Shedding light on hospitals
Reliable, clear and effective lighting in hospitals plays a key role in all aspects of operational effectiveness, patient recovery as well as staff productivity. Nathan Cole explains the benefits of lighting control.
Modern NHS hospitals are complex, often multi-site, environments that rely on staff being able to work across departments and even different buildings. In medical emergencies seconds are vital, so being able to see clearly through a high quality lighting infrastructure can make all the difference when it comes to patient care.
Tighter budgets, increasing amounts of environmental legislation, and greater financial accountability means that NHS hospital and healthcare estate managers are under growing pressure to ensure that any money spent provides excellent value and enhances the wellbeing of staff and patients alike. It’s why lighting control is an increasingly important part of any building services infrastructure.
Lighting control integrates sensors and luminaires to determine when and where lighting is used within a space. A lighting control system allows light usage to be accurately monitored and managed. Controllable, adaptable lighting systems can create more comfortable environments for people, leading to more productive working experiences for healthcare professionals and an enhanced sense of wellbeing. It also helps to aid the patient recovery process by positively influencing sleep-wake cycles, hormone release, eating habits and digestion, body temperature, and other important bodily functions.
Responding to specific footfall levels provides a huge opportunity to lower energy use, as light settings can be pre-set in accordance with demand. In addition, the ability to trigger alarms in these events to then automatically change settings back into a pre-defined mode is another example of how energy spend can be lowered. Lighting control therefore has a distinct impact on operational expenditure and the reduction of energy related CO2 emissions.
A wide range of guidance exists to help create optimal lighting provision in the built environment. BS 8300-1:2018 and Part M of the Building Regulations both contain such information, with the latter addressing issues such as visual contrast between surfaces, light reflectance value (LRV), illuminance and colour rendering. For emergency lighting, BS 5266:1 2016 provides information on the correct lighting provision, minimum levels of illumination, duration of operation and the maximum brightness levels needed to prevent glare.
Lighting control should be the rule rather than the exception and BS EN 12464-1: 2011, the European standard for lighting indoor workplaces, is having a significant impact. This standard addresses the design and development of lighting schemes for specific tasks or activities and encourages designers to consider all available forms of lighting. It also provides guidelines about the use of lighting controls and recommends ways to illuminate rooms only when they are in use.
While all of these documents should be read, understood and acted upon, the Department of Health and Social Care’s series of Health Technical Memoranda (HTM) sets out healthcare-specific standards for building components.
HTM 06-01 provides information relating to the design, installation and testing of all fixed wiring and integral electrical equipment used for electrical services. It promotes good practice for those responsible for the design, installation, commissioning, operation and maintenance of electrical services. By identifying key requirements, it provides a point of reference to legislation, standards and other guidance pertaining to electrical systems, and should be read in conjunction with BS 7671.
Hospitals need to rely on 24/7 ‘always on’ lighting and HTM 06-01 states that, ‘Where lighting control systems are installed, the installation should be such that a failure of a lighting controller, or associated switch or sensor or circuit, does not affect both lighting circuits (where installed). Additionally, when normal mains power is lost and subsequently restored (either mains or generator), the luminaires (and associated controls) should return to the state they were in prior to the outage.’
It also recommends that switches should have a contrast with the background and the selection of lighting control systems should give consideration to ease of maintenance and future modification. In addition, any clinical risk room rated Grade C and above should have at least two circuits from two different supplies, while HTM 05-02 requires that at least two lighting circuits with emergency lighting back-up are in place.
In practical terms this means that lighting circuits should be split and a supply to each circuit provided. Therefore, wiring a room from a single lighting control module (LCM) with dual supply is the simplest method of achieving maintained lighting, as it reduces installation costs and is easy to test and link to emergency lighting circuit. When it comes to choosing an LCM there are a number of factors to consider: a system must conform to HTM 06-01 as well as perform reliably, be easy to install, have a long life, be robust and offer a good return on investment.
Two different supplies from two separate phases can feed a dual supply LCM. This also allows the connection of two maintained live connections for connection and testing of emergency lighting. The way that this type of LCM operates is relatively straightforward – if Supply 1 fails the relay drops out and Supply 2 supplies the LCM, while if Supply 2 fails the relay stays energised and Supply 1 continues to energise the LCM. Likewise, the mains voltage is monitored and, if configured, luminaire output levels are saved and upon restoration of the supply the luminaire levels are returned to those prior to the failure.
Pluggable intelligent LCMs offer a simple and cost effective solution to power outages, are easy to maintain and future proof. The sensors that work as part of the system eliminate physical contact with switches, automatically regulate light levels, and provide knowledge and information on key data, so more informed decisions can be made.
For the electrical contractor, the combination of a pluggable luminaire and sensor leads eliminates wiring errors and are easy to install, with less time required to plan the wiring layout. For healthcare estates managers, the automatic control of maintained and non-maintained supplies means that no additional hardware is required, patient disruption in the event of a power outage is minimised, and an environment that has optimal comfort conditions is achieved through the creation of sophisticated lighting scenes and groups.
Hospitals and other healthcare estates are constantly evolving environments that must be flexible enough to accommodate new layouts and changes of use, as and when required. LCMs can be easily re-commissioned in the event of layout changes and are fully scalable.
The healthcare sector, more than most, is required to provide a high quality built environment, which must be sustainable, compliant and resilient. In an NHS hospital, where continuity of service is imperative in order to ensure the highest levels of patient care, wellbeing and smooth running of the facility, healthcare estate managers must take new and creative steps to address potential issues and work with manufacturers that can help them achieve their objectives. Therefore, the increased use of advanced lighting control technology should be at the forefront when it comes to complying with HTM 06-01 and other relevant legislation.
Nathan Cole is global product manager at Ex-Or by Honeywell.
