Low glare LED luminaires – a necessity for hazardous areas
01 June 2016
Glare resulting from a lighting installation is a real health and safety issue for hazardous area and heavy industrial facilities. The specific challenge it poses for lighting designers and a solution in the shape of the Gamma LED luminaire is explored by Gareth Bruce, Marketing Manager at Abtech.
Light emitting diodes (LEDs) are considered by many to be the future of lighting and integral to new luminaire design. Indeed their numerous benefits - reduced energy consumption, minimal maintenance and the generation of useable white light - have led to their increasing popularity over traditional lamp types such as high intensity discharge (HID) and fluorescent. These characteristics have been well documented and widely debated by the lighting industry. There is, however, one particular challenge to effective lighting design (and its successful implementation) to which LEDs are particularly susceptible: the problem of glare.
Glare is defined by the Illuminating Engineering Society (IES) as ‘excessive contrast in a visual environment that is distracting ’. This can result in a reduction in visual performance, a condition best avoided in heavy industrial environments. The worst instances of this condition are referred to as ‘disability glare’. This occurs when an excessively bright light source comes into direct contact with the eye. An LED by its very nature is a bright point light source and LED luminaires commonly use multiple diodes to form their light engine.
In the industrial or hazardous area environment, there is a requirement for higher lighting levels around pumps and rotating machinery as recommended by the IES and defined in numerous country and site specific standards. This is to ensure equipment is clearly visible and can be easily and safely maintained, day or night. These areas are typically lit by a dedicated white light source.
Hazardous and heavy industrial facilities are often congested with process equipment, pipework and structural obstructions. The requirements of the processes being undertaken and the physical constraints of the environment often determine the final location of machinery. This also means that the optimal location for a floodlight or lowbay is not always available. The challenge for the lighting designer is how to achieve the required lux levels in such areas without causing excessive glare.
In terms of luminaire design, point light sources of any type have traditionally been concealed within lighting fixtures to reduce the effect of glare. Reflectors are then used to transmit and direct the light out of the body. This often results in the reduction of luminaire efficiency. For LED luminaires such losses can be dramatic, so the focus of product design has been a drive towards ever increasing lumen output, irrespective of glare.
In recognition of this problem and in response to client feedback, some manufacturers have designed low glare LED optical technology which transmit light from indirectly mounted LEDs into the required field of distribution. This technology can provide uniform illumination without glare.
One advantage is that if looking directly at the luminaire, there is little glare or visual discomfort in the field of vision and the focal area is well illuminated.
These luminaires are ideal for use in height restricted or congested areas where there is a need for higher levels of white light, such as over pumps or rotating machinery. For hazardous areas, ATEX and IECEx compliant low glare units are also now available for Zone 1 & 2 gas and Zone 21 & 22 dust environments.
This technology, combined with the maintenance-free characteristics of LEDs, can provide lighting designers with a safe and long lasting solution.
About the author
Gareth Bruce is the Marketing Manager with Abtech Ltd based in Sheffield, UK. He has worked within the Oil & Gas industry for over 15 years primarily in the field of hazardous area lighting. He holds an MSc in Marketing and has an accreditation from Illuminating Engineering Society (IES ANZ).
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