Efficient Bulb Test
Test: Bill Whitley, Consumer NZ
Consumer NZ finds the energy saver light bulbs that shine the brightest and last the longest.
Energy-saver light bulbs save you money and also help conserve the country’s energy resources. But which ones give the best light output and keep on switching on? Consumer tested 19 models – and found a wide variation in performance.
Old-style incandescent light bulbs turn 95 percent of the electricity they consume into heat. Only 5 percent is turned into light. With compact fluorescents (CFLs) the figures are about 80 percent heat and 20 percent light. That’s a big difference. So replacing old-style bulbs with CFLs is worthwhile – especially for lights that burn for a long time.
For the test, Consumer wanted to see how the energy-saver bulbs compared with standard bulbs for light output, and how long they lasted after being switched on and off continually. Most of the bulbs tested were CFLs – the best of them had a much higher light output (were much brighter) than the equivalent standard bulb and had a long life as well.
Light output
What Consumer did: They tested 19 energy-saver bulbs:17 CFLs and two halogens.
Most of the CFLs were 20W bulbs, equivalent to a 100W standard bulb. Three were 18W. There was one 23W and one 22W bulb.
The CFLs were mainly spiral-tubes, along with one U-tube and two enclosed globes. The spiral shape has virtually taken over the general-purpose CFL market. It gives a more even distribution of light than the earlier U-tube style, which tends to spray most of the light sideways. The spiral shapes were the best performers in the test.
The two halogen bulbs were 42W bulbs, designed to replace 60W incandescent bulbs. Energy-saver halogens are nowhere near as efficient as a CFL. But they’re 30 percent better than a standard incandescent – and they can be used with a dimmer.
CFL performance: Consumer compared two samples of each of the 17 CFLs against the averaged light output of seven 100W incandescent light bulbs. This averaged “incandescent” figure formed the baseline for the test; and the light output of the energy-saver bulbs is their relative performance against this baseline.
The CFL with the highest light output was the Woolworths Essential, which was 47 percent brighter than the baseline. Next-highest light output came from the Philips Tornado Warm White and the Philips Tornado Dimmable.
Eleven bulbs were brighter than the baseline and eight weren’t.
The worst performers were only 80 and 81 percent of the baseline: these were the Envirolux Create Light and the Edapt Mini Spiral B22 TWES20W.
CFLs that look like a traditional bulb are useful if the bulb is visible and you don’t like the look of the spirals. But both of the globe shapes in the test produced light below the baseline – so use them only for places where you want the look of a traditional bulb.
Two of the CFLs we tested can be used with dimmers: the Philips Tornado Dimmable and the GE Dimmable Warm White. Both performed well and are recommended, but they aren’t cheap. The Philips cost $19.99 and the GE $25.92.
Halogen performance: Consumer tested the two energy-saver halogens separately.
Because these halogens are meant to be equivalent to 60W incandescent bulbs, Consumer compared them (using two samples of each model) against the averaged light output of two different 60W incandescent bulbs.
Both halogens produced only about 75 percent of the light output of a standard 60W bulb.
Long life
What Consumer did: Energy-savers cost more than old-style bulbs, so it’s important they last longer. Consumer put three samples of all the models through a test that switched them on for five minutes and off for five minutes … 6454 times. That’s more than a month of continuous on-off cycling. The bulbs were monitored so we could tell if and when they failed.
Performance: Ten models had no failures during the 6454 on-off cycles (and six of these get Consumer’s recommendation).
The Edapt, E-lite and Signature Range had all their samples fail.
There was some pattern to the failures. Generally, the more expensive big-name brands lasted longer than the lesser-known or home brands. But some big brands had their failures too – most notably one of the Philips and an Osram (see the Table).
The lamps that failed just stopped working – there were no fires, explosions or other undesirable events.
However, on the whole, you can be confident that for the extra cost a good-quality CFL will repay you with a long life.
Both the halogen energy-saver models lasted the full test distance.
Keeping bright
The light output from all fluorescent bulbs usually reduces over their lifetime.
To check this, Consumer put the top three bulbs – the Philips Tornado, Ecobulb, and GE Entice – back into our light-output test rig at the end of the “long life” part of our test. They then compared their light output with the figures obtained when they were new.
In all three cases the light output was within 10 percent of the original values. Not bad after 6454 switching cycles.
Consumer says
- Most CFLs produce at least as much light as the old-style incandescent bulbs they replace. Good CFLs produce substantially more.
- You can be confident that a good-quality CFL will last well in applications where the lamp is frequently switched on and off.
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In most cases, major-brand CFLs last longer than cheaper brands.
Consumer recommends
These bulbs were 19 to 41 percent brighter than a standard 100W incandescent bulb. None failed during the 6454 switching cycles in our “long life” test.
• PHILIPS TORNADO
WARM WHITE
Price: $7.48
• ECOBULB
WARM WHITE
Price: $5.95
• GE
ENTICE
Price: $4.96
• OSRAM
MINITWIST DAYLIGHT
Price: $6.56
• PHILIPS TORNADO
DIMMABLE
Price: $19.99
• GE DIMMABLE
WARM WHITE
Price: $25.92
Other stuff: Consumer New Zealand: www.consumer.org.nz
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