Achieving best standards for healthcare

HTM-specified modular vertical AHU installed at Belfast Hospital.
HTM-specified modular vertical AHU installed at Belfast Hospital.

Andrew Robinson, Managing Director of HVAC supplier Exi-tite, explains the role of technical memorandum HTM-03-01 for ventilation in healthcare.

Our healthcare facilities need to provide clean and safe environments for patients and the people who work there so, from the specification and design of equipment through to the installation and subsequent maintenance of systems, achieving the highest standards is crucial.

Health Technical Memorandum (HTM) 03-01 provides comprehensive guidance on these requirements and highlights different solutions for different applications.

Design and installation

The first part of the memorandum is aimed at new installations and major refurbishments of existing installations. It should be considered as the standard to be achieved. The guidance details legal requirements for compliance and covers all aspects of equipment selection, ventilation and control strategies, alongside the required levels of installation.

Although it identifies that the default method should, whenever possible, be natural ventilation followed by mixed mode (natural with mechanical ventilation), with mechanical ventilation being the last option, the guidance also explains why different applications need bespoke solutions. For example, areas such as operating theatres, providing acute care with high occupancy levels and intensive use, will often require close control of the conditions, with patients particularly at risk from airborne infection.

Ventilation of non-healthcare facilities on the hospital premises should be designed according to the application and specific guidance relating to the activity should be followed. Away from the hospital setting, other types of facility such as GP practices, health centres, care homes and hospices require a risk assessment of the nature of the treatment and condition of the patients to determine the extent to which HTM-03-01 should be applied.

The construction of ventilation equipment such as air handling units (AHUs) must meet strict criteria to avoid contamination. Examples of this are the use of smooth stainless steel or powder-coated internal panels and filter frames, low leakage dampers, copper or finless frost coils and access doors with two-stage openings.

If the correct manufacture of ventilation equipment is essential, so too are well designed systems able to control the temperature, air pressure and humidity levels inside the facility. If the main requirement is providing filtered fresh air and removing stale and polluted air, with experience it is also possible to deliver energy efficient climate control solutions that can utilise energy recovery to reduce carbon emissions without mixing supply and extract air, thereby maintaining sterile environments.

For a recent installation at Belfast City Hospital, we used two vertical modular AHUs manufactured in line with HTM-03-01 to provide 7200m3/h of supply and extract ventilation for two operating theatres. Each system included energy-saving runaround coils, which remove energy from the extracted air and transfer it to the incoming fresh air supply, using a water circuit to ensure sanitisation levels without the risk of contamination from a thermal wheel.

System efficiency is a key focus point of Part A and the guidance is that solutions with the lowest lifecycle environmental cost should be specified. In particular, fans represent a significant opportunity to save energy and reduce carbon emissions as they use approximately 40% of all electricity in ventilation systems. HTM-03-01 recommends using electronically commutated (EC) fans.

In addition to new installations, older hospital buildings may find that their ventilation systems need to be improved in certain areas. This is sometimes as a result of poor initial design but can also be because a particular part of the hospital is now to be used for a different purpose.

Retrofitting equipment that can provide ventilation in an energy-efficient manner in this type of setting can be costly or prove difficult, often due to space constraints. In such situations, Exi-tite uses the CGL solution from German manufacturer Wolf. This energy recovery product is about the size of a small wardrobe and is capable of an airflow of 1.1m3/h. The unit’s compact dimensions mean it can fit through a standard room door, easing many installation issues. Ductwork can be installed in various configurations to serve a dedicated space and provide energy recovery and CO₂ regulated ventilation with a range of filtration options in a silent manner.

Choosing a supplier with the expertise to handle all design, support and supply needs in-house means it is possible to maintain close relationships with consultants, installers and end users to ensure problem-free project delivery.

Operation and maintenance

Part B of the guidance applies to the maintenance and operation of any specialised ventilation system installed in all types of healthcare premises, irrespective of the age of the installation.

It covers all aspects from statutory requirements to service intervals, with minimum standards laid down for ventilation equipment including AHUs, humidifiers and filters. Strict policies for annual inspection and verification are also in place, along with advice around the routine servicing of equipment such as air conditioning split systems and chilled beams.

Maintaining a sanitised environment during ongoing servicing and maintenance of a system presents its own challenges. One of the ways we have addressed this in recent healthcare projects is by installing two modular AHUs in a compound with a service corridor equipped with hand wash basins and hosepipe connections.

Key to compliance

The need to deliver ventilation for healthcare facilities makes choosing the right partner more important than ever. Every project has its own specific needs and the ability to deliver bespoke solutions with the highest standards comes with experience. Understanding HTM-03-01 is the key to ensuring compliance.

Related links:
Related articles:

modbs tv logo

WIN a Bang & Olufsen speaker system – in the MBS subscriber prize draw 2024

Subscribe, or renew your free subscription, to MBS between 1st June and September 30 2024 and you could win a great prize.

Going Underground

ABM has announced a significant contract win with Transport for London (TfL) to provide mechanical and electrical (M&E) services across the London Underground network.