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Posted

Hi . I was always under the impression that low energy light bulbs do not work with dimmer switches but someone told me they do.

Before I change all my lights is any one using these?

Thanks.

Posted

In general, you are correct, low energy bulbs (Compact Fluorescent Lamps) don't work correctly with dimmers.

Look for the ones marked as "dimmable" for your fittings with dimmers, more expensive but they do work, I've seen them in HomePro :o

Posted

Looked at them in Home Pro and they were 415 Baht each. As my house has 23 bulbs on dimmers I decided against it. Bought the kids bedside lights and put low energy bulbs in them.

Posted
Looked at them in Home Pro and they were 415 Baht each. As my house has 23 bulbs on dimmers I decided against it. Bought the kids bedside lights and put low energy bulbs in them.

OUCH!

You may still score and save energy by determining which lamps actually get dimmed to variable levels and installing dimmable CFLs in them. The others, replace the dimmers with conventional switches and install CFLs of appropriate size for the light level you desire. Depends how green you want to be :o

These dimmable units dim very efficiently, they really do use half the energy when they're at half brightness and the tubes last longer too.

I've not looked for them in Thailand (might start now) but you can also obtain dimmable ballasts with replaceable tubes, you just change the tube when it fails (cheaper).

EDIT Westinghouse make a dimmer that will dim a non-dimmable CFL, http://www.retex.com/resources/westinghouse.htm dunno if it's available in Thailand and you can bet it's not cheap but it is an alternative :D

Posted

Don't know about costs but aren't LED's very efficient, last almost forever....and dimmable?

Of course you would have to retool the wiring 'cause they're not 220V.

Posted
Don't know about costs but aren't LED's very efficient, last almost forever....and dimmable?

Of course you would have to retool the wiring 'cause they're not 220V.

Yup, nowadays you can get them 12/24/110/220V in different packaging (replacement for halogen spotlight bulbs, normal light bulbs etc). Few suppliers in TH and crazy prices, but there are cheap and good ones available in China. A couple of more importers and they'll be cheaper here too.

Posted
Don't know about costs but aren't LED's very efficient, last almost forever....and dimmable?

Of course you would have to retool the wiring 'cause they're not 220V.

Yup, nowadays you can get them 12/24/110/220V in different packaging (replacement for halogen spotlight bulbs, normal light bulbs etc). Few suppliers in TH and crazy prices, but there are cheap and good ones available in China. A couple of more importers and they'll be cheaper here too.

Scary pricing, online purchase 220V 5W LED spots, US$20 each (bulk 10 off pricing) including postage.

Not found anything other than spots or halogen replacements.

Dimmable CFLs are looking more attractive.

Posted

Since the level of electrical expertise is so high on this forum, I'll tender a feeble question from an un-educated person (me):

Do rheostat dimmer switches actually reduce the amount of electricity used? I thought I read somewhere that all the rheostat did was keep the current from reaching the bulb, but actually consumed the extra current by converting it partially to heat? Now that I try to write that, it sounds totally implausible, but yet I'm sure I read something close to that. What's the real story?

Posted

"rheostat"

A rheostat is a variable resistor that changes the voltage to the light bulb. As you change the voltage, the light will get brigher or dimmer. The rheostat will get warm-to-hot, depending upon the amount of voltage you're dropping.

Posted
"rheostat"

A rheostat is a variable resistor that changes the voltage to the light bulb. As you change the voltage, the light will get brigher or dimmer. The rheostat will get warm-to-hot, depending upon the amount of voltage you're dropping.

This is of course true :o

BUT

I've NEVER come across a true rheostat dimmer in a domestic installation (they tended to be used to dim the huge movie lights and are probably no longer used in this application now). The dimmers you find in your house are electronic devices that 'chop-up' the supply effectively reducing the voltage withour dissipating any (much) power. So YES, using a dimmer DOES reduce the power consumption of the lamp :D

EDIT Look here http://home.howstuffworks.com/dimmer-switch.htm

Posted
Since the level of electrical expertise is so high on this forum, I'll tender a feeble question from an un-educated person (me):

Do rheostat dimmer switches actually reduce the amount of electricity used? I thought I read somewhere that all the rheostat did was keep the current from reaching the bulb, but actually consumed the extra current by converting it partially to heat? Now that I try to write that, it sounds totally implausible, but yet I'm sure I read something close to that. What's the real story?

Using a rheostat dimmer does reduce the amount of electricity used.....it just means that you aren't saving as much as you might think that you are saving. Instead of giving you the formulas which might be confusing I'll give an example. Suppose you have a light running full on and it is consuming 20 watts....then you turn the dimmer on so that now the dimmer and the light together are consuming only 10 watts....you might think that the bulb would be half as bright but you would be wrong....while you are consuming half as much power you are not using all of that reduced power to create light, you are dissipating some of that reduced power as heat in the rheostat so the light bulb will be less than half as bright...maybe one fourth as bright. The end result is that you do save power, just not as much as you might think at first.

But....I am only a rice farmer so as you know I'm luckless and clueless so you might want to get another opinion on this.

Chownah

Posted
Don't know about costs but aren't LED's very efficient, last almost forever....and dimmable?

Of course you would have to retool the wiring 'cause they're not 220V.

Yup, nowadays you can get them 12/24/110/220V in different packaging (replacement for halogen spotlight bulbs, normal light bulbs etc). Few suppliers in TH and crazy prices, but there are cheap and good ones available in China. A couple of more importers and they'll be cheaper here too.

imho LED light output will decrease faster than anticipated with BKK operating temperatures, particulalarly for ceiling fixtures, unless you go for heavy airconditioning (which doesn't really make sense if you use LEDs to save energy). I have a friend in China who is involved in LED manufacturing and export - he always tries to deny this, but I'm not convinced. Maybe they'll improve though.

Just my 2 cents, as a fish farmer.

Posted

a bit of insight (hope it is not too technical..).

Normal fluoresent lights work with those big transformers, used to create a high voltage to ignite them. The lamp itself will work on the net frequency (50Hz) and therefore flikkers at that rate. Usually this is too fast for anyone to notice, but it has (debateable) effect on the unconsious mind.

Those lamps are difficult, if not, possible to dim.

Those newer spiral shaped ones have some electronics in them which changes the 50Hz frequency first to DC and than create a high frequency pulse (usually around or above 20khz, so the human ear cannot hear it). It is possible to dim these lamps quiet a bit, since you can change (electronically that is) the so called "duty cycle". This will not change amplitude of the voltage, but the time it is on during that "pulse". This will make sure that each time enough energy is created to light the lamp.

I bet there are some "do-it-yourself" electronic schematics around on the internet, which show you how to build this....

good luck

Posted
imho LED light output will decrease faster than anticipated with BKK operating temperatures, particulalarly for ceiling fixtures, unless you go for heavy airconditioning (which doesn't really make sense if you use LEDs to save energy). I have a friend in China who is involved in LED manufacturing and export - he always tries to deny this, but I'm not convinced. Maybe they'll improve though.

Tempted to agree with you, this page http://www.ledtronics.com/pages/white-led-...e-life-test.asp has some life graphs for white LEDs at various temperatures.

Although they relate only to the LED device itself (and not the drive electronics required to run them from mains voltage), it's apparent that the effective life is reduced significantly between an ambient temperature of 25C and an elevated ambient of 60C. Cool them to -30C (Brrrrrrr) and they last forever.

Note, the LEDs don't hard fail as such (go out), their brightness reduces as they age.

Posted
Those newer spiral shaped ones have some electronics in them which changes the 50Hz frequency first to DC and than create a high frequency pulse (usually around or above 20khz, so the human ear cannot hear it). It is possible to dim these lamps quiet a bit, since you can change (electronically that is) the so called "duty cycle". This will not change amplitude of the voltage, but the time it is on during that "pulse". This will make sure that each time enough energy is created to light the lamp.

I bet there are some "do-it-yourself" electronic schematics around on the internet, which show you how to build this....

Trouble is, to modify the duty cycle of the tube you'll need to do some surgery on the lamp ballast electronics. Simply reducing the effective input voltage (such as with a conventional dimmer) merely results in the CFL drive electronics compensating and increasing the duty cycle automatically to maintain the light output.

I did some work years ago for Thorn Lighting (in Yorkshire somewhere IIRC), they had remotely dimmable fluorescent ballasts that used a 3rd wire to control whole floors of fittings, they also had staggered start so there was not a massive switch-on surge when the factory lights came on. Not really a domestic solution though.

Posted

since we talk here about lifetime... I've opened a couple of those fl saving lamps which broke down rather fast (1.5 year apprx.). If you use the expensive 6 years garanteed lamps, they do ok (4 years now, none broke), but the ones without 6years garantee, usually brake down due to heat and never on the tube itself (4 pieces checked), so if one would open up a new (cheap) lamp and extend the wires a bit to the tube, so that the small electronic board is further away (the lamp is light enough just to let it hanging on its wires), it would probably last as long(er) as 6 years...

Posted
since we talk here about lifetime... I've opened a couple of those fl saving lamps which broke down rather fast (1.5 year apprx.). If you use the expensive 6 years garanteed lamps, they do ok (4 years now, none broke), but the ones without 6years garantee, usually brake down due to heat and never on the tube itself (4 pieces checked), so if one would open up a new (cheap) lamp and extend the wires a bit to the tube, so that the small electronic board is further away (the lamp is light enough just to let it hanging on its wires), it would probably last as long(er) as 6 years...

You can probably fix the dead ones if you can identify (and obtain) the failed devices :o

I read on another forum that it's often the reservoir capacitor that fails, 105C device being run close to it's temperature limit, replace with a (more expensive) 200C device and we have a better lifetime :D

I suppose it depends upon how much free time you have, I'd love to be able to fix all the things that I've simply replaced over the years but it's just not practical, maybe once I retire I'll start doing stuff like that to keep my brain active.

EDIT this may be interesting http://www.irf.com/technical-info/refdesigns/cfl-2.pdf

EDIT 2 If you have the time it MAY be possible to modify a regular CFL to be a dimmable one http://www.irf.com/technical-info/refdesigns/cfl-3.pdf That would be a good excercise to save money :D

Posted

I've noticed a couple of different reasons for failure. 2x one of the wires to the tube lost connection on the small board. another board had a burnt copper track (though the diode was not damaged).

As I have always wanted to figure out how stuff works, I automatically learn how to fix them. And most important, how to improve them,... without burning or polluting the planet in my path...

If one has no time to do this, one is probably to deep entangled in the destructive path which many of us are following. too sad.

Anyway, most important: if you dim these cfl lamps, the energy used is less!! it is not wasted in some transformer but you actually reduce your energy bill!

Posted

I always buy the Chinese ones that cost around 60 cents a bulb. They don't last anything like as long, but I reckon it's cheaper, though not necessarily greener, to just replace than to pay $3-$4 for the more expensive variety.

The guy at the shop claims that they use more electricity than they say they do. Is that likely?

  • 4 weeks later...
Posted

We're adding on to our office and looking into lighting. The room is 6.5mX8m and needs to be quite bright. Our landlord wants to put in fluorescent bar lights but I want to explore options for low energy lighting. In my research (as often happens) I came across a relevant thread in Thai visa. I don't like the "color" of light produced by standard fluorescent lighting and would like something that still produces a very bright light but feels much warmer. I don't know much about lighting so any recommendations for what we could install would be appreciated. Thanks.

Posted

fluorescent lights are about as efficient as you can get for lighting large areas brightly....they come in different colors....have you looked at the "warmer" colors?

Also, which ballasts you get for your fluorescents has alot to do with efficiency....be sure to get the electronic ballasts....they are the instant on ones....

Posted
fluorescent lights are about as efficient as you can get for lighting large areas brightly....they come in different colors....have you looked at the "warmer" colors?

Also, which ballasts you get for your fluorescents has alot to do with efficiency....be sure to get the electronic ballasts....they are the instant on ones....

Thanks for the reply chownah. I hadn't checked into different colors of fluorescent lights. I guess I had always seen them in that "hospital white" and didn't realize that there are others. Thanks for the tip on ballasts too. From your posts in the chiangrai forum I understand that that is where you are located. As I am there too do you have any recommendations on where to shop for lighting other than Big C? I believe I've driven by a lighting/fan store on the road behind the bus station running towards the superhighway is that the best place to go?

Posted

CSS,

Don't know the best place to buy this stuff. We buy our lighting stuff either at Big C or the big Home Mart on the road that the buses use to get to and from the bus station or quite often at one of several small hardware stores that we know have reasonable prices. We have simple lighting so its cheap and available everywhere...we don't worry too much about paying 5 baht extra for something if its more convenient since the stuff we buy is pretty cheap wherever you get it.

Chownah

Posted
CSS,

Don't know the best place to buy this stuff. We buy our lighting stuff either at Big C or the big Home Mart on the road that the buses use to get to and from the bus station or quite often at one of several small hardware stores that we know have reasonable prices. We have simple lighting so its cheap and available everywhere...we don't worry too much about paying 5 baht extra for something if its more convenient since the stuff we buy is pretty cheap wherever you get it.

Chownah

Sounds good, thanks. I think Home Mart was the one I was thinking of.

Posted

You want it bright and you want it warm....

Usually, the warm atmosphere comes from warm spot-lights, not from long tube lights.

some advice:

-the electronic ballast saves the most AND is better for humans (EM)

-if you buy something with electronic ballast, don't go for the cheap stuff, as it usually breaks within a year, especially in an office (5days/week). Several brands (like philips) have those garanteed 6 years lamps (both in cold and warm colors) that are lasting.

-mix the long tubes and spots as you probably cannot go for 100% bulbs only.

To give an example: I work in an office-room which is meant for one person. I have 6x 36cm tubes in my room, which is a typical waste of material and energy. (6x 18w = 108w). I could do with a movable lampstand, attached to my desk which would only need a cfl of 11W....

good luck

  • 3 months later...
Posted
Hi . I was always under the impression that low energy light bulbs do not work with dimmer switches but someone told me they do.

Before I change all my lights is any one using these?

Thanks.

I'm new to the TV forum, so god knows if you'll get this. Make a point of not breaking the money-saving globes, as they contain mercury - a deadly toxin. Your kids breathe the vapour and it's bad news down the track for them. Major cleanup required for the room involved -probably unvailable in dear old Thailand. Oh, in case U R a man-made global warming panicker, whatever you do don't read climatescience.org.nz - U might wise up.

Posted
I'm new to the TV forum, so god knows if you'll get this. Make a point of not breaking the money-saving globes, as they contain mercury - a deadly toxin. Your kids breathe the vapour and it's bad news down the track for them. Major cleanup required for the room involved -probably unvailable in dear old Thailand. Oh, in case U R a man-made global warming panicker, whatever you do don't read climatescience.org.nz - U might wise up.

Whilst you are absolutely correct about the mercury content of CFLs, and you most definately should avoid breaking them. I think you're over stating the hazards should an accident occur. The average CFL contains between 2 and 5mg of mercury.

If you break one use common sense:-

  1. Exclude the kids (broken glass is more of a hazard than the mercury)
  2. Sweep up the remains, wear a mask and avoid the dust, do not use your vacuum cleaner.
  3. Seal the bits in a bag and put it in the trash. You may want to mark the bag as broken glass (my missus never bothers :o )
  4. Ventilate the room well

You should really send all your dead CFL and regular fluorescent lamps for recycling to avoid the mercury getting into land-fill but this is just not going to happen here just yet.

Mercury is not retained in the body ( http://www.mercurysafety.co.uk/hlthinfo.htm ) so its effects are not cummulative unless there is severe and constant exposure, so with a bit of common the odd broken lamp over your life is not going to do you any harm whatever :D

As to global warming, well it definately exists. As to whether we are the cause, well, we can certainly do no harm if we reduce our emissions can we?

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