Being the responsible earth loving citizen you are, you decide one weekend that its time to replace your old fashioned light bulbs with the new LED bulbs. And why not? LED bulbs are super efficient, and last on average five times longer than conventional bulbs. So you jump in your ride and head to your favorite retailer, and see a 6 pack of LED bulbs for $20 bucks. “What a deal” you say. So you purchase a couple packs race back to your pad, and go to town replacing your inefficient incandescent bulbs with new super energy efficient LED Bulbs. After climbing around on a ladder replacing all the bulbs in your home you are eager to flip the switch to see the fruits of your labor! Only to find out that they don’t work like the old bulbs did! You have some that work fine, but others wont shut off all the way (ghosting) or flicker horribly when you try to dim them. What the heck?! Did you get a batch of bad bulbs? Is your house possessed? Well I can’t rule out possession, but here is what is likely happening.
First a little history. Back in 2007 to encourage energy efficiency, Congress passed a law mandating that bulbs producing 40 watts, or more worth of light meet certain efficiency goals. Conventional incandescent light bulbs don't meet the required standard, so the law prohibits manufacturing or importing them into the United States. This legislation opened the flood gates for Chinese manufactures clamoring to get a piece of the U.S. LED pie. The problem is that there are little to no regulation, or standards in place policing this industry. Any factory capable of making an LED bulb is shipping them into the U.S. to take advantage of this new lucrative market. Consequently this loose regulatory environment has lead to inconsistent performance from brand to brand. The most notable issues are color accuracy and dimming capability.
So why don’t LED bulbs just work? Well the the very feature that makes LED bulbs so attractive to customers, and drove the 2007 legislation is at the heart of most of these problems. The LED bulbs are just to efficient! Yup you heard me right. Most of these problems are caused because LED bulbs don’t draw enough power for your dimmer ,or switch to function appropriately. Modern Dimmers, and switches that were not built specifically for LED lighting loads were (in most cases) designed to work with bulbs that had a minimum wattage of 40 watts. In the old days of incandescent lighting a 40 watt bulb was a relatively low output bulb with 65 watt and 100 watt bulbs being more common for primary light fixtures in a home. Now if you want a new LED bulb that has comparable output to a 65 watt incandescent bulb the new LED equivalent bulb only uses 5-7 watts. So the problems you are experiencing with the new LED bulbs is more than likely because the electronics inside your dimmer or switch cant function as designed because the load you are presenting to the switch falls way bellow the minimum wattage of what the manufacture intended when they designed the switch or dimmer.
“ I need new LED compatible dimmers then?” The short answer is yes. You should always make sure you are using LED compatible dimmers or switches when controlling LED lighting, but here is the frustrating part. Just because you buy an LED compatible dimmers/switches to go with your new LED bulbs doesn’t necessarily guarantee that your not going to still have problems. Remember earlier when I said there little, or no standards in place for the manufacturers, well this presents a real problem for consumers. Unlike their incandescent counterparts LED bulbs are much more complex devices. LED’s by their very nature run on DC voltage not AC. So in order for the new LED bulbs to work with the existing lighting fixtures LED manufactures have to build a ballast circuit into the light bulb itself to convert the high voltage AC electricity to low voltage DC electricity so the LED bulbs can work. These ballast are the rest of the problem. The design and tolerance for the ballasts very greatly from one manufacture to another, and often are even different between wattages from the same manufacture! Because of this lack of standardization you can often still run into lighting problems when you are using LED approved Dimmers or switches. The problems stem from the fact that between the different switch/dimmer designs and the inconsistencies in LED manufacturing process it is not uncommon to still experience compatibility issues with certain combinations of dimmers and LED bulbs.
All hope is not lost! One of our partners Lutron Electronics is a leading provider of Lighting control systems and has lead the way with several online tools to help consumers pick compatible products before they purchase them. If your project is more involved or you just don’t have time to figure out the details you can hire a Lutron certified professional like myself to help you design and procure the appropriate lighting products for your applications. When designed and executed correctly LED technology is a great way to conserve energy and reduce a home's carbon footprint.