Although led lighting has proven highly efficient and effective in a wide variety of applications, one barrier to its adoption in large spaces like auditoriums is the difficulty of integrating it with existing dimming control systems. Unlike incandescent bulbs that work with almost any dimmer, LEDs perform differently depending on the dimmer being installed. Using the wrong combination of lights and dimmers can cause a variety of problems:
- A limited dimming range – the LEDs may turn off before the dimmer slider reaches the bottom. (The newer the version, the less likely this is to happen – the latest products on the market can reach levels as low as 5%.)
- “Pop-On” – after being dimmed to a low light level and switched off, LEDs will sometimes not turn on until the dimmer is adjusted.
- Flickering – dimming LEDs may flicker or turn off with fluctuations in voltage.
- Changes in color when dimmed – most LEDs do not actually change color the way incandescents do, but they may appear to turn blue.
The LED market is changing quickly, and new versions are constantly being introduced that present fewer dimming problems. But for now, these issues can be largely avoided by determining beforehand whether a specific make and model of LED will perform as required when teamed up with a specific dimming system. The best way to make this determination is through observation – performing a mockup of the lights and dimming controls, and then testing over the full dimming range. On-site experimentation with multiple makes and models of LED luminaires may be the best way to find a product that will deliver the desired performance.
If a mockup isn’t possible, it will help to use a combination of LED sources and dimmer that has proven successful in other recent applications. Colleagues and manufacturers’ representatives can be sources of reliable information. Be sure to ask for case studies that are no older than six months, and be aware of any production changes made to lamps and dimmers that may affect the dimming performance. Products are evolving so quickly that their technical specifications may actually change between the time they’re ordered and the time they reach the job site.