Energy saving light bulbs offer dim future | Hacker News Reader

Energy saving light bulbs offer dim future

telegraph.co.uk

14 pointsd0mine17 comments

More garbage science.

You can not measure lux when you are so close to the bulb, and lux is not the correct measurement for light bulbs anyway, lumens is.

Lumens: total light produced by bulb in all directions.

Lux: amount of light hitting a sensor, adjusted proportionally based on size (area) of sensor. (It's actually light per area.)

If you put the sensor close to the bulb most of the light from the bulb will bypass the sensor.

An incandescent is basically a point source of light, so putting the sensor close works fine.

Florescent is not, the light output comes from a large area. For the real world, unless you need a spotlight, this makes no difference, since you are illuminating an entire room. But if you try to measure with a small sensor you will underestimate the light output.

11W low-energy CFL produced only 58 per cent of the illumination of an "equivalent" 60W bulb

So use two and you get over twice as much light for about 1/3 the energy consumption.

> So use two and you get over twice as much light

Over 15% more, 2x58 = 116 not >200.

Or get a 22W CFL. The issue here is the false claims of equivalence between 60W incandescent and 11W CFL.

Yes, you're correct. Thanks.

The really weird thing is that a normal, useful technology, which produces no bad externalities (no extra pollution, etc.) is being banned outright, rather than being taxed - instead of this why didn't they just slowly raise taxes on incandescent bulbs, to force people to notice? And instead of that, it'd be even better just to raise taxes on energy itself - that way people could choose where to cut energy costs, and not be forced to cut it specifically from the light bulb portion of their total energy cost.

Also, the fact that people haven't stopped using incandescent bulbs naturally just shows that electricity is still ridiculously cheap.

I don't agree that people still using incandescent bulbs is evidence that electricity is ridiculously cheap. Electricity bills aren't itemised so only when the total becomes painful will people consider the cost of their individual appliances. Bulbs are priced individually and so people are hesitant to switch to an option, CFLs, which they may perceive to be the more expensive.

I had six daylight-balanced mini fluorescent bulbs in my living room and I had to remove three of them because they were blindingly bright. These are 8w bulbs.

Too bad EU is on 220v. I'd ship you guys incandescents from the US.

You could actually, if the sockets are the same. The light will be twice as bright, and the bulb will last probably 1/4 of the normal lifespan. The energy efficiency will be higher.

The hotter the filament, the shorter the life, but the better the energy efficiency (also slightly less reddish light). Light bulbs have a filament length tuned typically to 2000 hours.

TV studio lights are often tuned to last just 50 hours, but they are way more energy efficient. But not necessarily dollar efficient.

No, they burn really bright for about 1-2 seconds and blow out. Voice of experience.

Experience trumps theory every time.

Several things: 1. Ok, 15w or 11w - not a big deal, the difference in energy savings less than 10%. Irrelevant worry. 2. But real issue is spectral content of light, it is not same, and frankly, I find flourescent light very unpleasant.

You might prefer daylight-balanced tubes then. Alternatively, just hold out for LEDs which offer a wide range of color temperatures.

Protip: if you absolutely cannot live without the incandescent look, get the bulbs you want at a photography store and put a dimmer into the power line (because they're typically 200w+). You might get some sticker shock with your next electricity bill, though.

The color temperature is not the issue in how fluorescents look. The color issue is that there are a only a few phosphors in the bulb, and so all of the light coming out is at just a few discrete wavelengths. An incandescent produces a smooth combination of all wavelengths in the visible range. The light from a fluorescent looks like the right color on a white surface, but many dyes reflect specific wavelengths of light. This means that colors under even good fluorescent lights look different than under incandescent or daylight. LEDs have the exact same problems.

Check out Viva-Lite -lamps. They produce "Full spectrum light", which is quite frankly just awesome.

I'm not affiliated with Viva-Lite, just a happy user. Having 26W model here, it's maybe bit cold (5500 K), but still reproduces colors accurately.

edit: At least my lamp has quite long warm-up time. I haven't actually measured it, but I think its far longer than 10 minutes used in the article. Thats a major downside in ESL.

edit2: I actually forgot to add the link: http://www.viva-lite.com/

> In our test, we used a simple lamp with a light metre placed half a metre away,

A light metre is 1 / 299 792 458 or 3.33 x 10e-11 seconds

Dear Daily Telegraph,

When an energy saving light-bulb is on, can you see?

Good, now be quiet.

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