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April 2, 2022 12:08 PM Subscribe
Why are some lightbulbs not rated for base up operation?
I have a light fixture in our stairwell that currently still has incandescent lightbulbs in. This fixture takes 4 bulbs, 2 that operate base down which are still working, and 2 that operate base up which have burnt out. I have 2 lightbulbs the previous owners of this house left that are the correct wattage, voltage, base type. However, the packaging says they aren't to be used in base up configuration.
1. Why not? Is this a life expectancy thing, and they'll burn out quicker, or is this a safety issue?
2. Can I assume any lightbulbs that aren't specifically labeled as "operate base down to horizontal only" can be used base up without issues?
3. All the search results I came up with when I tried to google this seem to be for LEDs. Is that just because people are switching to LEDs and have more questions about them, or is this a greater or lesser issue with LEDs vs incandescent?
Thanks for any insight, I am not the brightest bulb in the fixture myself.
I have a light fixture in our stairwell that currently still has incandescent lightbulbs in. This fixture takes 4 bulbs, 2 that operate base down which are still working, and 2 that operate base up which have burnt out. I have 2 lightbulbs the previous owners of this house left that are the correct wattage, voltage, base type. However, the packaging says they aren't to be used in base up configuration.
1. Why not? Is this a life expectancy thing, and they'll burn out quicker, or is this a safety issue?
2. Can I assume any lightbulbs that aren't specifically labeled as "operate base down to horizontal only" can be used base up without issues?
3. All the search results I came up with when I tried to google this seem to be for LEDs. Is that just because people are switching to LEDs and have more questions about them, or is this a greater or lesser issue with LEDs vs incandescent?
Thanks for any insight, I am not the brightest bulb in the fixture myself.
I’ve had a compact fluorescent bulb start smoking and melting in a base-up fixture.
posted by songs about trains at 12:42 PM on April 2, 2022 [2 favorites]
posted by songs about trains at 12:42 PM on April 2, 2022 [2 favorites]
Incandescents are obsolete and should be replaced with LEDs whenever possible. They are being phased out to some extent and there will be more of this in the future. LEDs generate very little heat and should be fine in this fixture. I would suggest going to a hardware store and getting a pack of 60W LEDs for $8-10.
posted by Slinga at 2:56 PM on April 2, 2022 [1 favorite]
posted by Slinga at 2:56 PM on April 2, 2022 [1 favorite]
LEDs generate very little heat and should be fine in this fixture.
These are both false statements.
LEDs generate lots of heat, just not as much as incandescent bulbs which literally use "get hot enough to glow" as a method of operation.
For similar reasons, they're also much less tolerant of heat than incandescent bulbs. They're basically electronics. Heat kills.
These problems can be designed around, and plenty of LED bulbs can handle being in enclosed fixtures etc., but generally the cheapest bulbs can't, because they're cheap.
(basically what whatnotever said)
posted by neckro23 at 4:46 PM on April 2, 2022 [4 favorites]
These are both false statements.
LEDs generate lots of heat, just not as much as incandescent bulbs which literally use "get hot enough to glow" as a method of operation.
For similar reasons, they're also much less tolerant of heat than incandescent bulbs. They're basically electronics. Heat kills.
These problems can be designed around, and plenty of LED bulbs can handle being in enclosed fixtures etc., but generally the cheapest bulbs can't, because they're cheap.
(basically what whatnotever said)
posted by neckro23 at 4:46 PM on April 2, 2022 [4 favorites]
Best answer: LED bulbs *do* generate heat. In fact, the earliest LEDs were almost all heatsink, which is why they are not to be used in "base up" config: as it will end up heat-soaking itself.
LEDs have gotten much more efficient, and modern LEDs generally consume roughly 12-15% of the energy of the equivalent incandescent bulb. But that's still quite a bit of heat if you plan to leave this on all the time.
Generally speaking, pay for a name brand like Sylvania or GE should get you better longevity than the generic or Chinese brands. But you *should* look for LED bulbs that are rated for enclosed fixtures. And many vendors will not tell you that. Those are built to dissipate heat better and have also better heat tolerances.
For example, this one is enclosed fixture rated. But it's also expensive as heck.
posted by kschang at 6:44 PM on April 2, 2022 [1 favorite]
LEDs have gotten much more efficient, and modern LEDs generally consume roughly 12-15% of the energy of the equivalent incandescent bulb. But that's still quite a bit of heat if you plan to leave this on all the time.
Generally speaking, pay for a name brand like Sylvania or GE should get you better longevity than the generic or Chinese brands. But you *should* look for LED bulbs that are rated for enclosed fixtures. And many vendors will not tell you that. Those are built to dissipate heat better and have also better heat tolerances.
For example, this one is enclosed fixture rated. But it's also expensive as heck.
posted by kschang at 6:44 PM on April 2, 2022 [1 favorite]
This thread is closed to new comments.
If a bulb doesn't say anything about base up vs base down, it could still have its life shortened by base up operation (if the fixture holds in hot air that way), but if they didn't call that out it's less likely to be an issue.
Incandescent bulbs don't care about heat. In fact, they make light by getting super hot, so they're just sort of used to being really hot.
posted by whatnotever at 12:24 PM on April 2, 2022 [3 favorites]