Emergency lighting and escape lighting are essential but they are often seen as a separate discipline from the rest of the building’s lighting. It can be seen as quite a specialised subject and some luminaire manufacturers make nothing but emergency and escape lighting.
One building developer, who shall be nameless, told me emergency lighting was an ‘unavoidable expense’. Another said it was the Cinderella of the lighting industry. Lighting designers and consulting engineers will sometimes pass decisions about the layout of emergency lighting to a luminaire manufacturer – maybe there needs to be greater awareness of the CDM regulations!
Possibly the most visible aspect of emergency lighting is the green escape sign and so we have reviewed some popular models.
Guidance and legislation on emergency and escape lighting is pretty daunting when you first approach it. In the UK, the two main standards are BS 5266:2016 and EN 1838:2013. For more detail, the most comprehensive and readable guide is LG12:2015 produced by the Society of Light and Lighting. One of the best aspects is that the guide includes worked examples of emergency and escape lighting design.
However, there are some basic aspects of escape signs that you need to be aware of. The first is whether the signs will be non-maintained (they only switch on when the mains lighting fails) or maintained (on all the time).
The other is whether you want manual (sometimes known as key switch testing) or self-test luminaires. To comply with the regulations, you need to regularly test emergency luminaires to show that they are still working. This needs to be recorded and the records kept somewhere safe. For any but the smallest of installations, automatic testing is most probably the better option.
One aspect of the design that is often forgotten is that the physical dimensions of the sign depend on the maximum viewing distance. Most signs are designed to be seen from 25m or less. If someone will have to view the sign from further away, for example a very long corridor, the sign needs to be bigger.
In the UK, the minimum (not the average) luminance of any part of the sign must be 2 cd/m2 or greater. This isn’t very much; it’s about the same brightness as the road surface of a well-lit motorway. Many LED escape signs comfortably exceed this. However, some countries, such as Germany, require a luminance of 500 cd/m2 for locations where the sign will be seen in daylight. As a result, many manufacturers offer signs where the luminance can be set to different levels.
Lastly, before deciding on a sign, always switch it on to see how uniform it appears. There are strict regulatory limits about the variation in the brightness/luminance of the sign face but a common failing of cheap signs is their lack of uniformity over the white and green areas. This, in effect, makes the sign harder to read. Exactly what you don’t want when looking for the emergency exit!
By recessed, of course, we mean that the batteries and drivers are above the ceiling (or in the wall void) and only the sign legend is visible.
This 6.5W sign is highly visible and its luminance of 500 cd/m2 means that it can clearly be seen in daylit spaces. Its slightly larger dimensions mean that it can be 32m from the furthest viewer.
The frameless legend panel has a click-lock fixing so you can quickly change it if the escape route direction alters.
Batteries are NiMH.
Aurora recently launched a brand-new range of emergency lighting and the Slim Exit sign is a good example. It is 4W and measures just slightly less than 30 mm deep by 200 mm x 300 mm. It is available as manual and self-test as well as maintained and non-maintained versions.
Elsewhere in the range is the Exit Blade which is a transparent sign with the LED light source mounted along the top. There is also an emergency twin spot, which was reviewed last month.
Batteries are Lithium Phosphate.
Emergency Lighting Products
The distinguishing feature of the Mexodus is its high brightness. Its luminance is over 500 cd/sqm meaning it can easily be seen in daylit interiors. This is achieved using a screen-printed polycarbonate legend panel. This is held in an aluminium frame and the legend design can easily be changed without the use of tools.
The base is solidly constructed of steel and aluminium.
The standard Mexodus functions as a stand-alone self-test exit sign. Alternatively, it can be connected to a DALI system and also configured for maintained or non-maintained operation.
Batteries are Lithium Iron Phosphate, LiFe.
Motus is the name given to their range of emergency lighting. As well as signs and pictograms, there are also escape and anti-panic luminaires both surface and recessed.
The body of the Motus housing can be surface, semi-recessed or fully recessed. Unusually, it is fitted with an opal diffuser and the pictogram is fixed to it.
At just 1W and 35 lumens it has a lower power consumption and light output of some signs. However, due to its optical efficiency, the maximum viewing distance of 25m the same as many more higher-powered units.
There are two models; 305 x 50 x 95mm or 360 x 55 x 95mm and both are available as self-test or central test versions.
Batteries are LiFePO4 or LFP.
This is a surface or recessed wall mounted luminaire. One of its advantages is the quick fit mounting mechanism. The legend has a white fixing trim which securely attaches it to the body of the luminaire. Black, chrome, brass and RAL trims are also available. The legend can be single or double sided.
The sign is available in two sizes and the larger 300mm version has a maximum viewing distance of 30m.
The Omega is equipped with the P4 Fastel fully automatic self-test system. Mains or static inverter versions are available.
Batteries are LiFePO4.
Mini Cylinder MC250
Emergency exit signs can tend to look alike but Philip Payne specialises in more aesthetic and designer-friendly luminaires. They also design bespoke emergency products. The company was founded over 50 years ago so it knows what it’s doing.
The Mini Cylinder is a good example where the frameless legend is topped by a finely finished cylindrical body. There are eight finishes available, one with a rather traditional name of Penny Bronze.
The company website has an animated cartoon describing their Specto-XT test and control system.
Batteries are nickel metal hydride.
The company has been going for almost 100 years and specialises in high end, heavy duty industrial and agricultural lighting. The dedication to build quality and pure function also means they are a firm favourite amongst architects whenever they want luminaires for iconic buildings.
The Maxwell emergency luminaire has the sign legend inside the stainless steel and polycarbonate body. It was originally designed for the food industry where the hose-proof and IK10 impact resistance means it can easily be cleaned in the harshest of environments. But it now finds uses in more public areas where its appearance gives an industrial chic to spaces.
However, it is smaller than some signs at just 100mm diameter and in emergency mode emits just 45 lumens. Larger are versions are available.
Batteries are NiMH.
An unusual feature of the pictogram used on the Combo is that it is comprised of two square parts. This means that instead of four pictograms, a single arrow pictogram can be used for up, down, left, right.
The pictogram is easily removed and the Combo can then be used for regular escape lighting. It has been designed this way in order to minimise stock levels for service companies or locations where there is a variety of buildings.
This 8W sign has a luminance of >500 cd/m2 and can be seen from 25m. The standard unit is IP40 but can be upgraded to IP54 by the addition of a gasket. Again, this can be done on site rather than ordered specially.
Batteries are Lithium Iron Phosphate, LiFePO4.
TM Technologie has a wide range of emergency lighting products and its sales literature and data was sent to us by its UK distributor Prime Light. I chose the S version because of its IP65 and IK08 impact rating. Also available are IP44, IP67 and low temperature (-15C) versions. More conventional applications would use the IP20 version, suffix G. The Ontec is also ENEC and Kitemarked.
The typical light output and power is 548 lm, 6.5W. Both recessed and surface options are available. Maximum viewing distance is 25m and the pictogram can be single or double sided.
The Ontec is available in manual, self-test, DALI and central battery versions.
Batteries are LIFEPO4.
This is a ready-to-use, straight-out-of-the-box sign. It comes supplied with various mounting brackets and four standard legends. As well as the illuminated legend, there is a row of LEDs on the underside of the body thus providing extra illumination where it is needed.
It is a surface mount unit for wall or ceiling fixing. There is also a ‘blade’ version which can be direct of suspended.
The standard unit is IP40 and has a 25m viewing distance.
Batteries are Ni-Cd.