LED Lighting Guide

What is LED Lighting?

LED, short for light-emitting diode, is one of the most rapidly developing lighting technologies. In its simplest form, LEDs produce visible like when an electric current passes through its semiconductor. This form of light production is quite different from incandescent or CFL, which use vacuums or gas, respectively. LEDs offer better light quality and overall lifetime compared to incandescent and CFL lighting alternatives.

How Does an LED Light Work?

LEDs are a semiconductor light source that generates spectrum light by passing a unidirectional current through it. How does this happen? The semiconductor has two layers, one negative layer (cathode) with free-floating electrons and one positive layer (anode) with openings for electrons often called holes. When an electric current passes through the negative layer into the positive layer, it releases photons through those holes, creating light.

How Do I Convert Watts To Lumens?

When buying LED lights, look for lumens, not watts. Watts = lumens / (lumens per watt). To take out a lot of the guesswork, here is a simple chart you can follow.

• 100W incandescent = 1600 lumen LED
• 75W incandescent = 1100 lumen LED
• 60W incandescent = 800 lumen LED
• 40W incandescent = 450 lumen LED

What Color Temperature Are Led Lights?

LED color temperature is measured in Kelvin (K) and commonly described as warm, cool, and daylight.

• Warm = 2200K to 3000K
• Cool = 3500K to 4100K
• Daylight = 5000K to 6500K

For comparison and replacement of older lighting sources, candle, CFL, incandescent, and halogen are 1900k, 2700k, 2800k, and 3000k, respectively.

What Is the Equivalent Wattage for Led Bulbs?

If you are looking to make a direct replacement from your existing incandescent lights to LED, you can follow these suggestions:

• Incandescent 40 W = LED 8 W
• Incandescent 60 W = LED 13 W
• Incandescent 75 W = LED 17 W
• Incandescent 100 W = LED 20 W

How Long Do Led Light Bulbs Last?

While incandescent bulbs are designed to last an average of 1,000 hours, LED lights can have a lifespan of 25,000 to 50,000 hours. This is also significantly higher than halogen and CFL, whose lifespans are 2,000 and 10,000 to 15,000, respectively.

Do LED Bulbs Save Energy?

LED lights are designed to use 75% to 80% less energy than incandescent lights and roughly 18% less than CFL lights.

What Causes LED Lights To Flicker?

LED lights can flicker due to voltage fluctuations in your home's wiring, or it could signal loose wiring in your lighting fixture. In both cases, call your electrician to take a look.

How Much Can Be Save By Switching to LED Lights?

The average American household uses 40 lightbulbs and has an electricity rate of 13 cents per kilowatt-hour. If all 40 lightbulbs were converted from 75-watt incandescent to 11 watt LEDs for five hours a day, homeowners could save upwards of $600 per year.

What's even more compelling are studies at the national level. The US Department of Energy estimates that if the adoption of LED lighting technology continues, by 2027, LEDs' widespread use could save around 348 TWh of electricity. That's terawatt-hours, which is one billion kilowatt-hours! For context, one 100-watt bulb turned on for ten hours is equal to 1,000-watt-hours, or one-kilowatt hour. This potential energy savings is equivalent to the annual amount of electricity produced by over 40 large power plants and could save consumers around $30 billion per year on electricity bills. Also, LED lights do not contain mercury like compact fluorescent (CFL) bulbs.

Do LED Bulbs Contain Hazardous Materials?

While LEDs do not contain mercury, a 2010 study published in the journal Environmental Science and Technology found that the presence of other rare and potentially hazardous metals in the LED lights posed a series of problems. Researchers found that both CFL and LED lights had higher resource depletion and toxicity potential than incandescent bulbs. This finding was mostly due to a large number of metals such as aluminum, copper, gold, lead, silver, and zinc.

Following US Federal and California regulations, the research team found that both CFL and LED bulbs should be categorized as hazardous waste items due to the excessive levels of lead leachability and due to the copper, lead, and zinc found in the bulbs. However, currently, LED lights do not have restrictions or regulations on safely and adequately disposing of broken or dead bulbs (though CFLs do, due to their mercury content).

When comparing LED bulbs to their incandescent counterparts, the report concludes that LEDs have a two to three times higher potential environmental impact. These findings, however, can be weighed against the decrease in the number of bulbs sent to landfill, due to their long life.  

Is Bluelight Harmful?

Long term exposure to LED lights in the daylight or cool white color range (4,600-6,500 Kelvins) might also disrupt sleep patterns. Bluelight has a short-wavelength and is considered to be an "aggressive" sort of light that keeps us alert and awake during the day. However, bluelight needs to be balanced during night time hours by other colors of light—particularly red light, which is on the opposite side of the spectrum.

Exposure to large amounts of bluelight during night time can negatively affect our circadian rhythms that govern our sleep habits. A research project by Harvard Medical School found that bluelight can actively suppress melatonin secretion and subsequently shift our circadian rhythms by twice as much as exposure to other types of light on the spectrum. So, choose warmer color LEDs for bedrooms and leisure areas of the home (2,000 to 3,000 Kelvin range).

Another crucial area to consider is the amount of bluelight we are exposed to from other sources like TV and computer screens. There is evidence that the bluelight could be leading to long-term eye problems such as prematurely aging of the eyes, digital eye strain, and even retina damage.