5 Ways to Control Lighting for Maximum Energy Savings
Published April 2013
As you continue research for your lighting retrofit project, you will find many energy-saving methods available to you aside from simply reducing watts and energy used by the lamps you choose to use to light your facility. The most direct savings does come from this wattage reduction, but adding lighting controls to your lighting retrofit project can dramatically impact energy savings. Lighting controls range from fully automated control systems managed by computer programs, to less technological, manual methods, some are even as obvious as “good occupant habits,” like always turning lights off in an empty room. But occupant habits aren’t always good and fully automated systems might be overkill for the lighting management of smaller facilities.
These five ways to control lighting for maximum energy savings are all relatively easy to implement alongside your lighting upgrade to increase savings, but most of them can also be installed or carried out after a lighting project is completed.
All light sources use less energy when dimmed and two primary types of dimming can be used, depending on the lighting application. Continuous dimming brings light levels down incrementally; often on a sliding type switch or you may have seen them on a knob which turns light levels up and down. This type of dimming offers a smooth transition between light levels. Step dimming is a method of firing some or all of the lamps in a fixture, depending on the need for light. Commonly referred to as bi-level switching, in reference to fluorescent lamp systems, this dimming method can offer more than 2 levels of light. This method is seen in classrooms, where only the lights in the front near a projection screen are turned off or is used to turn off lamps near a bank of windows on the end of one large room where less light is required during bright times of day.
2) HIGH END TUNING
Tuning down the high end of your lighting system means to slowly adjust from 100% of your lighting system’s capability down to the most appropriate amount of useable light required for an area’s needs. Example: Recommended lighting level (range in foot candles) for kitchens in the food service industry is 50-100 foot candles. Your facility may be lit at 100 foot candles with the current system, but employees are still able to safely and comfortably perform all required tasks at 75 foot candles. Over a period of days, by trimming off the top using controls, and setting the new ‘maximum’ light level at 80 foot candles, reduces overall energy usage. Typical lighting energy savings from high end tuning can be 10-20%.
3) OCCUPANCY SENSORS
Using passive infrared (PIR), ultrasonic or dual technology, these sensors respond by turning lights ON when the presence of a human is detected and then automatically turn lights off when the presence is no longer detected for a specified amount of time. The use of sensors is most suited to areas where lights are commonly left on when not occupied including:
- Storage areas
- Conference rooms
- Hallways / Corridors
4) VACANCY SENSORS
Using the same technology as Occupancy Sensors, these devices only turn lights off when no occupant is detected. Someone must manually turn the lights on in a space where vacancy sensors are employed. This may seem counter intuitive to some, but consider spaces such as offices where someone enters for only a moment to retrieve an item and then leaves. In this scenario, an occupancy sensor would turn lights on, and leave them on for 10-30 minutes depending on how they were commissioned, wasting energy in an unoccupied room. Vacancy sensors grant the highest level of energy savings because lights cannot turn on automatically.
5) PERSONAL LIGHTING CONTROL
By providing individuals the option to control light levels which accommodate the tasks and activities in a specific area, some facilities could see a 20-60% lighting savings. The ability to adjust light levels in their own workspace, gives occupants the exact light level for their eyes and the task they are performing. There has been some research to suggest that in addition to energy savings, personal lighting control also increases productivity.
Have you implemented any energy saving lighting controls?