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.

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.