The lighting industry has seen an increase in the installation of energy efficient intelligent lighting systems, says Illumination Engineering Society of South Africa (Iessa) president Trevor Milne.
“This is as a result of multinationals being given the mandate to go green and reduce their carbon footprint, as well as owing to South Africa’s electricity generation crisis, explains Milne, adding that lighting contributes 19% of consumer electricity loads.
He says that cost-effective, energy efficient lighting systems have been installed in the basement parking areas of two buildings owned by financial services group Standard Bank, in Johannesburg.
A combination of T5 high-efficiency lamps, lighting supplier Lincoln Lighting’s Nanoflex expertise and developer, manufacturer and marketer of components for innovative lighting solutions Tridonic South Africa’s CorridorFUNCTION, together with consulting engineering firm Onzero Consulting, provided Standard Bank with an effective lighting solution.
The project involved removing two 58 W open-channel luminaires and replacing them with an intelligent 35 W luminaire equipped with Tridonic’s digital serial interface (DSI) occupancy sensors and ballasts.
“This technology is programmed to simulate Tridonic’s CorridorFUNCTION, which draws only 38,6 W when the area is occupied and 12 W, which is 31,1% of the T5’s light output, when vacant. The timers are set for a three-minute time delay,” says Milne, who is also the MD of Tridonic South Africa.
Meanwhile, Tridonic, along with consulting engineer Taemane Consulting, was also involved in transforming investment bank Absa Capital’s new headquarters in Alice lane, Sandton, into a building run by a digital addressable lighting interface (Dali) system.
“A separate control system for audio and visual rooms based on DSI was also needed, as well as push-button controls for personal preferences in the client suite areas. Tridonic installed 450 Dali MSensors, 20 Dali-DSI converters and one Dali control system. The lighting installations included the use of 1 800 PCA Excel one4all Tridonic ballasts. These digitally dimmable ballasts are equiped with about 4 KB of memory to provide two-way communica- tion and status updates and include simple switch control and easily and automatically adapt to the relevant lighting management solution,” adds Milne.
In terms of industrial lighting, to save energy, high-bay lighting has in some instances been replaced by T5 fluorescent technology in conjunction with motion sensors and daylight harvesting technology.
“New buildings are currently being designed to allow as much natural light into the buildings as possible. With daylight harvesting, a sensor measures how much natural light is coming into a building and determines what percentage of light is needed to provide adequate lighting for the building,” says Milne.
Building management systems, which control different aspects of a building, from the air conditioning to lighting, are also used to programme light use.
Retrofitting Old Buildings
Meanwhile, Milne highlights that older buildings, which are not being retrofitted, have outdated lighting systems that cannot be controlled as efficiently as those in new buildings.
“Lighting has changed 100% since buildings between 10 and 15 years old were constructed. These buildings are consuming more power for less light. Meanwhile, many older buildings also do not comply with the lighting regulations of the Occupational Health and Safety Act (No 85 of 1993),” he explains.
The Act states that employers have to ensure that the average luminance at any floor level in a workplace within 5 m of a task is not less than one-fifth of the average luminance on that task, that glare in any workplace is reduced to a level that does not impair vision, that lighting on rotating machinery is such that the hazard of stroboscopic effects is eliminated and that luminaries and lamps are kept clean and, when defective, are replaced or repaired forthwith.
Illumination levels are dependent on the activity being performed. Entrances, reception areas of offices and offices in general require 100 lux, while drawing offices need 500 lux illuminance. Activities such as rough grinding in machine shops, rubbing, dipping and spraying in spray booths and fine mouldings and inspection in foundries require 200 lux illuminance.
Further, the retrofitting of old buildings has decreased with the suspension of State- owned power utility Eskom’s demand-side management (DSM) project, in 2008, because of funding issues caused by higher coal and diesel prices.
Eskom hopes to decrease South Africa’s power consumption by 3 000 MW by 2012, and by 8 000 MW by 2025.
Milne says that the DSM project sub- sidised the cost of retrofitting old buildings with high-frequency lighting, which enables a power saving of between 20% and 25%. The project succeeded in decreasing power consumption; however, when it was suspended, the market migrated back to standard magnetic C9 lighting because the old technology was cheaper.
“In the commercial and retail market, there has been a technological shift to replace fluorescent and low-voltage lighting with light-emitting diode (LED) lighting. Whether or not LED lighting will replace fluorescent lighting entirely is a controversial topic; however, it is my opinion that it will,” says Milne.
In refrigeration, 80 W T5 luminaires are being replaced by 24 W LED clusters. The T5 lamp is significantly warm, while an LED cluster runs cool. The cooler the temperature, the brighter the light emitted by an LED and the longer its life span.
Therefore, because of the operating conditions, an LED cluster will outlast a fluorescant luminaire when used in refrigera- tion and should match the life span of the fridge, says Milne.
LEDs have also been used to illuminate signage, replacing 12 V halogen lamps, with up to 8 W LEDs.
“Tridonic’s revenue is growing steadily year-on-year as a result of consumers realising the benefits of LEDs and that poor-quality lighting technology, imported from the East, is not the answer.
“Iessa is also providing courses on new technology, such as LED, lighting control and the dynamics of lighting to ensure that it is understood to prevent the use of inferior products that ruin the credibility of the latest technologies available to the consumer,” concludes Milne.