Creating and maintaining a healthy building

Graham Wright, president of HEVAC, explains why heating, ventilation and air conditioning should be monitored closely to ensure long-term efficient and effective operation.

The topic of heating, ventilation and air conditioning rarely raises a pulse among national newspaper editors.

It is seldom‑mentioned in the popular press unless these essential building services have gone wrong in a high profile setting, such as a hospital.

That was the case just two years ago when the air conditioning at the new £430 million Southmead Hospital in Bristol failed, causing the cancellation of 200 operations before the site had even opened.

And it was again the cause for the headlines surrounding the Royal Free Hospital in north London last summer when patients were left sweltering after the system broke down on two wards.

Such stories demonstrate why the end goal for any facilities manager in a healthcare setting should be that no occupant of the premises notices the HVAC system, or their absence, at all.

If they are working correctly, everyone from patients to porters will simply go about their business in a comfortable environment, without a second thought to the services functioning behind the scenes.

It is no secret that, central to any hospital HVAC system’s operation, is its maintenance and cleanliness. Ventilation ductwork provides the ideal breeding ground for potentially harmful bacteria, and hospitals have a responsibility to prevent the spread of infections as stated by the requirements set out in the Health Technical Memorandum 03-01. The document gives comprehensive advice and guidance on the legal requirements, design implications, maintenance and operation of specialised ventilation in all types of healthcare premises.

Ventilation hygiene
The Workplace (Health, Safety and Welfare) Regulations also cover healthcare and say that mechanical ventilation systems, including air conditioning, are regularly cleaned, tested and maintained to ensure that they are kept clean and free from contaminants.

Furthermore, the Guide to Good Practice TR/19 Internal Cleanliness of Ventilation Systems (published by the Building Engineering Specialists Association, BESA) offers professional ventilation hygiene providers in-depth guidance on how ventilation systems should be cleaned and maintained.

This includes criteria for ensuring new ductwork systems are protected during the installation period and before they are commissioned.

Meeting standards in cleanliness is one key part of the job for healthcare facilities managers. But in these straitened times for the health service, there is more that hospital facilities managers can do with their HVAC plant to ensure that not only is it keeping patients and staff comfortable and free from the threat of harmful bacteria, but also that it is performing as efficiently as possible.

A sound grasp of energy usage and where it is being wasted can make a significant impact on a building’s energy costs. Energy efficiency is an issue looming large for every major building owner, and it is no different for the nation’s healthcare facilities.

Energy usage
It is a little known fact that climate control and ventilation systems are responsible for nearly half of the energy consumption in non-residential buildings. What is more of a concern though is the fact that building design expectations in terms of energy consumption can be over-optimistic.

Research done by the Chartered Institute of Building Services Engineers (CIBSE) made a comparison between energy use in a model building as envisaged by Part L of the Building Regulations, and that of a real world example. It found that while hot water and heating performed similarly to the modelled building, annual consumption in Kilowatts per hour per m2 (kWh/m2) for cooling and the operation of fans, pumps and controls were far in excess of the expected levels.

Overall, the actual energy consumption was roughly 200kWh/m2 over and above the predicted figure, with cooling and fans, pumps and controls contributing the largest chunks of that usage. The outcome of CIBSE’s research was a document called TM54: Evaluating Operational Energy Performance of Buildings at Design Stage. The idea is that it can be used as a tool at design stage to avoid such vast performance gap between how a building performs on paper and what it does once operational.

For new build healthcare projects, such a guide could prove invaluable by facilitating better specification, with clear instruction to ensure the purpose and usage of the building has been understood by the construction team. It can also help to support improved installation and commissioning, which are equally important; and better operation, which requires the end user to have a firm grasp on the control strategy for the building, as well as monitoring and recommissioning where necessary.

Existing hospitals, however, are beyond this stage, and so require another set of tools with which to assess and improve energy efficiency. The Energy Performance of Buildings Directive, first introduced in 2010, and the 2012 European Buildings Directive, are the EU’s main legislation concerned with reducing carbon emissions in buildings.

These directives have resulted in further work, including the more recent British and European Standard EN15232: Energy performance of buildings. Impact of Building Automation, Controls and Building Management. This paper, as its title suggests, looks closely at how beneficial a robust controls strategy can be in terms of improving energy efficiency. At the heart of BS EN15232 is a structured list of controls and building automation technologies that have an impact on energy use in buildings. The Standard includes a method to define minimum requirements for controls in different types of building, including offices, hospitals, schools, retail and restaurants.

The Standard also offers a detailed method for assessing the impact of particular types of building control on the energy performance of a given building, assigning classes A, B, C or D to levels of control in a building and showing the resulting energy savings that can be expected.

Although spending hours interrogating such a document is unlikely to be a high priority for a busy building manager in a large healthcare site, it’s a worthwhile investment of time for those offering advice on energy-saving technologies in hospitals where finding savings in every aspect of their operation is on the agenda. The ability to provide evidence supported by a recognised Standard makes BS EN15232 a powerful tool.

Going back to CIBSE’s recommendation that clear specification is an essential part of the route to operating a building as closely as possible to its expected efficiency levels, the Standard can also help here. It will assist clear specification of a building energy management system (BEMS), and provides calculations to determine the impact of building controls on the energy efficiency of a building by comparing two energy-demand calculations using different functions.

In this way, specifiers can calculate the different potential costs and set these against the potential energy savings in the short and long-term – useful business insights into the effects of investing in BEMS.

Intelligent controls
Where HVAC is concerned, integrating climate control with other building systems using intelligent controls can improve the overall efficiency of a building and reduce energy use. Intelligent control is crucial, as it allows monitoring zone-by-zone within a building, ensuring that heating, cooling and ventilation levels are optimised to maximise comfort. Intelligent controls, in combination with remote monitoring, provide a comprehensive history of the system, helping to optimise settings and operation to maximise energy savings, improve comfort and enable preventative maintenance.

It is instructive for today’s hospital facilities managers to perhaps look back at what BEMS in these settings was used for in the early days. Often it would be no more than a glorified on/off switch for plant and central monitoring for faults.

Today, trusts such as Barking, Havering and Redbridge University Hospitals Trust, who oversee Queen’s Hospital in Romford, are taking energy wastage seriously. Jason Davie, energy manager, Queen’s Hospital for contractor Sodexo says: “As part of our drive to help the Trust meet its Carbon Emissions Reduction targets, buildings energy management and efficiency is key. For a complex modern buildings like Queen’s Hospital this is achieved through advanced BMS, which helps in monitoring and control of HVAC systems for internal environment. We are eliminating waste of energy in unoccupied areas by proactively programming our HVAC system inline with the occupancy times of individual business areas.”

Watchful monitoring through an integrated Building Energy Management System is most certainly the best way for hospitals to get a handle on energy performance, especially on a site as sprawling and complex as a large hospital.

Examining operations
Although not applicable to hospitals, the newly introduced Energy Savings Opportunities Scheme (ESOS) may well be a worthwhile exercise for a hospital facilities manager to undertake.

Following the ESOS model, an assessment would inspect an organisation’s energy use and examine the efficiency of that energy usage, thereafter making recommendations for improvements. For this reason, despite not falling under the Scheme, hospital facilities managers may want to pursue an ESOS style examination of their operations. Introducing energy saving measures recommended by an ESOS assessor could make significant cost savings.

An audit of just how comprehensive your current monitoring and controls strategy could yield plenty of information on which to lay the foundations for a better approach to running the buildings so many millions of us depend on.

Further Information
www.feta.co.uk