence is required to demonstrate the benefits of air filtration in reducing the risk of transmission of infectious microorganisms.
Future trends and innovations
Ideally, we require all healthcare facilities to be correctly ventilated for the best health and wellbeing of all occupants, however the level of activity varies in any given 24 hours, yet we tend to ventilate empty rooms as if they were occupied.
The most advanced system to counter this is DCV (Demand Controlled Ventilation), whereby a smart system adjusts/reprograms the ventilation settings within a building, based on fluctuating occupancy and can automatically reduce ventilation intensity during off-peak hours. This maximises comfort, minimises costs and reduces energy consumption by regulating temperature, air quality, humidity and occupancy.
According to CIBSE Guide B, mechanical ventilation with heat recovery (MVHR) systems can reduce energy consumption by up to 70% while ensuring proper air exchange rates for infection control.
UV-C light integration is also an emerging technology, which can be integrated into air handling units and ventilation systems. It is a know disinfectant which targets bacteria and viruses including airborne, waterborne and surface micro-organisms to improve IAQ. In critical applications, such as healthcare, UV-C can be used in combination with a HEPA filtration system to remove deactivated particles and other microscopic contaminants from the air.
In a world where we spend the majority of our time indoors, the quality of the air we breathe in our homes, workplaces, and schools is essential to our health, well-being, and productivity. It is even more vital in a healthcare environment where we have high traffic-flow from a range of occupants from staff and visitors to the patients themselves, who are likely at their most vulnerable in this environment.
Conclusion
The importance of investing in an effective ventilation system which will serve the many requirements within the hospital buildings is vital and the LUNOS decentralised systems can achieve this objective. Caring for the critically ill and minimising infection and cross-contamination through improved air quality is key to keeping patients and other users safe and ensuring an environment that promotes well-being and comfort.
WHO’s latest report in 2021 shows there is a much stronger body of evidence that air pollution affects different aspects of health even at lower concentrations than previously thought. The WHO report estimates that there are approximately 7 million premature deaths worldwide caused by the combined effects of exposure to both outdoor and indoor air pollution, with further millions falling ill from polluted air. This latest report has updated to more stringent air quality guidelines for particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide, with the guidelines now being applicable to both outdoor and indoor environments.
Although not mandatory, efforts from multiple disciplines involved are needed to address these challenging guidelines. Partel in partnership with LUNOS can support the healthcare sector in ensuring that these guidelines as well as the relevant standards are met to ensure the safety and comfort of healthcare users.
References
- https://www.hsj.co.uk/patient-safety/importance-of-indoor-air-quality-in-healthcare-settings/7033999.article
- https://www.england.nhs.uk/wp-content/uploads/2021/05/HTM0301-PartA-accessible-F6.pdf
- https://www.england.nhs.uk/wp-content/uploads/2021/05/HTM0301-PartB-accessible-F6.pdf
- https://www.bsria.com/uk/news/article/maximising_effective_ventilation_clean_air_must_be_a_right_not_a_chance_encounter/
- https://gamahealthcare.com/how-rediair-can-address-nhs-englands-new-air-filtration-guidelines/
- https://www.swegon.com/uk/knowledge-hub/technical-guides/we-explain-demand-controlled-ventilation/
- https://www.who.int/news-room/feature-stories/detail/what-are-the-who-air-quality-guidelines
- https://www.gov.ie/en/press-release/bde07-minister-for-health-publishes-the-national-clinical-guideline-no-30-infection-prevention-and-control/
- https://www.ashrae.org/technical-resources/standards-and-guidelines
- https://www.bsria.com/uk/
- https://www.england.nhs.uk/wp-content/uploads/2021/05/HBN_11-01_Final.pdf
- https://www.cibse.org/knowledge-research/knowledge-portal/guide-b2-ventilation-and-ductwork-2016/
- https://books.google.co.uk/books?hl=en&lr=&id=HID6NpLrwOsC&oi=fnd&pg=PR1&dq=ventilation+guidance+for+healthcare+facilities&ots=v_Ar8fBY5R&sig=2-j0bEbIq9lXRDX1kg5l19Wjdr4#v=onepage&q=ventilation%20guidance%20for%20healthcare%20facilities&f=false