In my home bathroom, one of the light fixtures is on the ceiling. One
incandescent bulb screws in and hangs straight down and the cover is a
glass "bowl" that completely encases the bulb and fixture.
I have never seen a wattage rating on any of the bult in fixtures in
this house. I had been using a 100 watt bulb in this for the last few
years. However, I seem to recall someone posted in here that if the
bulb was completely encased, then it should never be more than a 60
watt bulb. Is that true?
I assume this is a heat issue? But is it more of a bulb life issue or
a safety issue?
It is a heat/fire/safety issue.
Too much heat and no ventilation can cause a lot of heat build-up above the
fixture. Place insulation above the fixture in the attic and it can get
worse! I've seen old wiring above these fixtures where the insulation has
cracked from the heat and there are bare wires in the box above the fixture.
So potential shock hazard and/or fire hazard. How about using a compact
fluorescent which is more cool and also saves energy?
"John Ross" wrote in message
CFLs generally don't take heat as well as incandescents, and many will
cook themselves to death in this fixture. (Enclosed bathroom ceiling
fixture) I would use only ones rated for recessed ceiling fixtures. The
highest output one of these that I know of if the Philips SLS 23-watt
non-dimmable. (The dimmable one was not rated for recessed ceiling
fixtures last time I checked.)
- Don Klipstein ( firstname.lastname@example.org)
Most enclosed fixtures are rated for a maximum of 60-watts and in
absence of any label, I would avoid using a 100-watt lamp. If you
require the light output of a 100-watt lamp and would prefer to stick
to an incandescent source, I might recommend one of the new
high-efficiency incandescents from Philips. The one that provides the
same amount of light as a standard 100-watt incandescent uses just
70-watts; granted, a little more than the 60-watt maximum, but pretty
darn close. In addition to the 30-per cent reduction in energy use
(and corresponding reduction in heat), these lamps last up to four
times longer than a regular A19 incandescent. They're available at
For more information, see:
I haven't personally and likely won't because the fixtures in my home
that use regular A19 lamps have all been converted to CFLs, or where
the lamp is exposed, decorative (flame style) halogens.
To the naked eye, light quality should be pretty much
indistinguishable from a standard soft white incandescent -- if
anything, its slightly higher colour temperature should improve
overall light quality. These lamps utilize an internal halogen
capsule, so the tungsten filament runs a little hotter (2,900K) and,
as a result, the light would appear slightly "whiter" than a standard
soft white incandescent which generally fall closer to 2,700K.
For more information on these lamps, see:
It's not true at all. Depending upon the size of the fixture, a single lamp
fixture will typically take from 60 to 100 watt lamps. I would be more
concerned with the insulation type of the house wiring than the wiring of
the fixture. If your wiring is old rubber covered cloth, I would use the
lowest wattage, preferably CF lamp, you can get. If it's 90 degree
thermoplastic, I'd use whatever max is recommended by the manufacturer. Here
is an example of a typical cheapo 100 watt fixture:
This house was built in 1960. It has the cloth covered Romex with no
ground wire. I don't think there is "rubber" covering it (I think the
cover is an off white color if that helps)? Would the type you are
referring to have been in this time frame?
That would probably be cloth covered Romex with thermoplastic type "TW"
conductors rated at 60 degrees. You don't want to get to much heat on these
conductors, but they won't bake and crumble like cloth covered rubber.
But then you move the wire and the plastic insulation cracks off. The
worst fixtures I ever saw were the old circline fluorescents with the
ballast right under the supply wiring.
Modern fixtures usually come with fiberglass insulation in the canopy to
keep the heat away from the supply wiring. If your fixture doesn't have
any you might want to add some.
Besides the other good reasons posted here, keep in mind the design
criteria for a consumer light fixture will call for a bottom of the
line lamp socket. Typically , these will be rated for 60 W max, and
the heat of larger lamps will deteriorate the socket plastic parts,
the contacts will get limp and you will see it flicker. I have
upgraded some fixtures that needed higher wattage lamps by using
commercial sockets designed for display fixtures. Upgrading
ventilation and wire is also part of the job. HTH
I have replaced the three 60-watt bulbs in my kitchen fixture of the
same type with three 23-watt compact flourescents. You need to wear
sunglasses in there now. It's great.
If I could've fit 40-watters in there, I would have.
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