Does anyone know whether it is ok/good to use compact flourescents in recessed cans?…I know there is more heat generated in the can. And do they make a compact flourescent that is dimmable?
thanks,
ecw
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The compact units have their own ballast attached and since they are typically rated at 15 or 20 watts and replace a 60 or 75 watt rated bulb they should not be a problem...
I do not know of any units which work with a dimmer unit.
There are CFLs that claim to be dimmable. I have not tried them with a dimmer, but I have used them with electronic motion sensors and they worked in that application.
The dimmables are lousy. They only dim to 50% or so before going out, and they flicker badly. This is an area that still needs work.The concern with CFLs in cans is that the heat production is concentrated in the ballast, and the ballast may overheat due to lack of ventillation. This used to be a problem for some designs, but modern CFLs have efficient electronic ballasts that seem to do OK. At the very least we've had them in enclosed globes in our family room for 6 months with no sign of problems, and that's got to be a more difficult scenario than a can.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
I have a ceilingfull of Panasonics.
No problems other than they are expensive, but I have cases of spares so I'm okay for awhile.
No knowledge of any dimmable though.
Joe H
I know there is more heat generated in the can
?? My CFLs in cans generate much LESS heat than incandescents or halogens. I have a very bright 11x17 kitchen with six cans x 13 watts each - sweet!
I stand corrected on heat generated...I meant to say that because the recessed can is enclosed, the heat is trapped with less circulation of air....anyway, I am going to try the cans.Thanks.
I've had some of my CFL burn out in a few months, but the other seem to have the long life. My 6" ICF cans are in the kitchen.This application will weed out the weaklings!
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
My CFLs i bought from Costco just last and last. I changed out the ones in the kitchen bec they didn't seem as bright as they'd once been three years ago, but they don't fail.
Either that's a comment on how good they are or how little time i spend in the kitchen.
The some CFL manufacturs say that the cans allow heat to build up and it might shorten the live of the bulb. But if it does it does not appear to be by a large amount.
My experience has been with standard CFL bulbs with a white baffel.
Here are some dmimable ones. Note that some come in R-30 and R-40 styles.
http://www.energyfederation.org/consumer/default.php/cPath/2050_25_44_169
Here are reflector CFL's of all sizes and types.
http://www.energyfederation.org/consumer/default.php/cPath/2050_25_44_171
Note the Fiet R30 is a High Heat version designed for use in cans.
http://www.energyfederation.org/consumer/default.php/cPath/2050_25_44_171_1363
You can also get reflectors to add on to Panasonic capusul and globe bulbs. Don't know if they will fit a can or not.
http://www.energyfederation.org/consumer/default.php/cPath/2050_902
http://www.energyfederation.org/consumer/default.php/cPath/2050_25_44_168
http://www.energyfederation.org/consumer/default.php/cPath/2050_25_44_1619
And you can get a conversion kit for can lights to use the plugin flourscents. Particullary helpful you need to go flourscent for energy codes. They won't accept edison base CFL's as you can replace them with incandenscents. And they are dimmable.
http://www.energyfederation.org/consumer/default.php/cPath/2050_25_174_510
Thanks for the very helpful info on the energy federation site.
Thank you for taking the time to put up those links. Mike
Trust in God, but row away from the rocks.
When I was researching for our recessed lights (two years ago) there was only one manufacturer, Philips, that dared to put the words "recessed lighting" in their list of tolerated installations. The cans retain a lot of heat and many bulbs would fail early. Now I see that they've made even further progress. This might be exactly what you need:
http://www.nam.lighting.philips.com/us/consumer/marathon/display.php?mode=3
I don't know what they cost or where you can get them. HD sells other Phillips products, maybe they can get these.
Scott.
Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”
My experience with CFL's is that they last longer than incandescents if you burn them base down to horizontal. Heat rises, and base up in an enclosed fixture you trap enough heat to kill them. In track and cans, my CFL's didn't last as long as incandescents. Nowhere near as much heat as incandescents, but that's trumped by their vulnerability to it. So, I use incandescents in any base up fixture.
There's also the spectral spike thing, but we've discussed that here before.
-- J.S.
I've had somewhat the same experience. My mother has round hanging globe lights in her kitchen and I installed standard Home Depot issue CFLs in them only to have them last no longer than the previous 100 watt incandescents.
Interesting, as my experience has been so different. Is it the brand of bulb, do you suppose?
must be the off shore buyer beware bulbs / lamps..
brands matter..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
Brand of bulb, ambient temperature, and how much air circulates thru the fixture would be the factors. Are you in a cold climate? Are there holes for air to circulate thru your fixtures?
I don't know actual figures, but my guess would be that most any CFL would last fine if the temperature in the electronics package stays under 75, and would die quickly if it spent most of its working life at temps over 100.
The other thing I've noticed is that the white plastic of the base turns increasingly yellow/brownish when the CFL has spent some time being hot.
-- J.S.
Like I said, we've had CFLs operating for 6 months with no trouble in approx 8-inch closed globes. And we've had CFLs in our entry way fixtures for years -- these are approx 10" closed globes. I'd expect that these tend to run in the neighborhood of 100F.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
Take a look at the plastic on the old ones, and let us know if it's turning yellow.
-- J.S.
Some of the real old ones. But the color of the plastic isn't a functional issue.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
It does seem to be a good indicator of heat history, though.
-- J.S.
Well I only look at them when I replace them, and that isn't very often, so I don't have much of an impression of the color.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
I have ICF cans, thoroughly surrounded with insulation. The 'holes' in the can are what they are, nothing additional. Cold in winter, but pretty darn hot in summer, over 90* much of the summer. I just unscrewed a bulb to check the plastic, too - quite yellow. The only place i've managed to burn out the bulbs, come to think, is the one bulb left on continually in the laundry room where the cats box is, in the basement and very cool. I have to replace it about once a year.I wonder if your bulb-death problems are due to something other than heat?
I kinda doubt it given that CFL's in the same house with similar amounts of on time seem to have their life expectancy strongly correlated with operating temperature. I even flipped the wall fixture in the guest bath to gain the advantage of base down operation for the CFL's.
-- J.S.
Some of the early CFLs, IIRC, were not supposed to be operated base-up, because of the heat problem. But I haven't seen this restriction on newer ones, and we've had them in our entryway lights for probably 5 years, base up.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
Our experience has been similar. We put them in all of our ceiling mount lights (which the bulb package says is OK) and while they last a bit longer than the incandescents, they sure don't make it anywhere near the 7 years that Phillips promises.
Remember, the 7-year figure would be for "typical" use, and they usually figure "typical" as about 3 hours/day.I'm guessing we've had CFLs in the entryway in place for about 5 years, and I had to replace one of them for the first time about 6 months ago. I don't recall ever replacing the other one.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
TJK raised a point we should have thought of sooner -- how many watts are your long lasting CFL's? Perhaps low wattage plus your cooler climate there in MN account for your getting better results than I do in LA with 23 watt CFL's.
-- J.S.
These are the 60-75W "equivalent" units for the most part. I forget the stated actual wattage.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
We've been using the cheapie multi-pack HD CFLs for several years, and find them to be reliable and produce good quality light.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
There are recessed-can fixtures designed for CFL, and they usually have a separate ballast and mount the bulbs horizontally. The small circuit board used in the electronic ballast of mass-market CFL lamps is designed to be as cheap as possible. Cheap capacitors, cheap transistors, cheap diodes -- cheap. Heat it up to 180F for a few hours a day and the life of those cheap parts will be cut drastically. That is why 23W & larger CFLs won't last very long mounted with the base up in sealed (IC) fixtures. The 13W CFLs seem to do OK because they don't heat up as much in a 5" or 6" can.
The only dimmable CFLs I've found to work well are made by Phillips. But even those can have problems with low-cost dimmer switches where either the bulb, the dimmer, or both start humming loudly.
If you plan to use any of the X-10 home automation gadgets, CFLs will cause a lot of headaches. The (cheap) electronic balasts put out tremendous electrical noise that jams the control signals to/from many X-10 devices. Yes you can buy filters, but when all of the bulbs are CFL, the whole thing can get crazy and expensive.
I'm hoping this CFL thing is just a passing fad, and eventually we will see LED bulbs at reasonable prices.