LED or CFL in enclosed space?
dgb99
1:12p, 04/16/12
dgb99
514 posts, joined 06/03/2002
In my guest bathroom, we have a recessed light above the tub that we use as a 'night light' for the kids. It has a glass lens and a rubber gasket that presumably is intended to minimize moisture from getting in the fixture.

Two issues:
1. For a while, we weren't sure why the light kept burning out. Eventually, we figured out that it was some kind of overheat protection kicking in and the bulb wasn't actually going bad. We put a lower wattage bulb (40 watts maybe?) in there and that seems to have minimized this issue (although it still happens occasionally).
2. Even without the overheating problem, the bulb is still on overnight (and sometimes all day when we forget to turn it off) which means that it burns out fairly fast. I figured this would be a perfect use of a CFL bulb or even an LED bulb. However, when reading the fine print, all the CFLs and LED bulbs indicate that they should not be used in an enclosed fixture. I eventually found an LED light that was rated for 'damp' location and didn't say anything about enclosed spaces on the exterior packaging. Sure enough, when I got home and opened it, the warning about enclosed spaces was written directly on the bulb.

Further reading online indicates that LED lights still give off some pretty significant heat (hence half the structure of the bulb is a heatsink).

Any of y'all use CFLs or LEDs in enclosed fixtures?
spanky
1:47p, 04/16/12
spanky
20649 posts, joined 12/03/2002
What about low voltage halogen? Or is that what you have already? They give off heat, but in my experience last longer than incandescent bulbs in recessed fixtures. Plus, I think the light is whiter and looks a heck of a lot better.

What diameter is the recessed light? There are a lot of retrofit kits out there that can reduce the light size and bulb type.
UnderoosAg
3:26p, 04/16/12
UnderoosAg
7799 posts, joined 03/29/2007
Sounds like the shower/tub light is on its own switch? If that is the case, use the 60/75W lamp (or whatever was in there - provided you don't exceed the rating of the fixture) and swap out the switch for a dimmer. You can dim the 60/75 lamp down to the output of the 40 (or even a bit lower). You should still have enough light to potty by, but dimming extends the life quite a bit. Will also cut down on the heat.

Is this just a potty light, or do you leave it on and crack the door to let light into another room? If it is just for nighttime tinkles, you could also use an occupancy sensor to trigger the light when they walk in and then shut off after a preset time. Option C would be to swap the switch for a switch/controller with a photocell.
UnderoosAg
3:34p, 04/16/12
UnderoosAg
7799 posts, joined 03/29/2007
I have no affiliation with Lutron, other than having used a great deal of their products. They sold me for life when I got a real live person on their tech support line at 2:30am who 1. spoke English and 2. solved my problem. Info below will give you some insight. The Roman numerals are footnotes from the paper.

quote:
Dimming not only saves electricity, but also extends lamp life. At a dimming level of 20%, using a typical 60W light bulb, the bulb life extension will be 4 times iv. A typical incandescent light bulb is rated for 750 hours.


http://www.lutron.com/TechnicalDocumentLibrary/economics%20white%20paper%205-26-10%20A.pdf
Sasappis
3:40p, 04/16/12
Sasappis
18718 posts, joined 08/31/2005
I have a similar light in my shower and have a cfl bulb in there. No problems at all.

I am not sure why it would matter that it is in an closed space.

dgb99
5:27p, 04/16/12
dgb99
514 posts, joined 06/03/2002
Thanks for the dimmer suggestion. This is just a plain A19 socket and a 40W incandescent so I'm not sure if a halogen would work. Don't halogens get extremely hot?

My understanding of the issue with CFLs in enclosed spaces is that the heat from the light will, best case, shorten the life of the ballast. Worst case, it melts the ballast and can be a fire hazard.

I believe it's the same idea for the LEDs although the components are different. I found it hard to believe that either a CFL/LED would get hotter than an incandescent given their marketing as energy-efficient but I came across multiple articles that suggested this was true.

I was just doing some googling/reading that indicated that 'reflector-CFLs' are recommended in enclosed and/or down position fixtures. I had not heard of this type so I'll be looking into it further.
dgb99
5:33p, 04/16/12
dgb99
514 posts, joined 06/03/2002
Hmmm...just found this:
Why do CFL bulbs sometimes smoke when they burn out?
It is normal for some CFL bulbs to smoke a little and even show signs of melted plastic on the ballast at the end of their lives. When CFL bulbs burn out, heat builds up in the ballast (the plastic base of the lamp). As this occurs, the lamp’s safety feature kicks in: the Voltage Dependent Resistor (VDR) is an electronic component that cuts the circuit (like a circuit breaker) in the lamp when the ballast heats up.
In the nanoseconds it takes for the VDR to do its job, both it and the ballast might smoke a little. This is absolutely normal, and part of the lamp’s design. The Underwriter’s Laboratory (UL) certifies CFL bulbs (including their VDRs) that are constructed with plastics that do not pose a fire hazard when overheated.

Maybe the stuff I found that was concerned about fire hazards were referring to this type of smoke/plastic damage.

[This message has been edited by dgb99 (edited 4/16/2012 5:33p).]
EMY92
8:21p, 04/16/12
EMY92
32400 posts, joined 09/13/2000
I don't know, I started switching to CFL's 5 or 6 years ago and have not had one burn out.
Mr. Dubi
10:54p, 04/20/12
Mr. Dubi
4557 posts, joined 01/19/2010
CFL's are way cheaper than LED's and usually dimmer, which may or may not be an issue. You could also try a 130v 25w bulb, it wold be dim, run cool, and last forever.
capn-mac
12:37a, 04/21/12
capn-mac
2232 posts, joined 09/25/2002
All sorts of things here.

First, the box the recessed fixture (aka "can" or "pot") is probably a insulation-contact (IC) rated box. These boxes have a thermocouple in there to prevent a too-large lamp from overheating the box and causing problems for/with insulation in contact with same.

All of those thermocouples are from "low bidder"; some portion are from "least bidder."

Which means that you can read the label stating that nnW maximum, and you install that size only for the faulty thermocouple to kick in, and shut off the lamp.

If that is the case, you're hosed. You just have to down-rate the lamp you use. For instance, for a 60W fixture you'll need to try a 50, 45, or 40W lamp until you find one that works.

Or, follow underoo's excellent suggestion and use a dimmer (just not with a CFL, even a "dimmable" one).

In a bathroom, I like the Lutron "smart" dimmers. Set the light level to the minimum you need, and one tap gets that every time. Two taps is full bright. Three taps fades to off. Easy.

My second preference in dimmers is to use ones with a slider for level, and a toggle for on/off. That way you can set the level to not-break-your-neck and also does-bot-cause-night blindness, and there's no fussing, just throw the switch.

Ok, second issue is CFL. They have problems in ceiling fixtures, for hanging upside down. The lamp designers had to pick an orientation for edison-base CFL. They chose base down. Inside those lamps are circuit cards, cards that replace ballasts and starters. Like everything else manufactured, those components are usually made by low bidder. So, when the heat from the fixture (and the electric bits within) is emitted, it rises away from the sensitive components--but, only if the base is down.

In a recessed ceiling fixture, all the heat passes up into the base of the fixture, and all of the electronics therein. This can shorten lamp life rather starkly.

Both of these conditions can combine, and it's not pretty.
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