Fluorescent tubes vs LED tubes
Flourescent Tubes vs LED
For over 50 years fluorescent tubes have carried the bulk of lighting in offices, factories and public buildings. Everyone knows them and we have adjusted to their disadvantages.
LED tubes for General Lighting - Replacement for Fluorescent Tubes
For over 50 years fluorescent tubes have carried the bulk of lighting in offices, factories and public buildings. Everyone knows them and we have adjusted to their disadvantages.
Fluorescent Tubes: A little Background
Fluorescent tubes are low-pressure Mercury vapour discharge lamps which produce UV light. The UV light hits the wall of a glass tube which is covered with Phosphor. The Phosphor absorbs the UV light and transforms it to visible white light.
The lamp needs high voltage to start the discharge, and a device that limits the current during operation. Most Fluorescent lamps have therefore a ballast and a starter, in newer lamps these functions can be performed by electronic circuits (more expensive).
Fluorescent Tubes: Main Disadvantages
Mercury is poisonous - If a fluorescent tube or CFL breaks, the whole building and its A/C ducts need to be cleaned (recommendation by EPA).
The light is not comfortable
Only some of the energy is transformed to light. The rest is heat, UV and an unnatural light spectrum. The light is pulsing with the mains frequency (50/60Hz), especially when many tubes are connected to only one power line, the light feels uncomfortable and can cause health problems.
Low power factor
In buildings where many tubes are installed the capacitive and inductive electricity waves will be unsynchronized. For more than 500 tubes, a special power control unit is needed to correct this problem.
Defect rate of new fluorescent tubes and CFLs
Due to glass breakage and leakage problems 5%-10% of defective new fluorescent tubes are considered to be acceptable.
Questionable energy savings and lifetime
An inductive kick from the ballast provides a high voltage pulse to start the lamp. If the lamp is frequently switched on and off, the energy savings of Fluorescent tubes and CFLs are very limited. The result being the tubes will age rapidly.
The Alternative: LED Tubes
A real alternative to fluorescent lighting is LED tubes.
They contain absolutely no mercury, do not emit UV radiation and are truly energy saving, lasting at least four times as long as fluorescent tubes.
Environmental Advantages of LED tubes
Less power consumption
An LED tube consumes only about 30% of the power a Fluorescent tube needs to produce an equivalent illumination
No poisonous substances in LED tubes
Fluorescent tubes and CFL lamps contain Mercury
Recycling of LED tubes is possible
Fluorescent tubes and CFL lamps are hazardous waste, cannot be recycled; LED tubes contain valuable raw material which can be re-used, e.g., Aluminum, PC, etc.
Carbon Dioxide
Led tubes save about 70% of the greenhouse gas a Fluorescent tube would create.
Long life
LED tubes have a life span of at least 4 times as long as Fluorescent tubes, 50,000 hours instead of 10 to 12,000.
LED Light is Directional
While Fluorescent tubes and conventional light bulbs distribute their light all around, LED light is directed to an angle of 120°. Luminaries are designed to shade off the non-useful portions.
For example:
For a lamp that illuminates a working area from above, only the fraction of the light that hits the working area is useful. All other light is lost radiated in other directions. When comparing the lumen, a Fluorescent tube needs to produce much more light to achieve the same illumination on a flat surface. Since in most cases 2/3 of the light of a Fluorescent tube is lost that way, an LED tube only needs 1/3 of the lumens to achieve the same illumination.
Economy and ROI
LED tubes are expensive, more than 10 times the price of FL tubes.
Aside of the environmental advantages, LED tubes return profit in the following cases:
Long operation hours
where the power savings justify the higher price
e.g., Wal-mart is replacing all Fluorescent tubes in cooled areas for LED tubes, ROI in half a year
Frequent light switching
Fluorescent tubes do not like switching, their lifetime declines sharply with frequent switching e.g., automatic staircase lights, elevator lights
Difficult locations
where the costs of exchange are substantial e.g., high ceilings, factory lighting, outdoor advertising light boxes / billboards
IN SUMMARY:
Characteristics of LED light vs. Fluorescent light
LED Light Advantages
• Directional
• The light comes out at an angle of 120⁰
• Light colour spectrum is easily adjusted through the Phosphor mix
• Natural Colours
• Colour rendering depends on Phosphor mix
• Instant starts
• Also in cold temperatures
• Operates best below 40⁰C
Fluorescent Light Disadvantages
• Not directional
• Fluorescent light radiates all around 360⁰
• Cold light
• Warmer tones only with high effort (expensive)
• Colours appear unnatural
• Better colour rendering only possible at significantly higher manufacturing costs
• Start with delay and flickering especially in cold environments
• Can operate in up to 60⁰C
