Energy efficient bulbs?

Apparently "energy efficient" CFL bulbs aren't as helpful at reducing energy as generally thought. For homes located in colder climates, old-style light bulbs don't just provide light, they help heat the homes. This element is actually surprisingly significant. Most CFL light bulbs claim to reduce energy consumption by 75%. While they do indeed tend to use this much less electricity than incandescent bulbs, the more important figure should account for the loss of heat. After adjusting for this factor, the average savings in energy with CFL bulbs when used indoors is about 20%, not 75%. In fact, in some northern villages that rely on expensive shipped oil to generate electricity, CFL bulbs actually result in more energy consumption. However, people who live in a persistently hot climate and make heavy use of air conditioners can rest assured that they're saving a lot of energy by switching to newer bulbs.

I personally do not use any CFL bulbs.

They're actually phasing out incandescent lamps here and it's getting quite difficult to find them nowadays. I for one won't miss the bloody things. I swear one of the fuckers blew up somewhere in the house at least once a month. I don't think I've had to replace one CFL since I started using them, and the "doesn't warm the house" is another big plus.

Why wouldn't you use CFL lamps assuming you didn't know about the heat thing before hand?

Mainly because my rent covers electricity and because I'm responsible for buying my own bulbs.

I started converting to CFL's a few years before the government "saw the light" and while being more expensive they'll typically lasts 8-10 times as long as a cheap incandescent globe - assuming the latter isn't permanently switched on. Bulk packs of 4 or 10 tend to be best value for money so I suggest you do the maths and shop around.
So far as using incandescent globes as supplementary heating is concerned, that's a valid point, but without decent reflectors most of that radiant energy is doing little more than warming the ceiling.

Heat is one issue, surely, but it's not the real reason why CFL are less than ideal.

Check out this article: it's a bit lengthy, but it issues the main problem, which is the power factor of CFL lamps, an issue which is seldom brought up, and even less CFL bulbs address in some way.

In layman's terms, "power factor" is the quality of power delivered across the electric grid: the smoother and more sinewave-like and in-phase current and voltage are, the higher the quality. On the other hand, a device that draws current in "pulses" and causes current to lag over voltage (or viceversa) has poor power factor. The issue is that more power has to be generated than is really consumed at the final load, the rest goes just to charge/discharge inductors and capacitances across the whole grid. More power= higher current. And higher current = greater resistive heat losses along the way.

In practice, a 25W CFL will actually require that the *power plant* is able to deliver at least 50W of apparent power, or else it will malfunction. So far, home consumers do not have to pay for this extra power, but the utility company has to produce it. Corporate/industrial users on the other hand are either required to pay a premium, or install power-factor correction equipment on their end.

In general, only expensive, high quality CFLs have power factor correction or any mention of it on their box, while bulk ones are, in general, pretty nasty with their internal electronics.

BTW, that same issue plagues switching power supplies, too, which are too starting to replace the good old iron core transformers.

The "heat from light bulbs" argument is only valid with an inefficient heating system, e.g. direct electric heating. Heat pumps can have an electricity-to-heat efficiency of 400%.

That said, there are other reasons not to use CFLs.

Fredrik said:

That said, there are other reasons not to use CFLs.

They contain mercury and other chemicals, for starters, which makes them more difficult to dispose of.

However, my household has switched over to CFLs.

They also have a failure rate which is much higher than claimed, and much more hazardous failure modes. So far, not a single CFL I owned reached the phase where the tube produced too little light to be useful.

They all died catastrophically because of failures in the electronics, usually popped capacitors or carbonized transistors, usually well within the first year or use. No wonder cheap CFLs usually use recycled good tubes from other discarded CFLs...

Oh and BTW, the world's most long lived light bulb is incandescent...

Maes said:

They also have a failure rate which is much higher than claimed, and much more hazardous failure modes. So far, not a single CFL I owned reached the phase where the tube produced too little light to be useful.

Heh, that reminds me. In a box of CFLs my family bought, there was one that didn't work, and at first I couldn't figure out why. That was until my father examined it and noticed that there was a small part of the tube that was completely empty.

Not to mention that CFLs also have mercury in them and your pretty much fucked if you broke them just in case if you didn't know.

Nightmare Doom said:

Not to mention that CFLs also have mercury in them and your pretty much fucked if you broke them just in case if you didn't know.

Earlier I said:

They contain mercury and other chemicals, for starters, which makes them more difficult to dispose of.

:/

Snarboo said:

Heh, that reminds me. In a box of CFLs my family bought, there was one that didn't work, and at first I couldn't figure out why. That was until my father examined it and noticed that there was a small part of the tube that was completely empty.

You mean "empty" as in it had no white phosphor coating on a portion of the tube? That's normal, and shouldn't hinder operation (at most you'll have some UV leaking...)

"Empty" as in it was missing some mercury gas? No way you can test for that save for powering the tube from a known good ballast and seeing what happens.

And...yeah, it's supposed to be an empty tube filled with transparent gas and only two electrodes at two of its extremities. If it's 2- or 3-tube it may also have one or two "empty" glass pathways between individual tubes.

Energy-efficient bulbs have a "warm-up" time where they're not so efficient. Energy consumption for incandescent bulbs is a simple linear measure of the time they're on; it's not so simple for others. Lamps that are frequently turned on for short duration then turned off are actually better off being incandescent bulbs. Lamps that stays on for long periods of time should be energy-efficient.

Gez said:

Lamps that are frequently turned on for short duration then turned off are actually better off being incandescent bulbs. Lamps that stays on for long periods of time should be energy-efficient.

Heh, try explaining that to the dummies that use them in staircase lighting....

Maes said:

You mean "empty" as in it had no white phosphor coating on a portion of the tube? That's normal, and shouldn't hinder operation (at most you'll have some UV leaking...)

I'm guessing that was it. If that doesn't effect operation, then I don't know why it didn't work.

Snarboo said:

I'm guessing that was it. If that doesn't effect operation, then I don't know why it didn't work.

Probably busted electronics, especially if you got no hint of warming up or at least some smell/sound clue. I've got quite a few duds myself. On the other hand, these lamps are the joy of the DIYer, as they can be opened up and scavenged for electronic components (power transistors and inductors are among the most expensive stuff you can extract from them).

Fredrik said:

The "heat from light bulbs" argument is only valid with an inefficient heating system, e.g. direct electric heating. Heat pumps can have an electricity-to-heat efficiency of 400%.

That, and the fact that the heat one does *not* get directly from electricity, is almost always more efficiently produced. It takes double to triple the amount of oil/gas/coal to produce a given amount of heat under the form of electricity, than burning the oil/gas/coal in-situ (in your stove, fireplace, boiler etc.)

Even that initial argument about how not getting as much heat from the bulbs results in spending more to get the same amount of heat from even a dedicated electric heater....smells like BS, it would be like saying that the light bulb is better at heating than the heater is.

That being said, if you work e.g. on a cold desk, an incandescent bulb will surely make it more cosy, if it has a proper reflector.

Unless you're an industrial user, why give a shit about power factor correction? I've been tempted on several occasions to plug in a huge inductor just to screw with the power company. Then again, I don't have any superconductors, so I'd still be paying for the resistance of the coil's wire.

If there's a mass household switching to CFL *and* to switched power supplies, then power factor will become a consideration for utility companies, mostly because they didn't bill domestic users for apparent power until now, and due to power quality issues.

My main objections with CFLs is that they give off florescent light as opposed to the more natural light given off by "old-fashioned" argon lights. Everything looks off-color under their light which just bothers me. Not to mention it messes with me when I'm doing something like painting minis. I still buy the argon bulbs, though I don't actually have to pay for electricity so heh.

I tried using CFLs in my room until I remembered that they work all funny in sockets where the switches can dim. They would buzz and flicker a lot unless I had the switch in a specific position. It was really weird but it gave me headaches, so I stopped using them in the room and put them in somewhere else.

Danarchy said:

My main objections with CFLs is that they give off florescent light as opposed to the more natural light given off by "old-fashioned" argon lights. Everything looks off-color under their light which just bothers me. Not to mention it messes with me when I'm doing something like painting minis. I still buy the argon bulbs, though I don't actually have to pay for electricity so heh.

I agree. The light from the older bulbs has more of a yellow sun-like tone to them while the newer bulbs are almost like a pure white. Also, as mentioned above, they don't seem to work with dimmer switches which sucks big time.

I'm not sure if it was the bulb or the lamp, but one CFL I had would always make a buzzing/humming sound, and they also do take a few minutes to "warm up". And as Danarchy said, one of my biggest problems with them is that they have a much more restricted/unnatural light spectrum, which may have negative effects on our vision and mood.

The heating factor is interesting though, if you're trying to keep the place cool. Also I wouldn't be opposed to using them in places where they'd almost always be on, such as more public or industrial places. But other than that, for the average household I would stick with incandescent bulbs.

Maes said:

Check out this article

A very interesting read, gonna have something to talk about at work. Definitely going to try my own triac dimmer with a CFL now.

I have a few "energy efficient" light bulbs in my house. I don't like them and will probably replace them with proper bulbs.

Why? Main reason: because they don't give off enough light. The whole point of a light bulb is to light things up. If they don't do that properly, what's the point?

"Energy efficient" bulbs take a while to warm up (as has already been said) and whilst they are warming, they don't give out their maximum light. As they get older, they seem to take longer to warm up. Also, even when they are warm, the light they give off is distinctly gloomy compared to a traditional bulb of the rating they are supposed to replace. Again, as they get older, their maximum brightness seems to decrease (versus a traditional bulb which may dim slightly but eventually will just go rather than get duller and duller). Also, I find the quality of the light less pleasing than traditional bulbs too. So, on its primary function of providing light, with respect to a number of criteria, an "energy efficient" bulb doesn't compare well with a traditional bulb.

They may have a longer life, but they are significantly more expensive and I can buy a fair number of traditional bulbs for the cost of an "energy efficient" bulb (although there have been various schemes to give away free ones).

Finally, they are big and ugly. OK, so a traditional bulb isn't the prettiest thing on the planet, but the "energy efficient" ones are definitely uglier IMO. Also, because of their increased size, they are less versatile - fitting into less shades and fittings than the smaller incandescent bulbs. Indeed, in my house, I have very few "bog standard" shaped/sized bulbs due to having a variety of fancy light fittings of different types. So, I could only put "energy efficient" ones in the few traditional fittings that I have anyway.

Ask me about "energy efficient" light bulbs. :P

Enjay said:

Ask me about "energy efficient" light bulbs. :P

To your very good points, I'd add that manufacturing such a bulb can't be more energy efficient than manufacturing a traditional glass bulb: several different types of materials, complex electronics, stringent limitations on ambient conditions and power installation (to the point that some CFL bulbs clearly state not to install more than 4 or 5 on the same luminaire), and many, many things that can fail prematurely.

About the stated light output...I've found it to be fairly true if compared to opaque incandescent lamps. E.g. typical 21W CFL claims to give off 1200 lumen, and say that this is like a 100W bulb...well...not exactly. A clear 100 W bulb gives more than that, nearly 1500. An opaque one will be closer to 1200 lumen, so the comparison will be more reasonable.

Color rendering...yup, it sucks. If it wasn't important, and efficiency was all that mattered, then we'd all be using yellow or pink sodium lamps!

They are not even a good solution if you need high levels of uniform lighting in an room: traditional FL tubes do a better job than both incandescent and CFL in lighting up a large workplace and the such.

About longevity again...I had some drop-shaped bulbs in my bathroom that blackened and burned out very quickly, let's say 1 every 2 months. I noticed that they were installed with a downwards 45 degree angle, and that caused heavy blackening near their bottoms. I replaced them with round incandescents, and those are still going.

Also, the most long-standing bulbs in my house are some 10+ yo low-voltage halogens: didn't have to replace a single one of those. I doubt any FL or CFL lamp can last that long.

I don't know what you guys are talking about with regards to color. I have a bunch of n:vision "daylight" CFLs throughout my apartment, and they look exactly like the name implies, daylight.

Enjay said:
Finally, they are big and ugly. OK, so a traditional bulb isn't the prettiest thing on the planet, but the "energy efficient" ones are definitely uglier IMO. Also, because of their increased size, they are less versatile - fitting into less shades and fittings than the smaller incandescent bulbs.

Some are small, now, though. I have one that looks like a squat and tight corkscrew or a compressed spring that occupies the same space as a regular bulb.

Yeah, it seems like most of the people here who are against CFLs are talking about the ones that were available a decade ago.

The fact that CFLs have an inferior color rendering index is, well...a fact, although it's not as bad as it may sound. Having a CRI in the 70-90% range is much, much better than the 5% of a yellow sodium street lamp ;-)

And yeah, there are CFLs with pleasant light tones out there, however certain colors such as "Cool White" or "Daylight White" have the disadvantage of being perceived as less luminous by the human eye, and so they make the CFL bulbs appear even dimmer. E.g. 1200 lumen from a 2700K CFL >> 1200 lumen from a 6500K CFL.

The fact that I can still tell a difference between a CFL and an incandescent lamp is enough proof for me that CFLs are a sorry replacement for General-purpose lighting.