5.4 Industry indoor
Techniques
General
The purpose of industrial lighting is to enable quick and accurate work, safely, and in a
good visual environment. Points of note are:
Illuminance on the task is the main criteria used for industrial lighting.
Therefore the extent of the task area needs to be determined.
Illuminance is often required for a vertical task. Illuminance on a vertical
surface is much more sensitive to changes in the spacing between luminaires
than illuminance on a horizontal surface.
Industrial areas generally contain obstructions that affect the lighting. For
overhead obstructions where possible install lighting below the obstruction. If
the area contains a few large obstructions ensure that all parts of the space
are lit by at least two luminaires. If the space contains multiple or extensive
obstructions the spacing between luminaires will need to be reduced to
counteract these and additional low level supplementary lighting may be
required. In all cases care should be taken to ensure obstructions do not
cause shadowing on the task.
For lamps used in industrial lighting a colour-rendering index of not less than
80 is required for all continuously occupied spaces. An exception is high bay
applications where HST/HSE lamps are acceptable.
In areas containing rotating machinery stroboscopic effects should be
eliminated or reduced by either using high frequency control gear (if
available) or by having alternate luminaires on different electrical phases and
ensuring that critical areas receive light in approximately equal proportions
from more than one luminaire. Alternatively lighting of the machinery may be
supplemented using local luminaires.
Emergency lighting will be required to aid in the safe evacuation of the
building when the normal lighting fails. In some industrial applications there is
an additional requirement to ensure all processes are in a safe and stable
state before evacuating the area. For others there is a need to continue
operations, even though the normal lighting has failed. The extent and nature
of the emergency lighting required is determined by the type of occupancy,
the size and complexity of the site and the processes involved.
Applications and Techniques
| 55
Industry indoor
Luminaires should be chosen to ensure they are suitable for the environmental
conditions in the space. Many industrial spaces have conditions of excessive
heat, cold, vibration or a corrosive atmosphere. Information on any airborne
chemicals is important as plastics and rubbers have differing resistance to
specific chemicals. Additionally in hazardous environments the lighting
equipment has to be carefully selected to ensure it does not pose a risk of fire
or explosion (see chapter on directives and standards).
Many industrial environments have impurities in the power supply due to
electrical motors running, or couplers connecting/disconnecting huge loads
giving spikes and voltage fluctuations. In conditions with poor quality of
power low loss magnetic ballasts should be considered instead of electronic
ballasts as they could be more durable and tolerant. Alternatively industrial
high frequency circuits with extra protection may be available.
At the design stage consideration should be given as to how the lighting
installation is to be maintained. Frequently, access to light fittings is difficult
and methods to improve ease of access should be considered, along with
use of technology that minimises the necessity for intervention for
maintenance.
Factory spaces - Points of note are;
Traditional factory spaces for heavy engineering and manufacturing have
high ceilings combined with a dirty environment. High bay lighting is most
suitable in these areas.
More modern manufacturing areas tend to have lower ceilings and a cleaner
environment. Linear fluorescent lighting is suitable for these areas and a
selection of mounting methods exist, from track mounting to catenary systems.
Lighting should take into account the possibility of moving overhead gantries
and moving vehicles such as forklift trucks.
Key luminaires:
56 | Applications and Techniques
Industry indoor
Workshops - Points of note are;
Tasks in a workshop vary from large tasks with little visual difficulty to small
task with high visual difficulty. The designer needs to understand the degree
of difficulty of the task to ensure that the task is adequately lit for the degree of
difficulty.
Generally ceiling heights are intermediate to low, and uniform lighting is
required across the entire space. Therefore either linear fluorescent reflector
luminaires or low bay luminaires with HID lamps are suitable
Key luminaires:
Assembly work - Points of note are;
Assembly work can vary from large tasks with little visual difficulty to small task
with high visual difficulty. Additionally colour discrimination may be of little
importance or essential. The designer needs to understand the degree of
difficulty of the task to ensure that the task is adequately lit for the degree of
difficulty.
In areas with lower ceilings fluorescent lighting is most suitable. The
advantages of this are the ability to produce fairly shadow free conditions, a
wide choice of lamps of different colour rendering capabilities and colour
appearance, and the ease of using lighting controls and emergency lighting.
For ceiling heights of 6m or less, care should be taken when using low bay
luminaires to prevent excessive glare.
Lighting should take into account the safety of pedestrians in the presence of
moving vehicles such as forklift trucks.
Store rooms - Points of note are;
For bulk storage at floor level it is generally important to avoid dense
shadows. A reasonable illuminance on vertical surfaces is required if the
reading of identification marks or labels is frequently necessary.
Applications and Techniques
| 57
Industry indoor
A suitable method of lighting these spaces is to use a closely spaced overhead
layout of luminaires with a wide distribution.
Lighting should take into account the safety of pedestrians in the presence of
moving vehicles such as forklift trucks.
Storage rack areas - Points of note are;
High racking can reduce lighting levels by up to 50%. Therefore an empty
space calculated for 300 lux will only achieve approximately 150 lux if high
racks are installed with narrow aisles.
It is good practice to light narrow aisles with runs of fluorescent luminaires
with narrow distributions arranged along the aisles to even out the vertical
illuminance from top to bottom of the racking whilst giving adequate
illumination along the aisle.
For mounting heights above 15m HID lamps may be used in luminaires with
a narrow lighting distribution across the aisle and a wide lighting distribution
along the aisle.
Cold stores - Points of note are;
It must be ensured that the lamp and luminaire chosen are capable of
operating within the low temperatures involved.
Thermally insulated fluorescent lamps may be used. Alternatively high pressure
sodium lamps can operate reliably at –40°C.
Food and drink processing plants - Points of note are;
The food and drink industry covers a vast range of working areas, where
ambient temperatures can range from –30°C to 50°C, from oil or fat vapour
laden atmospheres to hazardous environments where the lighting equipment
has to be carefully selected to ensure it does not pose a risk of fire or
explosion. Therefore great care must be taken to ensure a suitable luminaire is
chosen for the specific conditions.
Where food product is processed luminaires near the product should be
housed in an enclosure that prevents the lamp or any part of the luminaire
accidentally falling into the product.
The luminaire should be easily cleaned, maintained and re-lamped, having
minimum horizontal surface area upon which dust can rest and smooth lines
with no crevices in which fungus can grow (IP55 minimum).
58 | Applications and Techniques
Industry indoor
Schemes
Aircraft Hanger
Scheme: Aircraft maintenance hanger, 125m x 40m, varying height
Luminaire(s) used: C
oncavia XL 1000W HIE, mounting height 15m, Concavia L 400W HIE, mounting
height 9m and Concavia L 250W HIE, mounting height 7m
Hanger area floor: Eav = 591 lux ; Emin/Eav = 0.71
Applications and Techniques
| 59
Industry indoor
Schemes
Storage racking
Scheme: Storage racking, racks 5.1m long x 6m high
Luminaire(s) used: 12 Indus RDx 2x49W T16, mounting height 6m
Racking: Eav (vertical) = 137 lux
A train workshop lit using fluorescent battens mounted on
trunking. The luminaires are positioned between the trains to
give a good vertical component of light falling on the sides of
the carriages.
Factory lighting using Popular Range luminaires. The
luminaires are track mounted to allow easy modification of the
lighting layout. It may therefore be easily adjusted to suit the
requirements or any changes to the layout of the factory space.
60 | Applications and Techniques
Industry indoor
Low-bay luminaires lighting a machine workshop. The Lopak
luminaires provide a good even illumination, allowing work
upon complex machines with minimum shadowing. Note that
this task has no special requirement for colour discrimination. If
this was the case the lamp type should be chosen to show
colours correctly.
Hi-bay luminaires lighting a large factory space. The luminaires
need to be able to cope with the relatively hostile and dirty
environment, and due to problems of access maintenance
requirements for the luminaires need to be minimal. The shape
of the luminaire aids in self-cleaning, directing air within the
reflector to help remove dirt, and the use of high pressure
sodium lamps ensures a long lamp life.
Applications and Techniques
| 61