Oct 28 2019
Have to admit I got all excited over a light bulb. Well, to be more accurate, I got all excited over the price of a light bulb. Had a few minutes to spare and stopped at one of my favorite big-box home stores to pick up a tube of caulking. Strolling down the lighting isle, the sale tags were catching my eye. And then, there it was - big green tag pronouncing 50% off and it was pointing at a 7.5 watt, LED light bulb. I nearly dropped my caulk.
I had not yet had a LED light bulb grace my home, but with that sale tag, one was going to be gracing today. This light bulb would cost $18 without the sale, but today, bless the big-box, it was going to be mine for $9.98. I would finally get to witness and review the newest, energy efficient bulb available.
You can see by the sales slip, that the LED cost $9.98 and the Alex ultra clear caulk cost $4.17. So what's the $6.00 charge at the top? That is a six pack of 13watt CFL bulbs. Yes, they were on sale too. So, let's do the math and compare the cost of LED bulb with the CFL.
One 7.5 watt LED bulb cost me $9.98 - equivalent to 40 watt incandescent.
One 13 watt CFL bulb, $1.00 - equivalent to 60 watt incandescent.
Considering the initial expense, the CFL is the choice of every wallet in the country.
How long will a LED bulb last?
Right below the LED in the picture is the pronouncement - Long Lasting, 25,000 long is 25,000 hours? 24 hours in a day, do some dividing, and you get 1000 days, divide again, 2.74 years. So, right there on the package, it is telling us that this light bulb will brighten our lives, burning continuously for 2.74 years. Compare this to the 10,000 hours of a CFL and the 1,000 hours of an incandescent and the LED is the hours winner.
Look at the lower left corner of the picture, see where it says, 7.5 W - 40 W and indicates that 1 LED bulb equals 25 incandescent bulbs? That means in energy use, measured in watts, a 7.5 watt LED equals the energy use of a 40 watt incandescent bulb. It is also indicating that the lifetime of one LED equals the lifetime of 25 incandescent bulbs. Most of your incandescent bulbs have a lifetime of 1000 hours compared to the 25,000 hours of the LED.
How bright is a 7.5 watt LED bulb?
Looking again at the picture, the package gives the information that this bulb gives off 450 lumen's. Of course, lumen's is how we measure the power of light perceived by the human eye. The more the lumen's, the more bright the light. Of course!
7.5 watt ( 40 watt ) LED produces 450 lumen's.
13 watt ( 60 watt ) CFL produces about 900 lumen's.
60 watt incandescent, soft white, 840 lumen's.
When selecting a light bulb, what you might want to consider is the number of lumen's in comparison to the watts - lumen's per watt - energy efficiency would be increased with lots of lumen's and little watts. The other thing to consider with lumen's is how much light does your application call for. Is the light bulb being used in the home office where you need more light, or in the ceiling fan with five other bulbs where you do not need the light bulb to be so bright.
Estimated energy cost
This picture provides some of the basic information all in one place and is found on the outside of the package. It has listed again the lumen's, but expands the information concerning energy cost in the next section down. Yearly operating costs based on 3 hours per day and 11 cents per kilowatt hour:
LED, 7.5 watts, 90 cents per year.
This compares to:
CFL, 13 watts, $1.57 per year.
Incandescent 60 watt, $7.23
What is light appearance?
That brings us to Light Appearance. See along the bottom where it has a line and it says warm on the left and cool on the right? And underneath the line, over on the left side is a small arrow with the figure 3000 K. This small graph gives us an indication of the color of the light that is produced.
This business of light being colored and referring to light color as warm and cool reminds me of referring to a drink as being dry, basically it makes little sense. What we might need to remember concerning light color is this:
The K behind the number ( 3000 K ) refers to temperature on the Kelvin scale.
Color temperatures over 5000 K are cool colors and are usually bluish white in color.
Lower color temperatures ( 2,700 - 3000 K ) are called warm colors and are usually yellowish white through red.
A warmer or lower color temperature is often used in public areas and promotes relaxation.
A cooler or higher color temperature is often used to enhance concentration and focus as in an office setting.
I have often heard people say that they do not like CFL lights because the color is wrong, they're too yellowish or dingy. Well, they weren't kidding, the light can be a slightly different color - some folks are simply more sensitive to the color of light than others. By paying attention to the information on the bulb container, you may be able to adjust the color of the light your purchasing by noticing the warm and cool scale indicating the kelvin temperature of the light.
What is a soft white light bulb?
A soft white light bulb is a bulb at 3000 K or less.
Bright white is a bulb around 3,500 K
Cool white then is about 4,000 K
and bulbs referred to daylight are 5,000 K and higher
If we take the container and look at the top end we see an indication that this bulb is considered Soft white because it is 3000 K along the Light Appearance graph or spectrum. If a person wanted a whiter or brighter colored light, they would need to select a bulb that is near the 5000 K spectrum.
For my needs, I will pay attention to the watts - how bright the light is, and I will pay attention to the cost. Light color does not concern me and I pay little attention to the soft, whites, brights or anything named kelvin.
In all the reading I was doing on the outside of this LED light package, I was looking for an indication of whether or not this light bulb was recommended for use inside an enclosed light fixture - like the one on my kitchen ceiling. You know, the kind that takes two light bulbs and you cover the light with a glass case. I had to wait until I actually purchased the light and opened the package. There, written on the bulb itself, was the hard to read proclamation that this bulb was not to be used in total enclosed luminaries. I always like it when simply instructions use big fancy words. Maybe the term luminaires is better for the french customers or something.
In most cases, when a light bulb is not recommended for an enclosed fixture, it is because heat can build up, become entrapped in the enclosure, and shorten the life of the bulb. Heat is an enemy of all light bulbs. Luckily, the bulb is designed to burn out and cool off before fire danger.
The glass part of an LED bulb stays cool and makes it easy to handle even after it has been on for an extended time. However, the base part of the LED gets hot and is uncomfortable to touch. Having ventilation around a light bulb, any light bulb, so heat can dissipate is important to it's life span.
I though it very interesting that this information was only written on the bulb itself and did not appear along with the rest of the information on the package. I think they are trying to pull a fast one on us!
Here's what I am going to do concerning LED light bulbs.
Keep my eye pealed for sales. I wish I had purchased more 7.5 watt bulbs for $9.98.
Every chance I get, remove enclosed light fixtures including recessed and canned lights.
When sales allow, change all my CFL's to LED's.
I put the LED in the lamp in the family room. It is brighter than the similar sized CFL it replaced and seems to brighten the whole room just a little more. I am looking forward to getting additional LED's and trying them in other locations. It's nice to know, every indication points to the probability, that I will not have to exchange that luminar again in my lifetime.
Thanks for stopping by, hope this article has been enlightening, come back soon, but I won't leave the luminar on for you.