Light bulb question

"John Carter"

** The makers of CFLs recommend you do NOT use them in enclosed fittings.

More so if the CFL is of a high power rating, and if the fitting is exposed to sunlight or mounted on the ceiling.

Problem is, incandescent lamps can operate happily at temps that would make any CFL fail in a few minutes.

..... Phil

It'll die an early death. All of the CF bulbs that I've ever seen have stipulated that they be used in an area of free air flow, and when I've neglected to heed that advice they've died.

They're cheaply made, with mediocre parts; the ones we've put in fixtures with air flow have lasted well, the others -- died.

--
www.wescottdesign.com

Not necessarily. The 100W bulb is 100W of heat... or like 99W. So just because it is equivalent to such a light bulb just means that it probably is still 24W of heat. Hence enclosing that heat may or may not cause some serious problems. It will still be somewhat hot as it's dissipating about

1/4 the heat. 25W is pretty significant... enough that you can easily burn yourself(if the heat is localized at least).

is

n

Not so Jon. Phil and Tim are correct _but_ I have seen a few CFLs that stated they _were_ suitable for use in an enclosed space - and upside down. Read the packages carefully.

G=B2

I think the technology keeps improving. My wife has them in an enclosed fixture in the kitchen and they've been surviving for years now - right over the electric range too.

I take apart the bad ones and salvage the ferrites - it is amazing how much the semiconductors have shrunk over the years - all the parts shrink, but now they have something the size of a TO92 where they used to have TO220's

CFLs cooking themselves is a common problem.

Besides not being able to withstand high temperatures as well as incandescents can, CFLs are more efficient at producing convected and conducted heat than incandescents. Incandescents produce a fair amount of infrared, which usually mostly escapes the fixture. A 100 watt incandescent probably causes about 2-2.5 times as much heating of a fixture as a 27 watt CFL does.

Once, I tried a 42 watt CFL and a 60 watt incandescent in an enclosed fixture, and the fixture got very slightly hotter with the 42 watt CFL than with the 60 watt incandescent.

There is a 23 watt CFL rated for recessed ceiling fixtures and probably OK in enclosed fixtures: Philips 23-watt non-dimmable SLS ("triple arch") "Marathon".

- Don Klipstein ( snipped-for-privacy@misty.com)

Ikea sells FCL's that are enclosed in a plastic globe. I'd say that kills the airflow.

I've got em' in the bathroom and they do fine since it's not a constant light situation in there.

"T"

** It's not the temp of the glass tubes that matters - it's the temp INSIDE the plastic base.

Cos that is where all the electronics is !!

** Shame that is the one place where CFLs are least likely to be satisfactory.

1. Most CFLs are not moisture proof and will fail if allowed to get damp inside.
2. Constant cycling dramatically shortens lifespan.
3. Most CFLs are slow to give full light output, the opposite of what one needs in a bathroom.

..... Phil

DE

damp

at one

"> ** Shame that is the one place where CFLs are least likely to be

p

Gotta agree, I put in a whole bunch of 'vanity' CFL's around the bathroom mirror. That was a few years ago, they are slowly dying and I'm replacing them with the original incandescent. (I assume the death is caused my the humid environs of the bathroom.)

live and learn, George H.

I have mostly good experience with both CFLs and regular fluoreascents in bathrooms. My biggest problem was ones with glow switch starters and 60 Hz inductor ballasts lasting roughly 1500 operating hours, due to this type of starting rougher than other starting methods and short on time per start. Even with gentler starting methods used by electronic ballasts, life is likely to be less than full rated. The next biggest issue appears to me to be color rendering of skin, makeup and clothing.

I have heard of the humidity issue before, but my experience with bathroom and outdoor CFL usage leads me to believe it is a minor one.

- Don Klipstein ( snipped-for-privacy@misty.com)

"Don Klipstein = Stupid Old Fart "

** Regular fluoros are simply NOT the issue.

** CFLs do not have them. ** Most CFLs are available in " warm white" colour temp - which gives good skin tones. ** Not humidity - but CONDENSATION from steam in a bathroom.

This shows the insides of a typical CFL.

Many CLFs have ventilation holes that allow moisture inside.

Switching 240 volts AC ( =340 volts DC) onto a wet PCB = BANG.

Message to Don:

-------------------

Fact is, those who know NOTHING about a problem ought to have the sense to shut the f*ck up.

Don has no sense at all.

..... Phil

"PL" types such as F13TT, F13DTT and F26DTT do.

Colors are still not quite the same. I find skin is shown more pinkish under a CFL than under an incandescent of the same overall color. All CFLs with the usual triphosphor formulation claim a color rendering index of 82.

I have used choke ballasted and electronic-ballasted CFLs in my bathroom since 1991 without this problem occurring even once.

- Don Klipstein ( snipped-for-privacy@misty.com)