Dr. Bulbs


What is an LED?
LED stands for a light-emitting diode.
How do LED works?

A diode is an electrical component with two terminals which conduct the electricity only in one direction. With an electrical current, the diode emits a bright light around the small bulb. Connecting a diode to an electrical current excites the electrons within the diode, making them release photons, which we see as light. LED is not a new technology; it was presented in a journal by the Russian scientist Oleg Vladimirovitj Losev as early as 1927; however, the first LED with a visual spectrum was developed in 1962 by Nick Holonyak Jr, who is commonly known as the "father of the light-emitting diode".

Is LED ready for general lighting?

As LED technology continuing to evolve, the number of LED products available on the market continues to grow, including a wide range of lamps, integrated light fixtures (desk / task lights), under-cabinet lights, recessed downlights, track heads, and outdoor fixtures for street and are lighting. LED lighting is already in use in numerous array of locations and applications, such as home, office, restaurant, retail store, gallery, warehouse, hotel, cars, marine, track and display lighting.

Is all LED bulbs built the same?

Unlike previous lighting, LED lights are far more complicated from a technology standpoint. Thermal design plays a critical role in the rate of lumen depreciation. Color of LED comes from a phosphorus coating, which if applied inconsistently during manufacturing, will create different shades of color in the final product. Also, if LED is not built well, it will not achieve the efficiency expected from the LED light, results in using more power and product less light. Furthermore, if the LED fixture does not effectively pull the heat away from the LED, the life of the LED will be dramatically shortened. The key factor is how quickly the heat-sync can get the heat away from LED.

How do you evaluate LED products?

Lumen output is only part of the story and can be misleading. To fully evaluate an LED product one needs to review the overall system efficiency, optical control, thermal management of the LEDs, and know at what point in time the fixture will reach 30 percent lumen depreciation. Products with good optical efficiency and thermal management will be able to deliver more lumens, on average, than traditional HID products.

As the Department of Energy concluded in its Solid-State Lighting Commercial Product Testing Program: "Until the field of SSL technologies and supporting knowledge matures, any claims regarding performance of SSL luminaires should be based on overall luminaire efficacy (i.e., from testing of the entire luminaire, including LEDs, drivers, heat sinks, optical lenses and housing), to avoid misleading buyers and causing long-term damage to the SSL market."

How long does an LED last?

Literately, LED is extremely reliable by the nature of their design and the way they are constructed. In reality, the life of an LED is dependent on the engineering of the product it is in and the environment in which it is mean to operate. The exact same LED chip can last 1,000 hours in a poorly-designed product and over 50,000 hours in a well-designed product. In general, an LED is typically considered “dead” at 70% of initial light output.

How long is 50,000 hours?

Based on how long a LED is used per day, here’s what 50,000 hours works out to:

Hours of Operation 50,000 hours is
24 hours a day 5.7 years
18 hours a day 7.6 years
12 hours a day 11.4 years
8 hours a day 17.1 years
4 hours a day 34.2 years
How is LED considered a GREEN technology?

LED is environmentally friendly on many fronts. First, LED consume at least 85% less energy than incandescent, last about 20 times longer, is smaller and less fragile and switch on and off faster. LED emits light in a targeted direction instead of scattering it in all directions and doesn’t require or emit great amounts of heat. Incandescent and CFLs release most of their energy as heat, which is said to be about 80 to 90 percent. LED contains NO hazardous materials like HID or CFL. Aside from the above, LED also consist more benefits that are indiscernible:

  • Greatly reduced potential for lane closures and other productivity and inconvenience-related costs associated with maintaining a none-LED system.
  • No natural resources lost to produce the replacement lamps that contain mercury.
  • No fuel used to move old-technology lamps from the factory (most likely overseas), to the distributor, to the contractor, to the job site.

It’s important to keep in mind all the positive and powerful ripple effects that using LED technology can have on the environment.

Low power usageLED lighting is the most energy efficient lighting type available and gives the opportunity to turn lighting from one of the most costly expenses to one of the cheapest. Keeping that in mind it, it is worth seeking a light that is seriously frugal with its use of electricity. While halogens suck up 50 watts, top range LEDs need only 10 watts to achieve the same levels of brightness.

Unfortunately, some LEDs are not designed to be as efficient as possible and use more power than those from top manufacturers. Having the goal of cutting electricity bills to a fifth is an easy way to avoid LEDs that aren't up to scratch and achieve energy efficiency.

High light outputWhile brightness is one of the most noticeable points of comparison between different lights, it is surprising how many LED bulbs leave a lot to be desired in this area. Halogen bulbs are officially rated by the Department of Climate Change and Energy Efficiency to have an output of 720 lumens, therefore an easy way make sure you don't lose any light is purchase a bulb with the same output.

While 720 lumens is the benchmark that all LEDs should achieve, some retrofit bulbs achieve only a little over half that with around 380 lumens. Top range bulbs do match halogens with 720 lumens though, so ensure you note that.

Long warrantyOne of the easiest ways to spot a light that stands out from the masses is to find a bulb that is backed up with a lengthy, unconditional warranty. Manufacturers that are willing to back up their products with a warranty are much more likely to have produced something that is trustworthy and wont fail.

Look for a warranty of three or more years to ensure that you are selecting a quality light that won't fail or cause hassles.

Superior light qualityColour rendering index is measurement of the quality of light that is put out by a bulb. Rated out of 100, CRI determines how vibrant and true colours appear and enhances a room's look and feel. Leading LEDs have a CRI of 90, which ensures rooms appear exactly as they are intended and are always inviting. It is particularly important to avoid lights with a low CRI, as rooms will appear dull and colours washed out, which is not going to appeal to guests.

Long lifetimeLED lights have the ability to put an end to the constant hassle of replacing a blown halogen, only to have another one die just after the ladder has been put away. With the ability to last for 70,000 hours, LEDs can be left on in foyers and rooms for long periods of time without the chance of blowing out and leaving dark spots.