I once saw a "bankers' lamp" style desk lamp rated for 60 watt tubular "T10" bulbs produce a slight burning odor and have wire insulation slightly char with a 60 watt bulb. It was plenty fine and dandy with a 40 watt one.
I suspect the fixture was manufactured and tested in a country where the prevailing line voltage is 230V, or most thermal testing was done with a
230V bulb or otherwise vacuum-containing bulb. I suspect most 60 watt
230V bulbs of that style have a vacuum - most bulbs drawing less than about 20-25 watts per visibly-apparent inch of filament length have a vacuum. But the 120V 60 watt version of that bulb is gas filled. (Gas allows higher filament temperature, but conducts heat from the filament to the surface of the bulb). So I am guessing that the 120V version runs hotter than the 230V version. It did indeed run quite hot. Meawhile, the USA-usual 40-watt version has a vacuum and runs cool.
Just to make the point excruciatingly clear, at the risk of beating this already-dead horse to death: even though the ratings have little to do with the amount of current drawn by the bulb, I would never attempt to exceed those ratings, say by putting a 75-watt bulb in a fixture labeled for 60 watts. In fact, as pointed out by your example, it would be better to err on the side of caution, especially if in doubt. If the fixture says 100 watts, use a 75 watt bulb, maximum.
Make that mid or upper 30's or so. I did once measure temperatures on a fixture (with a non-contact thermometer) and got the fixture slightly hotter with a 42 watt (150 watt incandescent equivalent) CFL than with a
60 watt incandescent. Incandescents produce a lot of infrared - much to most of which escapes the fixture and becomes heat where it is absorbed - usually mostly all over the room it is in. CFLs produce conducted/convected heat more than anything else, and after that visible light.
If rated honestly, about 200-250.
Make that 42 watts. A 42 watt CFL typically produces 2600 lumens. A
150 watt 120V 750-hour incandescent of "Big 3" brand and with CC-8 style filament (axial coiled-coil) typically produces 2980 lumens, maybe more like 2900 even for "soft white".
As I said above, when I compared fixture heating by a 42 watt CFL and by a 60 watt incandescent, the fixture got slightly hotter with the 42 watt CFL.
Next lower common wattage I have seen is 30 watts, and I see those at Lowes. Home Depot may have 30 waters also. My experience is that those outshine 100 watt incandescents rated 1750 lumens by a small amount when young and at favorable temperature. I suspect they fade to close to
1670-1750 lumens after 2 or 3 thousand operating hours. I suspect they easily overheat in downlights and small enclosed fixtures.
Next lower common wattage of CFLs after that is 26 watts - usually rated to produce 1750 lumens - when in a favorable range of temperature and young. They typically produce something like 10% less after aging 2 or 3 thousand hours. 100 watt 120V incandescents of "Big 3" brand and CC-8 style filament are typically rated to produce 1670-1750 lumens.
Next lower common wattage of CFLs is 23 watts - usually rated to produce
1600 lumens. That is when in a favorable temperature range and in first few hundred hours of operation. I would say more like mid-1400's after aging 2-3 thousand hours and in a favorable temperature range - I would call that "roughly halfway from 75 watt equivalent to 100 watt equivalent". 23 watts is the highest wattage of CFLs that appears to me to have "fairly good" survival in downlights and enclosed fixtures. Philips "triple arch" "Marathon"/"SLS" 23 watt non-dimmable is the highest wattage and brightest CFL that I am aware of that is actually rated to take the heat of recessed ceiling fixtures. The dimmable 23 watt and the 25 watt versions of this one are not rated for this as of last time I checked.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.