Light output, Case studies and other Benefits
LED tube lights outperform fluorescent tube lights on both costs and output. Thanks to its directional output, LED tubes deliver light where it is needed – on your work surface.
Fig 1. 100 % Usable Light from a LED Tube
Fluorescent tubes on the other hand, waste as much as 30 – 50 % of their light – directing it towards the wall, the ceiling and the innards of the tube light fixture.
Fig 2. 50 – 70 % Usable Light from a Fluorescent Tube Light
Total Light versus Usable Light
A 18-watt LED tube produces 1800 lumens, does not need a ballast and has a high CRI. This LED Tube light output is better than the median usable light output from branded fluorescent tube light products. Given that 30- 50% light is trapped within the fixture and is never available for illumination, some of the branded products on the market produce barely 1309 usable lumens for a 40- watt tube light!
LED tubes produce 52% more light and use only half as much electricity. Clearly, the table is tilted in favor of LED tube light.
Long Life equals Maintenance Savings
Maintenance savings are another area where LED tubes beat fluorescent technology hollow. With a rated life of 50,000 hours, each LED tube easily outlasts fluorescent tube lights. Resulting in hundreds of saved person-days and reduction in maintenance budgets.
- Improved light levels in work areas
- 50% energy consumption
- Reduced maintenance hassles
Hard Evidence - Success Stories From Around the World
Energy efficiency, long maintenance free life span and safety are three important drivers for LED tube lights at myledlightingguide.com (MLLG). Here a few stories of businesses from around the world that have benefitted by opting for LED tube lights
a) Lowes at the Shell Harbor Square Shopping Centre, Australia – reduced CO2 emissions by 10.5 tons per annum and saved $1,779 every year in electricity cost and maintenance bills.
b) Belki, a Belgian poultry company installed 30 LED tube lights in their cold storage. The performance at -22 degree Fahrenheit is exemplary and energy consumption is only 18 watts per tube. Belki has only a two-hour window in which it can maintain lights as the work area is occupied 20 hours a day. Low maintenance LED tubes are a boon for them. At the time of writing, they were planning to replace 900 T8 fluorescent tubes with LED tube lights.
c) SOS Print + Media – replaced 484 fluorescent lights with LED tubes in their warehouse. They reduced their CO2 emissions by 149 tons per annum and saved $25,184 every year in electricity cost and maintenance bills. ROI – under 2 years.
d) Strata Committee of the Avanti building at 90 George Street, Hornsby, NSW Australia - 900 Fluorescent tube lights replaced by LED tube lights. Annual carbon emissions reduced by 312.5 Tons per year and expected savings of $57,931 per year.
e) Supermarket in Lyon – Replaced 40 watt fluorescent lights with LED tube lights. 40 tube lights replaced in the initial trial yielded annual energy savings of $ 894 and maintenance savings of $ 1000 per annum. The break even for the project on the back of energy savings alone was 1.8 years and less than one year when both energy and maintenance savings were factored in.
f) Underground parking area in China – installed 100, 15-watt LED tube lights and achieved annual savings of $ 3574 in energy costs alone.
LED tube lights are superior to fluorescent tube lights for several reasons
1) The Cost
LED tubes cost more upfront than fluorescent tubes. The cost of ballast needs to be figured into the cost of fluorescent tubes. Each fluorescent tube with ballast would cost close to $ 25. Recurring high maintenance costs and electricity charges add to the misery and ensure that fluorescent tubes cost more than LED tubes.
Air-conditioning loads are higher with fluorescent tubes and further increase running costs.
A study by the Maine Department of Environmental Protection (DEP) found that vacuum cleaners used in an area with a broken fluorescent light could be irretrievably contaminated with mercury. In addition, carpets continue to harbor mercury for several days and may need replacement.
A broken fluorescent light is all that it takes to write off a good carpet and vacuum cleaner. With fluorescent lights, these hidden costs can be substantial.
2) Performance issues
Studies have shown that children working under fluorescent lights in schools had 10 to 21 % lower learning rates and achievement scores on standard tests. Students demonstrated fatigue, hyperactivity and attention deficit under fluorescent lighting. This has important implications not just for schools but for business too.
Even at the lower end of the range, a 10 % drop in employee productivity should be an area of serious concern for any business. Adequate flicker free light has been shows to increase productivity by a few percentage points. This increased employee productivity is adequate to pay for the investment in LED tube light technology.
3) Risk of Injury from fluorescent lights
A broken fluorescent tube exposes users of the space to laceration injury from glass shards. The phosphor coating of the shards and the mercury content of the tube further complicate matters –slowing down healing, reducing blood clotting and increasing the risk of long-term neuronal damage. LED tube lights are free from these risks.
4) High voltage operation of fluorescent lights
A typical fluorescent light operates at 900 volts or more. Proper grounding and comprehensive safety precautions are necessary when dealing with fluorescent tubes. High voltages make it difficult to service fluorescent tube holders. If your office has several tubes controlled by a single switch, it may not be possible to cut the current to the fluorescent tube when it is serviced. LED tubes on the other hand use voltages that are far more benign.
5) Superior power quality is ensured by LED tube lights
Fluorescent lights have poor power factors and in large scale installation settings, this can adversely affect power quality. LED tube lights on the other hand have a high power factor (0.9) making them ideal for conserving power quality.
6) Use with timers, motion sensors, and other electronic controls
LEDs are not sensitive to frequent on /off switching. They are therefore ideal for coupling with intelligent lighting controls and occupancy sensors. Fluorescent lights lose 20 minutes of their life every time they are switched on and off. They are therefore not suited for coupling with these devices. Timers that use a connection to the neutral wire are not suited for Fluorescent lights as they have a small leakage current that may unnecessarily charge the capacitor in the ballast or cause the lights to flash on and off.
7) Outdoor use
Fluorescent lights are notorious for not working properly in cold environments. They are not suited to outdoor use in areas where the temperatures may fall below -4 degree C. LED lights on the other hand are not affected by a drop in temperature and are routinely used by retail stores in their refrigerators.
8) Lifetime brightnessFluorescent lights are notorious for rapid degradation of light output. The Department of Energy (DOE) tested several fluorescent products and a large portion of these products failed to meet rated light output after just 40 % of their rated service life.
9) The Mercury Problem
A fluorescent tube cannot do without mercury. Mercury is needed to produce visible light. Advocates of fluorescent lights point to a few studies that show that incandescent bulbs indirectly emit more mercury than fluorescent lights but that is only a part of the story. To read the rest of the story refer to our articles
a) LED Tube Lights II – Mercury from Recycled Fluorescent Tubes
b) Settling the mercury emission debate