r By Irwin BrooksrI recently came across an article on the web advising readers to have second thoughts about changing their overhead fluorescent light bulbs with the new LED replacement bulbs. (http://lumald.com/2013/05/29/leds-not-always-the-answer/#comment-8873) The article provides 5 reasons why you may not want to do this. Let’s take a closer look at these reasons and a counter argument to each one.rArticle Point 1. Let’s take a popular manufacturer’s T8 LED lamp and compare it to a fluorescent T8: The LED T8 is 18.86 watts and produces 1663 initial lumens (88.2 lumens per watt). A standard T8 lamp is rated at 32 watts and produces 2950 initial lumens (92.1875 lumens per watt). In this, they are not equal and you would be comparing apples to oranges. High performance T8 fluorescent lamps are rated at 3100 initial lumens (96.875 lumens per watt). You will use less energy with the LED T8, but you also get less light.rCounter Point 1. While it is true that the T8 fluorescent lamps put out more lumens per watt than current LED lamps, not all the light they generate is useful. What is useful is light radiated where we want it. Light that is radiated 360 degrees around a tube is not useful unless it is reflected (with losses) to where we want it. Thus, using the rating of just lumens generated is a misleading efficiency indicator.
Article Point 2. A T8 fluorescent lamp is an omni-directional source (throws light in many directions). T8 fluorescent light fixtures have internal reflectors designed to maximize this photometric attribute. T8 LED lamps are mono-directional (throw light in one direction only). This typically means the lamp is doing all the photometric work. This can lead to high glare, poor distribution, strange striations in the light fixtures, or poor performance of fixture reflectors. It is like trying to put a baseball glove on a kangaroo’s hand. It was just not made for that hand.rCounter Point 2. An LED light has a better ability to point light where needed and not “waste” light where not needed. LED tubes have a de-fuser lens and radiate light in 180 degrees. Fixture reflectors aren’t needed with LED bulbs. And, concerning the “high glare, poor distribution, strange striations or poor performance”, I have not seen any of those problems. Maybe they were an issue in the initial release stages, but not with the current generation of LED bulbs.
Article Point 3. Cost. A standard T8 fluorescent lamp costs between $2.50 and $6.50. T8 LED lamps can cost between $60 and $90 each.
Counter Point 3. The article is dated May 29, 2013. Boy how things have changed. Current costs of T8 ballast by-pass LED tubes are now about $9 each and are still falling.
Article Point 4. You can purchase T8 fluorescent lamps rated for 62,000 hours (based on 12 hour starts) and 60,000 hrs (based on 3 hour starts). A T8 LED lamp is typically rated for 50,000 hours.
Counter Point 4. True most LED bulbs have a 50,000 hour rating life and slowly get dimmer after that. But, with LEDs there are less components in the fixture to fail. A standard fluorescent has the bulbs and ballast, while the LED has only the bulbs. Ballasts also have a failure rating about the same as the fluorescent bulbs making the combined failure rate less than 25,000 hours depending on how many bulbs are in the fixture. No matter how you arrange it, adding the ballast into the failure rating equation makes LED bulbs the clear winner of reliability.
Article Point 5. When a fluorescent T8 lamp fails, you know it is dead because it will not start and you should replace it. T8 LED lamps do not really die. They are rated for 50,000 hours which means that at 50,000 hours they are at 70% of their rated lumen output (1164.1 lumens in this case). The T8 LED lamp will continue to burn (and reduce in light output) until someone finally says “hmmmm, this space looks dim.” This can be a liability issue because no one knows when to change the lamp to keep the light levels as designed. When they do replace the lamp, the cost is large and the lamp is difficult to recycle so the lamp ends up in a landfill.rCounter Point 5. When a light fails, which way do you want it to fail: A. completely dark or B. dim? I would rather change a dim light knowing a bulb will fix it rather than a completely unlit bulb only to find out it is a bad ballast, or power problem. And, I’ll have to climb the ladder less often since the reliability is higher.rMAIN POINT TO CHANGE TO LED BULBS. Let’s not forget the most important consideration: THE ENERGY USED. LED bulbs will provide the same level of task lighting using half the energy of fluorescent bulbs. Fluorescent bulbs require a ballast which gets hot and wastes a lot of energy in heat and requires more A/C cooling for the room. Also, LED lights work better in cool weather and have no turn-on delay. This is not even considering the fact that disposing of fluorescent tubes have EPA environmental considerations. I’ve made the switch and I’m glad I did.
Submitted by: Irwin Brooksribrooks54@comcast.netr801-427-1965