A risk-based approach to HVAC replacement

“Ventilation is used extensively in all types of healthcare premises to provide a safe and comfortable environment for patients and staff and control odours”, according to Health Technical Memorandum 03-01, Part A.1 Whilst this is a basic description of the purposes of heating, ventilation, and air-conditioning (HVAC), it could equally apply to retail outlets and restaurants. In hospitals, however, we have additional requirements to reduce the risks of airborne infections in areas such as operating theatres and critical care units, but also the risk to staff of microorganisms and toxic substances.

‘Hidden services’ often overlooked

Within healthcare organisations there are significant cost pressures on capital budgets through the competing demands of estate maintenance, medical equipment, information technology services, and building modernisation programmes, let alone the HVAC equipment used in hospitals and other healthcare facilities. Hidden services such as estates plant are often overlooked, and seen as the poor relation, but are central to the provision of clinical services. Many organisations fall into this trap — where the estates plant provision is almost an afterthought, and specified and procured largely without clinical input. Changes in clinical practice, and advances in medical technology, make redundancy a further factor impacting on the lifespan of plant, but also changes in demands being placed upon it. There are a number of strategies that could be introduced in order to maximise the return on investment of our estates plant, one of which is structured rolling replacement planning. Communication of this issue to the Finance directors and Trust Boards is therefore critical to business continuity and energy management.

While at first glance ‘sweating’ our assets (estate plant) for a longer period of time appears to be an obvious and simple solution, it is not without risk; therefore, the question which must be posed is: ‘Is this a sensible solution? HTM 03-01 recommends a ‘working life of up to 20 years'(page 106),¹ but there are many HVAC systems still in use in hospitals that are more than double this age. There is a risk of ‘technical redundancy’ were either the plant no longer supported by the manufacturer, termed end of support [EoS], or where new technologies will offer significant benefits, improved accuracy, more efficiency, and better functionality. Direct-drive electronically commutated (EC) fans are now the preferred choice, and there are efficiency gains with energy recovery devices, but these come with their own risks, such as overheating and noise pollution.

Advancing clinical techniques

Clinical techniques are always advancing through research, and this can also lead to plant becoming no longer fit for purpose, i.e. a scenario of ‘clinical redundancy’. A good example here would be the need for an ultraclean (UCV) operating theatre for orthopaedic surgery. We must also consider the impact on services — for example failure of the plant may create patient safety risk, but also there are more strategic implications, such as a service continuity risk. An operating theatre out of use for one day can cost up to £70,000-£80,000 in lost revenue. Potentially there is also a financial risk through penalties of failure to give the services set out in a Service Level Agreement (SLA). It may therefore be prudent to replace equipment through a well-considered and risk-based strategic rolling replacement programme, rather than suffer the consequences of equipment failure.

Even before we start to look at a strategic replacement programme, we need to ensure that we have the necessary data from which to plan. Essential therefore is an accurate asset list of all HVAC systems. Having an up-to-date, well-informed dataset supports a much more robust argument, and enhances Estates Department credibility when approaching the director of Finance or the Capital Investment Committee for monies. While this might seem obvious, there are plenty of hospital Trusts with this basic information not at hand. Changes in the way records are held — with the switch from paper-based to electronic records, or, for example, changes between different software applications, may have led to some valuable historical information being lost. Therefore, even if an asset register is available, its accuracy should be verified. The HTM gives us guidance on compiling an asset register or inventory, and suggests the list is subdivided into four categories:

• Local exhaust ventilation (LEV) systems.
• Critical healthcare ventilation (CHV) systems.
• General ventilation systems (GVS), and General extract systems (GES)1 (page 141).

A unique identifier

Each system should be assigned a unique identification code or asset number. HTM 03-01 sets out a list of important information to capture about a system, but for strategic replacement planning, only a subset of this is required. Along with the identification code we need to know the purpose of the system, the equipment installed, the date of installation, and the area served. While the purpose of the system might seem obvious, hospitals are in a continuous state of reconfiguration, and clinical areas are frequently moved, which may impact on the requirements of the HVAC system. Furthermore, by removing any ‘ghost’ assets (those that no longer exist), a true picture can be painted of the asset base.

We could of course introduce a plan to replace all HVAC systems based purely on age. We have already mentioned that capital budgets are constrained, and have competing priorities, so a replacement plan based purely on the HTM guidance of 20 years may be unrealistic. So, do we say ‘Replace at 25 years or 30 years’, although this doesn’t take into account the impact of unavailability due to failure. Failures to some extent can be reduced by regular maintenance, and HTM 03-01 also talks about replacing motors within the lifespan, and, of course, other routine maintenance. An approach informed by risk factors may thus offer a sensible alternative. The most common way of looking a risk is to grade each factor, with the granularity of the grading a compromise between detailed knowledge and easy application. For most circumstances three or five levels are commonly used, and this is familiar with our 5 x 5 matrix model created by the National Patient Safety Agency (NPSA).²

Clinical risk

The clinical risk of unavailability should be considered, and should reflect the risk to an individual patient, or many patients. If we were to use a High, Medium, and Low grading system for simplicity, then a good example of a high risk would be an operating theatre with a UCV system. The failure of the UCV system could lead to unacceptable levels of colony-forming units (cfu), thereby increasing the risk of surgical site infection (SSI) for the patient. UCV theatres are traditionally used for higher risk surgical interventions such as orthopaedics, and it follows that here SSIs have a much higher consequence on successful clinical outcomes. Of course, this failure would only affect one patient at a time, assuming a single operating theatre, and if detected quickly, with further surgeries cancelled, only one patient may be affected. If we consider a Critical Care Unit, infection would impact potentially much higher numbers of vulnerable patients. Looking at this another way — and an isolation room housing an infectious patient could also be construed as a high risk, because failure may mean that other patients and staff are put at risk. Conversely, with a neutropenic patient in an isolation room, a failure in the ventilation would only impact the one patient.

Lower risk grades may be assigned to failure of a HVAC system supplying a general ward — where the impact may be more on patient comfort than infection risk. Clearly, the grading of clinical risk due to unavailability is complex, and is influenced by the type of patients and procedures conducted in a hospital. Furthermore, consideration should be given to future respiratory-related pandemics, and incorporating lessons learned from the Sars-Cov-2 pandemic in clinical areas designed to minimise spread by incorporating suitable pressure regimes.

The service impact is a measure of the degree of disruption that any significant failure of ventilation plant failure would have on the clinical service. This could range from insignificant disruption at one end of the spectrum — perhaps with the closing of one isolation room — to a complete cessation of the service, such as closing an operating theatre. Such plant failures can be even more significant in the case of older HVAC systems, where multiple operating theatres are supplied from a single plant. Instances of four or more theatres being supplied from a single HVAC plant are not unknown, and any plant failure in such a scenario would mean a suite of operating theatres having to be closed, with several operating lists cancelled, meaning a delay in surgery for many patients.

It is thus important that Estates teams liaise with clinical and project management teams when developing a risk that will be added to the Trust risk register, setting out the full impact of any outages, so that the Trust Board is fully informed of the consequences of non-funding. The service impact is also dependant on the duration of the disruption. In the case of a failure of a direct drive EC fan, the time to fit a replacement — assuming one is available — could be less than an hour. However, if failure occurred in an ageing HVAC plant where components are obsolete or in short supply, the disruption could last weeks, or even months, while replacements are sought.

Contingency plans

Hospitals should have contingency plans in place in the event of plant failures. In many ways the service impact is influenced by the contingency plans. If HVAC plant supplying a general ward fails, many hospitals will have escalation wards/areas where patients can be moved to, whereas if an HVAC system feeding an individual operating theatre fails, the contingency plan may be to move surgical procedures to another theatre, assuming one is available. A further complication here is where a theatre is set up for specialist procedures such as laparoscopic surgery, where another theatre with the same services may not be available. The contingency plan could also be wider in scope, for example seeing patients transferred to another hospital, although this can introduce delays, involve complex transportation logistics, and increase costs.

HVAC systems are expensive, and furthermore the lead time for installation and commissioning can be significant, not to mention the challenges of relocation of services and provision of temporary services. We have mentioned before that the potential loss of income from the closure of a single operating theatre for a single day could amount to five or six-figure sum. Patients may have to stay in hospital for a longer period, or be sent home to return at a later date, or may even need to transferred to another hospital Trust. The knock-on effect of this is ‘bed blocking’, which puts further strain on capacity. Even a relatively short-term failure can have a financial impact in the order of £50,000-£100,000. There is also the potential for legal claims on the basis of negligence. If an HVAC system requires replacing, then the funding envelope is likely to be in excess of £1 m — a worrying cost pressure on an NHS Trust’s already over-stretched budget.

Failures in hospitals readily attract the attention of the media and the public, and can damage the reputation of a hospital Trust. The level of media interest is likely to be largely based on the severity of the failure. A minor failure may thus only attract attention from the local media, but a more significant one — particularly if it has seen one or more patients sustain harm, may attract interest from national, or even international, media, potentially resulting in a severe loss of public confidence.

As patients can now to some extent ‘choose’ where they receive treatment, reputational risk can also impact on financial risk. If patients elect to move away from their local hospital Trust due to a ‘negative’ reputation, then the money for the treatment will move with them. Much of the funding is activity-based, and termed ‘Payment by results’ — for example where there is a tariff attached to each total hip replacement surgical procedure, or outpatient clinic appointment. The amount of funding will depend upon the activity, so if an HVAC system servicing an operating theatre where orthopaedic procedures are performed has failed, this will have a greater impact on the tariff received than, say, a cardiac ECG clinic. Furthermore, a significant failure impacting on patients could also lead to intervention by the Care Quality Commission (CQC) under its Key Line of Enquiry (KLOE) for the organisation being ‘well-led’, and might ultimately see the Trust or other healthcare provider rated ‘requires improvement’ or ‘inadequate’.³

Conclusion

With the cost pressures on NHS hospitals still severe, and competing demands being placed on the capital budgets available, it may be prudent to take a risk-based approach to informing HVAC strategic replacement programmes. This approach also enables the risk of a delayed replacement to be appropriately assessed, where it can be added to the appropriate risk register, to cater for a scenario where the organisation might be subject to regular scrutiny and review. It is important too to appreciate that a single risk cannot be considered in isolation. Ultimately, such an approach may also serve the healthcare facility’s patients best, and will ensure that public funds are being used optimally. Therefore, our key recommendations are:

1 Ensure an up-to-date and accurate asset list.

2 Conduct risk assessments on all HVAC systems.

3 Update the six-facet survey.

4 Develop a strategic replacement plan.

5 Link the replacement plan to the Trust risk register (ensuring that the Executive Board is fully informed).

References

1 NHS England and NHS Improvement. Health Technical Memorandum 03-01 Specialised ventilation for healthcare premises Part A: The concept, design, specification, installation and acceptance testing of healthcare ventilation systems. London: NHS England and NHS Improvement., 2021.

2 National Patient Safety Agency. A risk matrix for risk managers. London. NPSA, January 2008. https://tinyurl.com/5n8wre2m

3 Care Quality Commission. Key lines of enquiry for healthcare services. 13 July 2022. https://tinyurl.com/h4m895xr

Further reading

n National Quality Board (2024). Principles for assessing and managing risks across integrated care systems. NHS England,
4 December 2024. https://tinyurl.com/ysbap86h