The need to reduce energy consumption has affected both commercial and domestic buildings with the use of new, energy efficient lighting being introduced by the lighting industry. New lights focus the light where it is most needed and switches or sensors turn off or dim the lights when they are not needed thus saving energy.
Lighting Control
Lighting control is a very effective way to save money as well as saving lighting energy consumption.
Lighting controls most commonly come in the form of a switch or a manual dimmer. To meet building regulations dimmers have to be close to the switch of the light / lights that it dims.
An alternative is for the lights to automatically switch on when movement is detected. PIR occupancy sensors can be hard wired into either the luminaries or the marshalling box that provides power for a group of luminaries. Nowadays, PIR sensors are sensitive to even the smallest of movements. They also have a much larger range and are designed to ensure that all sensors close by over lap to prevent a “dead” area. The time you want the light to stay on after you are out of range can be set. These can be both switch start and high frequency fittings.
Lamps
There has been a huge increase in demand for energy efficient Compact Fluorescents (CFLs) to replace the inefficient incandescent lamp. The price of CFL lamps is now much reduced as the demand increases and the technology improves.
To meet Part L (1) of the building regulations all new house builds must install a low energy pendent set. Only four-pin compact fluorescent 10/13W lamps can be used with these pendants, which are typically installed where lighting is left on for long periods of the day e.g. kitchen or hall.
These have high frequency electronic control gear for operating the four pin compact fluorescents ensuring quick flicker free starting.
CFL’s provide good quality lighting and save energy as they use up to 80% less energy for the same light output compared to incandescent lamps. Over a 15 year period they can save 1 megawatt hour and half a tonne in CO2 emissions.
Even though CFL’s have helped cut energy consumption, the lighting industry is determined to keep bringing new types of lighting out to help cut down on CO2 emissions and energy consumption.
LED’s (Light Emitting Diodes)
LED’s (Light Emitting Diodes) are the newest idea of energy efficient lighting and are a perfect replacement for all old filament lamps including halogen lamps in spot lights. Although the lamps cost more they are designed to last for longer and use 80% less energy thus saving money on electric bills. ‘If you replace a 50W halogen downlighter with a 6W LED you will typically save around £4 per year, or £70 by the time you have to replace the bulb’ – energysavingtrust.org.uk (26.10.11). That figure is for each lamp so if you replace all the lamps in your house the savings will mount up.
Well designed lighting
Well designed lighting also helps increase the efficiency of lighting. By concentrating the light where it is most needed, fewer fittings are needed. Allowance can be made for the effect of the walls, ceiling and floors that can reflect the light to other areas of the room.
High frequency control gear
A saving of another 20% in energy may be achieved by changing from the conventional switch start control gear to high frequency control gear. High frequency control gear needs less maintenance as it is an all in one unit compared to the separate starter, ballast and capacitor. Even more can be achieved if partnered with lighting control.
It also has benefits for the end user, with a flicker free start, automatic shutdown with failed lamps, flicker free lighting and silent operation.
Lighting Energy Conservation in the Commercial Environment
There are many opportunities to save energy in the commercial environment than there are in homes. Lighting can account for 50% or more of all energy consumption. It can be greatly influenced by improved lamp choice, improved fittings, more efficient control gear and lighting control solutions
Part L (2) or the Building Regulations for non-domestic premises in England and Wales plus the new Scottish Building Standards, both demand action to reduce wattage output for lighting per square metre of building.
Even more savings can be made when occupancy sensing is combined with daylight linking systems. These exist for both switch start and high frequency lighting. With switch start systems, the lights are simply turned on or off in response to occupancy and natural light levels. These systems have a delayed off so that they do not keep turning on or off depending on whether they are in shade or not. Daylight linking is used to dim the light depending on natural light levels. This needs a digital lighting control solution and high frequency lighting for fluorescents.
These types of systems also maximize lamp life, since typically they do not turn off in response to bright light, but dim down to around 10-15%. They can also have a delayed off setting so if no motion is detected for 20 minutes, they dim down to a set level, 15% for example, then after a further time period they turn off.
Energy Efficient Lighting in Schools
Most schools have Fluorescent strip lights however now it is possible to reduce the energy consumption by up to 50% and still maintain the same lighting levels. Most of the older fittings are fitted with T8 or T12 lamps. These can be replaced with the new more efficient T5 lamps and a conversion kit thus saving up to 50% of the energy consumption. A 35W T5 tube and 1W ballast produce the same amount of light as a conventional 58W T12 lamp and 19W ballast thus reducing consumption by over 50%. If it is a new block or the original light fittings are very old it is also possible, and perhaps better, to install new T5 light fittings.
