CFL Ratings for Lamp Fittings?

Can't say for sure, but I suspect it's the manufacturers being cagey (lazy?) - I've found the same with lampshades.

It's probably complete tosh...
It was the heat from the old incandescents that turned the plastic/wiring/lampshade etc brittle, it wasn't to do with the current per se, it was the heat.
OK I know CFLs still get warm, but it's a no contest.
Presumable the various test standards still go by the incandescents as that represents worst case and max fire risk.
Manufacturers probaly then just 'translated' to the 'equivalent' light output (falls off chair laughing as CFLs are all dull as ditch water until they have had 20mins to warm up, and then they aren't that much better).
Del

The answer should be blindingly obvious (pun intended):

• Who on earth would produce a 40W CFL to produce 5x the light output of a 40W incandescent for no power savings, just to use the same fitting (rhetorical question)? Absolute nonsense.

In my limited experience, obviousness does not universally imply correctness.
In this particular case, the reason for asking the question is twofold:

1) As the honourable Mr. Cat* has pointed out, CFLamps don't give out their maximum light initially. In addition, the industry selected "warm white" tungsten lamps as the reference for light output; this means that the chosen tungsten comparison standard gives about 0.7x the luminous efficiency of the (relatively short life) lamps that I used to choose. On top of this, the output is temperature dependent, and it seems as if (even when new) the lamps produce less light under normal domestic conditions than they do in the manufacturers' laboratories. Put together, I find that I need to use about twice the nominal equivalent CFL bulb in order to experience subjectively similar light levels. That would mean replacing my 40W tungsten with 16W low energy. My feeling is that this should be OK with the majority of open (lampshade-style) lighting fittings - but the manufacturers pretty universally say not.

2) In addition, I would rather like to reduce the clutter around the place. Fewer luminaires would help.

So, no longer obvious? (unless you are writing solely from the perspective of a manufacturer who would prefer to sell larger numbers of appliances at low cost to fewer at higher cost).

*Albeit, I've no idea why he mentioned current

The manufacturer is being extremely lazy by not performing some simple temperature tests.

I've got a ceiling fan in my living room with a fixture for 4 bulbs. The bulbs face downward and have trumpet-shaped glass diffusers around them, so the heat from the lamps is captured and rises toward their bases and the highest temperatures should be there. Two of the lamps are 40W incandescent and the other two are equivalent lumens CFLs (8W, I think). The temperatures at the bases of the incandescent lamps is much, much warmer than at the bases of the CFLs.

Most of the heat given off by CFLs goes through their bases, but nevertheless the bases of equivalent lumens incandescent lamps are much hotter.

I see the same sort of thing with bulbs mounted base-down in free air.

The question stands: is the reason CFL lifetime, supplier laziness, or commercial expediency?

Hmmm -- I'm trying to see how CFL lifetime would be affected. Is the heat-sinking ability of a '60 Watt/12 Watt' receptacle that much better than the heat-sinking ability of an '40W/8W' receptacle? [Or is the receptacle rating based on the amperage rating of the power cord?] As I understand it, assuming a typical rate of On/Off actuations the only determining factor in lifetime is the build up of heat in the CFL's electronics. I have trouble imagining that the lifetime of a '60 watt equivalent' CFL would be significantly shorter if used in a receptable intended for 40W instead of 60W.

I lean toward the idea that the manufacturers are either lazy (not wanting to do the long-term temperature tests to see what the difference is), or simply stuck in their obsolete standard that a given receptacle is meant for a given size luminaire, regardless of the actuall wattage consumed.

jut a note, watts is a measure of "heat"....when a CFL is being marketed the claim usually is "the same amount of light as standard bulb but draws less energy to get the same amount of light as a less efficient bulb

The confusion seems to come from two sources.

First, the CFL manufacturers have done lots of base up or base down testing. There are reams of discussions out there if you go looking for them.

All fluorescents operating at a nominal current for that lamp design will want to have a surface temperature of 40°C under normal operation. In a ceiling fixture, the base will typically be above the lamp and heat may accumulate around the base (which may or may not have a ballast attached to it). High output lamps will operate at a higher temperature but all that stuff about wattage is to get you to look at the total operating power being consumed (by design).

The apparent ratio of improvement is 5:1 CFL over incandescent in lumens per watt.

The thing the lighting industry wants you to use to compare is Lumen Output to make your decisions. Unfortunately, they are not there to talk to you as you consider which CFL you want to buy.

I think you will find a better choice by using a comparason of lumens and don't make the mistake of downgrading because the next nearest whole number in lumens is less than the incandescent you are replacing.

If anything, you can put a brighter lamp in place of the old incandescent and still save money, albiet less than the ideal ratio. If you replace a 60 Watt incandescent with a 25 Watt CFL, it will look a little brighter (my ratio is 4:1 when looking at wattage).

This partly sidesteps the issues of concern: that manufacturers give specific CFL ratings for lamp bases and also for shades - and the cfl input power ratings are typically a factor of five down on the tungsten lamp ratings; and, although manufacturers' specify output lumens, subjective visual comparisons (the aspect that matters for me) show these to be significantly optimistic - at least in my environment. For me, the practical multiplier seems to be somewhere between 2.5 and 3 (though it's probably significant that I'm comparing the output with whiter tungsten bulbs)

Its obvious when there is a rating of the CFL for the lamp fittings, people compare it with the overall power consumed bu the bulb.

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