History of energy savings in car park lighting

Many years ago T8 fluorescent tube lighting was the standard lighting used in all car parks and fire stairs. Over the past 10 years there have been many advances in technology. And there have been many energy saving options.

1. De-lamping

One of the simplest options to save money was de-lamping. This refers to removing one fluorescent tube from a twin fitting. It was a low-cost energy saving measure in areas which are over lit and can support a reduction in light output. A typical application of de-lamping in apartment buildings was to de-lamp lighting over spaces in car parks. Light levels are often much higher than the recommended lux.

2. Voltage reduction (fixed dimming)

Fluorescent lamps require full mains voltage in order to “strike”, but once warm can operate at a lower voltage. For older fluorescent fittings with magnetic ballasts energy savings of up to 25% can be achieved using Voltage reduction. This worked by lowering the voltage after the lamp has warmed up. Voltage reduction is typically not compatible with electronic ballasts found in relatively new fittings (less than 10 years old) and it may be compatible with control systems such as occupancy sensors.

3. Retrofit T5 tubes into existing fitting using T8 to T5 converters

T5 tubes were a more advanced, energy efficient tube. The T5 tube was thinner and used about 20% less energy than a T8 tube without reducing light output. The thinner T5 tubes could be retrofit into an existing T8 fittings using a T8 to T5 converters.  These also had a more efficient electronic ballast. The total energy savings could be as high as 35%.

T5 tubes were a good option for a few years, until LED technology advanced. T5 fluorescent tube lights are still however often found in apartment buildings. Even in new buildings.

4. Motion sensors

Lights running 24/7 in car parks represents a waste of energy and money. The first attempt to solve this was to install motion sensors to control the lights. This had several disadvantages. One motion sensor could control a large bank of lights. The means a large number of lights would switch on and off together. Large areas of the car park could be left dark. And many lights would switch on even though they weren’t needed. Motion sensor control of fluorescent tube lights could often reduce lamp life.

5. Retrofit LED tubes into existing fitting

LED tubes used up to 55% less energy than a T8 fluorescent tube. When LED tubes first came onto the market it was common practice to retrofit them into existing T8 fluoresecent tube fittings. While LED tubes are designed to fit directly into existing fluorescent fittings they typically require removing and replacing the starter. Many manufacturers claim LED may be installed without an electrician. However, as the starter or ballast may have to be removed from the fitting before installation it is recommended that an electrician conduct the works.

Modifying existing was not an ideal long term solution. And retrofitting LED tubes was superseded when the cost of LED fittings dropped. It became cheaper and better long term to replace an older fluorescent tube fitting with a new LED fitting.

 

Best practise Car Park and Fire Stair lighting

The best practise energy efficient lights for car parks and fire stairs are LED fittings with inbuilt occupancy sensors and step dimming controls.

During periods when an area is vacant the fittings automatically dim to provide low level security lighting while consuming relatively low power. When the occupancy sensor of a fitting is triggered the lamp increases to full brightness.

These can use 70% to 95% less energy than older fluorescent tube fittings. They can also provide significant savings when replacing LED fittings that run 24/7.

When purchasing a fitting and upgrading car park and fire stair lighting it is important to consider:

• The product warranty.
• Is the company reputable, have they been around for a long time? Will they be able to service any issues in the future?
• Do emergency fittings have an easily replaced battery pack, or does the entire fitting have to be replaced?
• Are the fittings progammable? Can it be programmed to stay on 24/7, turn off, of dim?
• Is the supplier able to provide an Energy Saving Certificates rebate?

 

Energy Saving Certificates

Energy Saving Certificates (ESCs) can only be generated when replacing older fluorescent tube fittings. They can not be generated when replacing standard LED fittings (that run 24/7) to best practise LED fittings with in-built motion sensors.