@mattalter - All LED bulbs put out heat through the big metal heatsink that is usually integrated into the base of the bulb. I have a an 11 Watt TCP bulb (60 Watt incandescent equivalent) right in front of me and the base is too hot to touch when the bulb is on at full brightness. If your bulb is dimmed down, the heatsink will not be as hot.
Incandescent bulbs dissipate the heat throughout the whole bulb surface. LED concentrates the heat where it connects to power. The total heat is less but more concentrated. The big challenge when ramping up LED wattage is how to dissipate this concentrated heat.
TCP bulbs are UL listed, so they most likely adhere to certain safety standards that outline the maximum temperature an external surface may reach. Although that temperature might be hotter than what you or I might like, it may very well be acceptable according to the standard. The heat is generated out of the back of the LED(s) inside the bulb. If the heat is not dissipated through the heat sink, it will cause the LED to degrade and eventually fail. Unfortunately, all the electronics are surrounded by all that heat, but their engineers must have done reliability tests to ensure the bulb will still work satisfactorily under the worst conditions. That might also be why there is a warning on the bulb that says not to put the bulb into a totally enclosed fixture. Without air circulation, the heat will have no where to go and eventually cause components to fail in the bulb.
@jaypatel512, hot LED bulbs shouldn’t be viewed as bad. As long as the device has an agency certification like UL, CSA, or ETL, they should be safe to operate when used as instructed.
There are LED replacement fixtures for High Intensity Discharge lamps (HID) that have massive heat sinks due to the amount of heat the LED generates, but it is necessary to prolong the life of the product.
When properly heat-sinked, an LED lighting device is more likely to fail due to the electronic components in the LED driver being overstressed than the LED itself failing.
This discussion is all very subjective. How much heat sinking, how the heat is being dissipated. If you have one of those devices that measure power usage (they’re accurate to the .01 amp), just measure how much current it’s drawing compared to the 11 W TCP bulb. If they both draw the same amount, then they’re both producing pretty much the same amount of “heat”, as long as the light output is similar.
@wolfram, I used a Kill-A-Watt meter to measure the 11 Watt TCP bulb and the meter says the TCP bulb is drawing .13 Amps at 129.6 V @59.9 Hz with a Power Factor of .82. In total, 14 Watts consumed by the TCP bulb.
A typical 60 Watt incandescent bulb will consume, surprise, around 60 Watts of power of which the majority is lost as heat.
The TCP bulb does not consume anywhere near 60 Watts of power, the difference being 46 Watts!
The 11 Watt TCP bulb will not produce as much heat as a 60 Watt incandescent bulb because LEDs are more efficient at producing light in comparison to a tungsten filament. In other words, for the same amount of light produced by the incandescent bulb, the TCP bulb doesn’t need as much power. Yes, the heat sink on the TCP bulb will get hot, but not nearly as hot as that 60 Watt bulb. I can still touch the surface of the TCP bulb heatsink without burning myself, but only briefly. I refuse to touch the surface of a 60 Watt bulb for any amount of time.
my concern is not related to any of the temps mentioned, my concern is what the bulb base TOUCHES and where this heat dissipates. I see a lot of ceiling fixtures, “professionally wired” antiques, and enclosed bulbs where the air temp is not a problem but the sockets, insulators, socket wire, and odd metal alloys now appearing might see temperatures way hotter than an incandescent, and over a longer period as well. any long term thoughts?
I have the concern too. I just pulled a 9.8 W bulb from a fixture in an old victorian home where the wires were burned due to the heat of the LED base - there could have been a fire. These particular LED (KolourOne Intertek/SATCO) appear to be a fire hazard, and should be recalled. The light fixtures, at the point where the bulb is screwed into the fixture were never designed to dissipate this type of heat. They were always aircooled since the heat was due to the filaments that are near the surface of the large end of the bulb, which is far from the attachment point. There is no heat conductivity in many or most of the lamp bases in use today, so the heat is not conducted away. It just builds up. This particular LED failed - presumably due to the heat. FYI. Many UL rated devices are not necessarily tested, they can be self certified by the manufacturer.