TESTS: Incandescent

Incandescent lamps 1997

Incandescent lamps have not been of much interest to test as it is not a new product on the market. The latest thorough test I’ve been able to find is from the Swedish Consumers’ Association and published in their consumer guide Råd & Rön 3/1997.

The original chart is not published online, I only have a paper copy of it, so I’ve transferred the most relevant data to my own chart. Black numbers are from the actual test, brown are my own, added for comparison and summary. The two left columns represent the nominal output that leading European lamp manufacturer catalogues have stated for that wattage (when used with European line voltage of 230 V), and and the single yellow column shows the difference from measured lumen values in the test.

1997 - Incandescent

Only 7 models were tested, all 60 watt. The article states in no uncertain terms (my emphasis):

“According to the manufacturer standards, a standard 60 watt incandescent lamp should give 730 lumen – measurement of light flow – and burn for 1 000 hours. /…/ A 40 watt lamp gives about 430 lumen and a 75 watt 960 lumen.”

Then it goes on to make a bit of a fuss over the 10 (!) lumen discrepancy of IKEA and General Electric bulbs, but adds that instead they last longer longer. The two lower end bulbs also get a bashing:

“It takes about 15% difference in light flow to be able to perceive it with the naked eye. This means that both Unilight and Ekonomiljus are markedly poorer than the rest.”

Well, no arguing with that. A crappy bulb is a crappy bulb. But then, right in the middle of this article about incandescent bulbs, a CFL propaganda piece is suddenly inserted! And now it gets really absurd…

“CFLs give much more light compared to incandescent bulbs. An 11 watt CFL gives about 600 lumen and a 15 watt almost 900 lumen. So, an 11 watt CFL gives almost as much light as a 60 watt incandescent bulb.”

Huh? If a 60 watt incandescent bulb is not permitted to get away with 620 or even 720 (!) lumen, but when a CFL gives only 600 (at best, in the beginning, at optimal temperature, burning position etc) – then it’s suddenly just fine?? Didn’t the journalist read what s/he just wrote in the previous paragraph? Or was that part inserted afterwards by someone else as that mandatory “CFL info” (= propaganda) which accompanied just about every article on light all through the 1990s and onwards?

Then the article goes on to make more fuss over the fact that the light flow after 750 hours had decreased with a mean of just 6%, as if that was a very high number, when in fact all lamps lose output with age and CFLs much more than other lamps.

No socket problems were found, but half of the Unilite lamps (never heard of that brand) blew the fuses instead of the lamp at the end of life. It was designed for 240 volt but tested at 230 volt, so that may have skewed the test results somewhat. Philips catalogue states: “If the applied voltage differs from the marked voltage, the lightbulb’s properties can be strongly altered, i.e. durability, light flow and used effect (watts).”

There were also big variations in durability between individual bulbs, though several lasted more than twice the promised 1 000 hours.

Incandescent lamps 2004

Another test, made by Consumer Content for Norrköpings TidningarDet lönar sig att välja rätt glödlampa. They tested 7 of the most commonly used 40 watt incandescent bulbs, 4 bulbs of each brand. (No chart, only the article.) 4 lamps of each brand were tested, and the IKEA lamps came out best in test. Translating relevant parts from the article:

[The 40 watt lamp] is useful for most applications in Swedish homes. But the quality varies a lot. /…/ Especially when it comes to life rate. The test winner, General Electric, burned on average 1 722 hours. The poorest performer, Philips, went out after 1 003 hours. 

OK, so now it is considered a ‘quality problem’ that you get 720 extra hours from the GE lamp?? (Will they get fined, as in the good old cartel days?)

The differences between the individual bulb that burned longest, Coop X-tra, 2 277 hours, and Osram, 658 hours is surprisingly big. Even for the lamp industry.

– That there are such big differences between brands and between best and worst lamp indicates problems with internal quality control, says Magnus Frantzell, CEO of Belysningsbranschen [Swedish lighting industry]. 

– This is not acceptable. If marked with 1 000 hours, then all lamps should last that long (…), says Thor Samuelsson, lab engineer at SP, who did the test.

Funny how internal quality  control or ‘truth in advertising’ is never questioned when it comes to substandard CFLs or LEDs.

If differences were big when it came to lamp life, it was the more even when it came to brightness. All brands kept between 426 and 400 lumen (…). Interestingly, four lamps did not fill the requirements, which is at least 415 lumen. Philips and Osram gave the least light. 

– Of course every lamp should live up to standards also with regards to output. (…) But 10-15 lumen either way is impossible to see with the naked eye, says Thor Samuelsson.

So, we’re talking 10-15 lumen! Keep that number in mind while comparing differences in CFLs… And the words “should” and “not acceptable”. No such words were ever used in conjunction with CFL tests, even for 250+ lumen differences!!

Then the article goes on to include the mandatory description on how much money you can save by switching to CFLs, even though these were not included in the test. The whole article seems to be more of a CFL PR article disguised as an incandescent bulb test, i.e. a ‘submarine‘.

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