LED Buying Guide
Light emitting diodes, commonly known as LEDs, are becoming more and more widespread in all types of electronics. Their current uses range from small LED flashlights to street signal lights, laptop computers
and giant video billboards.
What a lot of people don't know is that they are starting to find their use in a more common type of lighting application that can be found in nearly every home or office around the world. I am, of course, talking about LED light bulbs.
The fact that you are reading this guide shows that although the idea of using LEDs to replace traditional lighting is starting to become more well known as a greener alternative to energy-efficient lighting (as currently compact fuorescent bulbs are the most widely known), but there are still a lot of people that do not know enough to make an informed decision about how and when to purchase LED light bulbs.
This guide was written as a complete buying guide to give you almost everything you need to know to make an informed decision about buying LED light bulbs and to help you determine whether LED lighting is right for you. This will be a constantly changing document as LED lighting technology is changing so quickly so keep checking back for updates!
Now the pace at which technology is progressing for LEDs right now is astounding as you hear about new developments in LED lighting almost every single week. One of the big pushes for this is not only a significant savings on their electric bill (although that is one of the best reasons to switch), but rather the realization that we all need to rally together and do our part to save the environment. Being green is not just about being "in style" anymore, it has become a practical business model that can help the planet as well as our pocketbooks. People are becoming aware of global warming and becoming more environmentally conscious overall, and are looking for ways to cut their energy consumption. What easier way is there than simply changing a light bulb?
Compact fluorescent light bulbs (also known as CFLs) and LED light bulbs are currently the best alternatives if you want to decrease your energy expenditure in regards to lighting. Unfortunately, LED light bulbs can be more difficult to find and the initial cost can be many times more than a normal incandescent or even CFL. This guide will help you with that decision by providing :
a simple understanding of how LED bulbs work,
what applications they will work best in, and
overview of how LED light bulbs compare in the lighting industry as a whole.
I hope that after reading this, you will be able to see the benefits that LED light bulbs have over other traditional lighting solutions.
What is an LED?
LED Light bulbs are semiconductors, just like a computer chip. When electricity is passed through them, they emit energy in the form of light. They are "doped" or injected with certain chemicals, that determine their light color. LEDs convert the majority of energy passed through them to light, as opposed to incandescent bulbs that produce light as a by-product of being heated thus they can be up to 90% more efficient than traditional household filament bulbs
Types of LED Bulbs
LEDs are directional in nature by the way they're built so any application that requires directional lighting such as track lighting, flood/spotlighting and recessed lighting are a great candidate for using LEDs. This is an example of our PAR 30 LED that is a 5 watt bulb.
For areas where you need light all around you want to look for a diffused bulb. This solves the directional light problem by using a lens at the top of the bulb to disperse the light at wider angles.
MR 16 bulbs can be found in a variety of fixtures. Typically they are only 12 volts so before installation make sure that you are not pluging a 12v bulb into a 110v fixture.
|MR 16 bulbs have three types of pins. Bi pin as above, screw in (edison base) and a twist lock bi pin (GU10).|
How to Determine If LEDs Are Right For You?
Consider the cost savings and other benefits -
Cost - LEDs cost more initially, and there is no doubt that they save you a lot of money in the long run because they last longer and use less energy. Money savings is from using 80% less energy and not having to buy about 25 traditional flood light bulbs. Depending on your state, savings and time for the bulb to pay for itself can vary.
Over 50,000 hours for a typical 7W LED Flood Light replacement bulb (MSRP $79.99) that replaces a 50W Incandescent Flood at 8 hours usage per day:
If you live in Idaho where electricity is the cheapest in the country at 6.3 cents/kWh
You save: $180.46 and the bulb pays for itself in 7.6 years.
In California where the cost of electricity is 14.35 cents/kWh:
You save: $353.54 and the bulb pays for itself in 3.9 years
In Hawaii where the cost of electricity is a whopping 28.27 cents/kWh:
You save: $652.82 and the bulb pays for itself in 2.1 years!
Keep in mind, at 8 hours a day, these bulbs will last about 17 years before they need replacement. You can see the savings really vary so go here to see how your state compares: http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_b.html
If the savings is not as quick as you'd like, there are a few other factors to consider as well that can strengthen the case for switching to LEDs.
Convenience - If you have bulbs in hard to reach places, by replacing them with LED, you dont have to worry about replacing them for a long time. No more driving to the store, buying them, coming back, taking out the ladder, and disposing of old bulbs. In places where you have a lot of bulbs, the time saved can really add up.
Heat If you have a lot of flood lights in a small area, it can really heat up a room significantly. LEDs give off very little heat in comparison. By talking to energy engineers (in California), a good rule of thumb for every kwH of electricity reduced by using LEDs instead of incandescent, you can keep your thermostat higher and reduce your A/C costs by about 20%. I.e. if you save 1000 kWh of electricity per year, you can factor in about an extra 200 kWhs in reduced air conditioning costs as well. Besides the additional money savings, by switching to LED's, your room will be much cooler.
Conscience Do you feel guilty about leaving the light on? Do you have kids that ALWAYS leave the light on? With LEDs they cost a couple of dollars to run a year so you can feel better about having your lights on. A 7W LED bulb run for 8 hours a day for 365 days in California would use about $2.86 a year in electricity compared to $20.44 for a 50W incandescent flood.
LED Bulbs What You Need to Know
Initially when LED bulbs came out with no standards, manufacturers would claim lifetimes of 100,000 hours with no real testing. Since then the standard has been to scale back to 50,000 hours so as not to over-state claims. (Beware of bulbs that are rated at 100,000 hours unless they state specifically WHY they are rated at so high manufacturing process, heat sink materials etc., I would be wary of trusting this rating).
As of May 2009, Many of the manufacturers that we've spoken to, producing their 3rd generation LED bulbs are now starting to be more conservative and rating their bulbs at 35,000 hours, having gotten test results back from 1-2 years of testing. Rated at 35,000 hours, you can rest assured the manufacturer is not overstating their claims. Anything more than 50,000 hours...buyer beware.
The lifetime of an LED lamp is generally considered to be the point where the light output has declined to 70% of its initial output, measured in lumens. So, a 300 lumen LED bulb with a lifespan of 50,000 hours will have 210 lumens at the end of its lifetime. However, the lifetime of a bulb does not mean it is unusable, only that its light output has degraded to a certain point. The LED bulb may continue to be useful for several thousand hours past its stated lifetime. Unlike old-fashioned light bulbs, it is extremely rare for an LED light to simply burn out. Rather, it will gradually fade over time.
As a general rule, you should use warmer light indoors, and whiter light outdoors. A color temperature of 2500-4000 Kelvin works great indoors. You should use a bulb with a color temperature of 5000-7000 Kelvin outdoors, as the whiter light allows your eyes to see better at night. White light in the 5000-7000 Kelvin range is also excellent for display cases, boutiques, artwork, or other settings where you need excellent color rendition.
How to compare the quality of different bulbs -
There are quite a few websites online that you can buy LED bulbs. The problem is "how do you compare one bulb to another?" A quick way to do is to calculate the lumens/watt, or in laymans terms, the total amount of light you get for the amount of electricity you put in. This is done by simply dividing the bulbs wattage by the stated number of lumens.
Anything over 50 lumens/watt is good at the moment. 75 lumens/watt is very good while 100 lumens/watt is excellent. We will be discussing the concept of lumens in a more detailed article in the near future titled: Lumens why you cant use them to compare LEDs to traditional bulbs.
One thing to keep in mind: A halogen flood bulb is more efficient than an incandescent flood and usually costs a little more. Typically for a halogen you get about 1.5x more light for the same wattage. i.e. a 20W halogen bulb gives about the same amount of light as a 30-35W incandescent flood. You can tell if its an incandescent or halogen by reading the packaging of the bulb.
A quick comparison as well to normal light bulbs is as follows:
- 3W High Power LED Bulb - Comparable amount of light as a 25W incandescent flood.
- 9W High Power PAR30 LED Bulb Comparable amount of light to a 50W incandescent flood.
- 18W High Power PAR38 LED Bulb Comparable amount of light to a 100W incandescent flood.
Keep in mind this is just a general comparison - some bulbs may be rated as brighter or dimmer than this. LED bulbs typically have their LED chip or die bought from one place, then assembled elsewhere where labor is cheaper. There are a number of "well known" LED chip manufacturers at the moment. If they're not in this list, chances are they are a smaller company, and are probably less reliable.
From the ones we have experience in testing, and have heard of from the hundreds of manufacturers we've dealt with, the bigger names are:
- Cree (USA),
- Luxeon (USA),
- Nichia (Japan),
- Edison (Taiwan),
- Seoul Semiconductor(Korea) and Epistar (Taiwan)
Here is a typical comparison of lumens direct from a manufacturer in China for a 7W LED bulb using different dies/chips:
You can see that Cree is by far the brightest. However, there are multiple factors, besides the LED chip that determine the brightness of an LED bulb including the power supply and optics (the lens or lenses that are used to diffuse the light).
One surpising example we've seen and tested is one bulb that used 9 x 3W Cree LEDs (27 Watts), while another used 6 x 3W Epistar LED(18 Watts). The lens being used in the Cree LED bulb was poor, so the light pattern was uneven and the bulb was about 30% dimmer than the the Epistar bulb, even though it used about 50% more energy.
Also notice that Warm White is always less bright than Cool White. This is because in simple terms, in order to get the warm white color, the LED is coated with yellow phosphor to make it "warmer" and thus reduces the light output. Cool White LED's have "less" of a coating.
Typically you'll see bulbs in the 30 to 70 degree range. These are spotlights and will give a much more focused light than traditional incandescent flood lights. The best way to tell is to see an actual picture of the bulb in action since this measurement can vary widely between manufacturers. Even though youll hear comparable to a 50W flood, the LED light will in the majority of cases be more focused than a floodlight. Again the best way to tell is if the site shows you a side-by-side comparison.
If youre looking for a more dispersed light like a traditional bulb, look for a 120 degree beam angle or larger.
If you're going to spend $30-100 dollars on an LED bulb make sure your investment is protected. Sure you can buy off auction sites and get them on the cheap with no warranty, and a knockoff LED chip or you can spend the money and get a good bulb with a solid warranty. Dont settle for anything less than a two year warranty since the bulbs should last at least 4 years at 24 hours usage per day (35,000 hours).
Start Using LEDs Now!
LEDs arent a good alternative for all bulbs in a business. Depending on the situation, they make sense in some places more than others. The more people who adopt LEDs, the quicker prices will come down. Theres no doubt that as prices come down, and efficiency/light output of the bulbs increase, in a couple of years every light bulb in the world will be an LED Light bulb and CFLs and incandescent will be a thing of the past. The initial investment may be a little hard to swallow, but in the long run, youll be doing your part for the environment and your wallet and making the world a cleaner, greener, cooler place to live one bulb at a time for generations to come.