Home Depot is selling a nice and easy to install LED retrofit for can lights. We decided to try one as we have lots of can lights that would benefit from an efficient retrofit. This page gives a rundown on the installation and the results.
Bottom line is that we are very pleased with it so far.
This is the Home Depot listing for the light... Cost is $40 -- kind of steep, but see the payback calculations below. Note that the package picture above says 9.5 watts instead of 10.5 watts, but I think that its the same light.
- 575 lumen output with 10.5 watt power consumption
- 2700 Kelvin color temperature (warm), and 92% color accuracy.
- 20 year life
- Instant on
In our case, the light went in quite easily.
Basically, the new light has 3 spring clips that stick out as shown in the picture below. When you slide the light up into the old can, the spring clips engage the walls of the old can, and hold the new light in place. The clips are designed such that when you rotate the fixture CCW, the clips rotate inward and release the light so that it can be removed.
The step by step:
We like the new light. It gives off plenty of light. The pattern is wide. The light color is warm and pleasant to work in. There is no startup delay.
We have not tried the new lamp with a dimmer -- a few people reported flickering with their dimmer, while most had no problem.
There were 117 reviews on the Home Depot site. The overall score was nearly 5 out of 5 stars. There were many 5 star reviews -- comments like: "Fantastic Light", "Blows away CFLs", "Awesome". The only negatives I saw in a quick review were: 1) did not work well with some dimmers, 2) does not fit all cans.
The packaging claims over "more than $200" lifetime saving. Lets see how it works out for us.
If the light is on 6 hours a day (as the one we replaced is), and it replaces a 65 watt incandescent, and you pay 10 cents a KWH for power, and you use the bulb 350 days a year -- then the yearly electricity saving is:
Year Saving = (65 watts - 10.5 watts)*(6 hr/day)*(350 days/year)*($0.1 /KWH)*(1 KWH/1000 watt-hrs) = $11.45 per year
Maybe another $1+ per year for bulb replacements (depending on what you use now).
A total of about $13 per year saving.
So, the payback on the $40 initial price is about 3 years -- beats the stock market.
The CO2 emissions saving per year at the US average 1.5 lbs CO2 per KWH is 170 lbs per year. -- 3500 lbs CO2 over a 20 year life of the bulb.
In addition to the electricity saving, there can be a saving in heating fuel. If you use this as an opportunity to seal up and insulate the can fixtures, I think the saving in heating fuel could be significant -- especially if you live in a climate like ours. As a very very rough estimate:
If you have a can light that is not insulated above (as cans often are), and this is the equivalent of 1 sqft of R1 insulated area, and you insulate over the can to R40, and you use propane fuel at $2 per gallon, and you live in SW Montana with 8100 Heating Degree Days, then the Insulation Upgrade Calculator shows a saving of $5.50 a year in heating fuel.
People living in less of a winter wonderland than we do
would see less saving.
People in cooling climates should see a saving on the AC bill both because the bulbs generate less heat and there is less loss of conditioned air into the attic.
BUT THAT's NOT ALL -- IF YOU CALL NOW, WE WILL THROW IN AN INFILATRATION SAVING!!!
I was not able to find a good method to estimate the infiltration/exfiltration saving. But, some good sources report that the major contributor to exfiltration is air leaking from the living space into the attic. The cold outside air and warm inside air creates a stack effect with a small pressure differential that wants to move air from the living space into the attic. This results in new cold air being pulled into the house, which has to be heated. The can lights in our 1996 home have quite a bit of open crack length -- just looking at one, I'd say about 25 inches of nearly 1/8 inch crack area. So, you have open area for air to flow through and you have a pressure differential trying top push air through the opening -- it stands to reason that there will be significant heat loss.
In our case, I've already replaced most of the can light bulbs with CFLs, so the saving is not nearly as large as the change from incandescent to LEDs shown above.
In the end, the nicest features (to me) are that if the life claim is anywhere near correct, I'll never have to change these lights again. And, the light color is very pleasant.
January 16, 2012