We typically have been buying light bulbs based on how much energy they consume (Watts), regardless of light emitted (Lumens). All that began to change with the advent of different types of light bulbs, such as CFL, halogen, LED, etc., since they consume different amounts of energy to produce the same amount of light.
Lumens measure how much light you are getting from a bulb, regardless of type and regardless of energy consumed. This equalizes all bulbs and types for comparison. More lumens means brighter light.
Another measurement that is not well understood is Kelvin. It is a scale of measurement for the color a light produces. The higher the Kelvin (K) number, the cooler the light appears. Most bulbs will be in the 2,500K to 6,500K range, with 2,500 being the warmest and 6,500 the coolest. Kelvin is usually ignored except for specific lighting circumstances. The 2,700K to 3,000K range is warm and inviting, 3,500K casts a neutral light, 4,100K casts a cool and bright light, 5,500K to 6,500K range is closest to daylight.
To compare brightness of typical old style bulbs, here are a few examples:
Replace a 100-watt incandescent bulb with a bulb that gives you about 1600 lumens,
Replace a 75W bulb with a bulb that gives you about 1100 lumens,
Replace a 60W bulb with a bulb that gives you about 800 lumens,
Replace a 40W bulb with a bulb that gives you about 450 lumens.
Sixty watt bulbs used to be the standard as they offered the best compromise of minimum required light and cheaper cost. Now that energy cost has been so greatly reduced, 1100 lumen lights are becoming the standard minimum. Brighter lights make it easier to see and make everything look better, especially when trying to sell your house.
Showing posts with label CFL. Show all posts
Showing posts with label CFL. Show all posts
Apr 8, 2016
May 1, 2015
LED, Lumen, CFL, and CRI
We are now faced with many choices
for light bulbs. Prices vary widely for not much difference in
light. Here a few things to know about the choices.
First, lumens are the new watts. Watts are power and lumens are light. An old incandescent 60 watts is about 800 lumens of light. The wattage does not matter and most of the comparisons regarding electricity costs are measured over years, so not very consequential in a monthly or annual budget. A 60W incandescent lamp may push 800 lumens, while a CFL only needs 15W and an LED only needs 10W to produce the same lumens. (A 10W incandescent is a night light.) The thing to remember is how bright you want your light to be. Look at lumens below to get the correct amount of light from your new bulbs.
incandescent bulb
watts - lumens
60 - 800
75 - 1,100
100 - 1,600
150 - 2,600
Heat might not seem important, but with a number of lights burning, it adds up, especially during the summer. One heat test - halogen bulb, a type of incandescent bulb, measured 327 degrees. A Cree LED downlight was measured 107 degrees and a Philips Par38 CFL measured 167 degrees. LEDs produce 3.4 btu's/hour, compared to 85 for incandescent bulbs.
Bugs don't fly toward many LEDs, because bugs are attracted to ultraviolet light and most LEDs do not give off this type of light.
LED are rated to last 50,000 hours, while CFLs are rated for 10,000 hours and incandescents are rated for about 1,000 hours.
LED bulbs turn on as quickly as incandescent bulbs and faster than CFLs. LEDs produce roughly the same amount of useful light, but much of that light is focused in one direction. LEDs typically shine up, rather than in all directions like incandescent bulbs. Newer LEDs can be omnidirectional, look for that word on the package.
Some LEDs do not dim well and tend to buzz or sputter when the dimming is at half. Check the package to make sure the bulb will work with a dimmer.
A new term to further confuse us is CRI, because of the number of different light types. It did not make any difference in the past as all lights were the same. CRI is color rendering index. The higher the CRI, the better the color rendering ability. Light sources with a CRI of 90 or higher are excellent at color rendering and should be used for tasks requiring the most accurate color discrimination. CRI is independent of color temperature, but I won't even go there. Too much information.
When considering lighting, I usually think of CFL as meaning 'crap for light'. They take longer to turn on (it typically takes 30 seconds to 3 minutes to complete), need more energy to turn on, contain mercury, may leak UV radiation, do not work well in cold conditions, produce artificial fluorescent color, and are less efficient than LEDs.
Although initial price is still much higher, the price of LEDs is coming down quickly. LEDs are down to $4.97 at Home Depot, a far cry from the old $20 they used to cost. Bottom Line, let your old bulbs burn out before you rush out to buy new "energy savers" the price will likely be cheaper when you are ready to replace. Also, higher lumens are brighter and higher CRI provides better color discrimination.
First, lumens are the new watts. Watts are power and lumens are light. An old incandescent 60 watts is about 800 lumens of light. The wattage does not matter and most of the comparisons regarding electricity costs are measured over years, so not very consequential in a monthly or annual budget. A 60W incandescent lamp may push 800 lumens, while a CFL only needs 15W and an LED only needs 10W to produce the same lumens. (A 10W incandescent is a night light.) The thing to remember is how bright you want your light to be. Look at lumens below to get the correct amount of light from your new bulbs.
incandescent bulb
watts - lumens
60 - 800
75 - 1,100
100 - 1,600
150 - 2,600
Heat might not seem important, but with a number of lights burning, it adds up, especially during the summer. One heat test - halogen bulb, a type of incandescent bulb, measured 327 degrees. A Cree LED downlight was measured 107 degrees and a Philips Par38 CFL measured 167 degrees. LEDs produce 3.4 btu's/hour, compared to 85 for incandescent bulbs.
Bugs don't fly toward many LEDs, because bugs are attracted to ultraviolet light and most LEDs do not give off this type of light.
LED are rated to last 50,000 hours, while CFLs are rated for 10,000 hours and incandescents are rated for about 1,000 hours.
LED bulbs turn on as quickly as incandescent bulbs and faster than CFLs. LEDs produce roughly the same amount of useful light, but much of that light is focused in one direction. LEDs typically shine up, rather than in all directions like incandescent bulbs. Newer LEDs can be omnidirectional, look for that word on the package.
Some LEDs do not dim well and tend to buzz or sputter when the dimming is at half. Check the package to make sure the bulb will work with a dimmer.
A new term to further confuse us is CRI, because of the number of different light types. It did not make any difference in the past as all lights were the same. CRI is color rendering index. The higher the CRI, the better the color rendering ability. Light sources with a CRI of 90 or higher are excellent at color rendering and should be used for tasks requiring the most accurate color discrimination. CRI is independent of color temperature, but I won't even go there. Too much information.
When considering lighting, I usually think of CFL as meaning 'crap for light'. They take longer to turn on (it typically takes 30 seconds to 3 minutes to complete), need more energy to turn on, contain mercury, may leak UV radiation, do not work well in cold conditions, produce artificial fluorescent color, and are less efficient than LEDs.
Although initial price is still much higher, the price of LEDs is coming down quickly. LEDs are down to $4.97 at Home Depot, a far cry from the old $20 they used to cost. Bottom Line, let your old bulbs burn out before you rush out to buy new "energy savers" the price will likely be cheaper when you are ready to replace. Also, higher lumens are brighter and higher CRI provides better color discrimination.
Nov 8, 2013
Laser Headlights are Coming
BMW is working on laser
(Light Amplification by Stimulated Emission of Radiation)
headlights to be introduced on selected 2014 models. They promise
to be much better than the relatively recent LED headlights. The
laser lights will put out more light and use two-thirds the power
of LEDs, which use one fourth the power of ordinary headlights.
They are also much more efficient and brighter than the current
Xenon headlights used on some cars. In addition, they are just 10
square micrometers and 1/10,000th the size of a
1-square-millimeter LED.
The inventor of the headlights says Laser lighting may even do away with household LED and CFL lighting before either takes off. These new Laser lights are also ideal for businesses, signage, and projectors used in movie theaters, as well as smartphone projectors. The Laser lights are different than you might think of a laser beam. These lights are diffused blue beams and reconstituted to a white specific width for use. There is no danger of an accident creating a beam that could be harmful to the naked eye.
Einstein came up with the theoretical foundation for lasers in 1917 and they were first demonstrated in 1947. They have been in use since then for various applications, but almost always as a concentrated beam.
It took from 1879, when the incandescent light began until a few years ago for radical change, now we have another whole new generation of lighting in about five years. In spite of the hype from manufacturers, it will likely be a few more years before we can buy one for our homes.
The inventor of the headlights says Laser lighting may even do away with household LED and CFL lighting before either takes off. These new Laser lights are also ideal for businesses, signage, and projectors used in movie theaters, as well as smartphone projectors. The Laser lights are different than you might think of a laser beam. These lights are diffused blue beams and reconstituted to a white specific width for use. There is no danger of an accident creating a beam that could be harmful to the naked eye.
Einstein came up with the theoretical foundation for lasers in 1917 and they were first demonstrated in 1947. They have been in use since then for various applications, but almost always as a concentrated beam.
It took from 1879, when the incandescent light began until a few years ago for radical change, now we have another whole new generation of lighting in about five years. In spite of the hype from manufacturers, it will likely be a few more years before we can buy one for our homes.
Sep 16, 2011
CFL Light Bulb Facts
CFLs burn out rapidly when they’re not allowed to rest at least 15 minutes between being cycled off and on. They overheat and fail if they are used in recessed ceiling canisters
CFL floodlights in outdoor motion-sensor systems is bad because of how fast the bulbs expire when they have to flick on and off so quickly. CFLs contain mercury, enough that the Environmental Protection Agency’s cleanup instructions for a broken bulb run three pages and start with a warning to open windows and evacuate people and pets.
CFL floodlights in outdoor motion-sensor systems is bad because of how fast the bulbs expire when they have to flick on and off so quickly. CFLs contain mercury, enough that the Environmental Protection Agency’s cleanup instructions for a broken bulb run three pages and start with a warning to open windows and evacuate people and pets.
May 4, 2011
Some Illuminating Thoughts
On Jan. 1, 2012, 100-watt incandescent bulbs will start disappearing from store shelves.The front of the new bulb labels will list energy cost and lumens, which can vary widely even for bulbs consuming the same amount of energy or wattage. Lumens already appear on bulb packaging, but we often overlook the fine print.
The back will list the bulb's expected life span, energy consumption and its "light appearance," or color, which is measured on a temperature scale known as Kelvin (K). Lower Kelvin numbers mean the light is more yellow; higher Kelvin numbers mean it's whiter or bluer. The traditional incandescent, which gives off a warm, soft and almost yellowish light, has a temperature of about 2,700 to 3,000K — similar to most halogens. LEDs' temperatures range from 3,300 to 5,000K while CFLs can be quite warm (2,700K), neutral or cold (6,500K).
For kitchens and work spaces, where a brighter and whiter light is desired, look for bulbs marked 3,500 to 4,100K. For a cooler, bluish light akin to daylight, good for reading, look for bulbs with 5,000 to 6,500K.
For CFLs, the back label also notes that the bulbs "contain mercury" which, in high enough doses, can cause tremors, mood swings, headaches and insomnia. (CFLs have, on average, 4 milligrams of mercury, while older thermometers have about 500 milligrams.) No mercury is released unless the bulb breaks. Besides being expensive, I have tried them in my ceiling fans and about one in four burns out within a few months. The new label lists a government website for tips on how to clean up broken pieces and dispose of the bulbs. This is very scary stuff.
Here is a link to a Youtube explaining the new CFL bulbs LINK This Texas congressman is not happy. If these bulbs are really that good, we would have already bought them and they would not have to be forced on us.
The back will list the bulb's expected life span, energy consumption and its "light appearance," or color, which is measured on a temperature scale known as Kelvin (K). Lower Kelvin numbers mean the light is more yellow; higher Kelvin numbers mean it's whiter or bluer. The traditional incandescent, which gives off a warm, soft and almost yellowish light, has a temperature of about 2,700 to 3,000K — similar to most halogens. LEDs' temperatures range from 3,300 to 5,000K while CFLs can be quite warm (2,700K), neutral or cold (6,500K).
For kitchens and work spaces, where a brighter and whiter light is desired, look for bulbs marked 3,500 to 4,100K. For a cooler, bluish light akin to daylight, good for reading, look for bulbs with 5,000 to 6,500K.
For CFLs, the back label also notes that the bulbs "contain mercury" which, in high enough doses, can cause tremors, mood swings, headaches and insomnia. (CFLs have, on average, 4 milligrams of mercury, while older thermometers have about 500 milligrams.) No mercury is released unless the bulb breaks. Besides being expensive, I have tried them in my ceiling fans and about one in four burns out within a few months. The new label lists a government website for tips on how to clean up broken pieces and dispose of the bulbs. This is very scary stuff.
Here is a link to a Youtube explaining the new CFL bulbs LINK This Texas congressman is not happy. If these bulbs are really that good, we would have already bought them and they would not have to be forced on us.
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