Saving electricity.

[SUNRAY]

You’ve obviously not bought any incandescents lately. They are quite pricy now.

Indeed they are... But only to stop people buying them

 

[SUNRAY]

I would suggest if you are replacing LED lamps on a regular basis, that you need to look at just why they are failing. I began the swap to LED around five years ago, around the entire house, the only ones I then excepted were the less used ones, where it just wasn't worth while - most of those I have now swapped for LED.

The only failure I have had and had fail twice, has been an outside lantern type fitting with an 8w LED, providing some illumination on my drive, on dusk to 11pm each night. Last time I fitted a new lamp, I decided the reduced life was due to heat build up - so I spaced the top and bottom covers of the fitting, so there was an air gap.

Heat, lack of enough ventilation is a killer of LED lamps. Fittings which worked just fine with incandescents, might not have enough cooling ventilation for LED's.

I agree that airflow is/may be a problem. We inherited a 5 arm Chandelier from my sister many moons ago as it got through bulbs at a silly rate. Tulip shaped glass shades and the manufacturers sticker still showed 25/40W golfball B22's, sure enough they seemed to pop quickly but replacing with 25W candle bulbs being longer (taller) meant some of the heat was being dissipated above the shade and thinner meant there is better airflow between the bulb and shade. The shade ran cooler, albeit not much by feel and cured the problem...

Moving on to LED candle bulbs; they got so hot I couldnt touch the shade. Now that part of it doesn't make any sense to me as I can comfortably hold a running 15W candle bulb in my hand (Not the 25W size) but the 5W Philips or Osram (which in no way offer the same light levels in the room as the 25W incandescents) get far too hot to touch in a very short while. This is in a batten holder standing on the bench without a HO skirt so just about as free flowing as possible.

I was lucky I managed to get the last 3 packs of four candle 25W bulbs from a shed, 5 of which have been it use for several years and the rest will last a good few years yet, hopefully by then LED products will improve or Mrs Sunray will wish to change the fitting.

Pendant fitting elsewhere with a decent sized shade and 4" vent in the top we had a 60W bulb in there for maybe 15 years, in the early days the room was used as office/radio studio/toy room/spare bedroom (sofa bed) and it got lots of use, regular 2-4 hours per night. while doing my office work & Mrs Sunray/Master Sunray did regular shows for local and hospital radio & making jingles etc. Replaced it with Philips 11W Core-Pro (stated as being equivalent to 75W but far too dim), couple of days later replaced it with V-tac 15W (Stated as 85W equivalent) then when that failed Energiser 12.5W (100W equiv) followed by another. I estimate in the last 5-6 years I've had 3 failures compared to one in the 15 previous years. To me that is not the sort of longevity advertised. I haven't looked at running cost but I'll hazzard a guess I'm out of pocket

As it happens the use of the room has fallen, my self employed work dropped right off about the same time as the bulb failure which means my time on the 'office' computer has been minimal and daughter moving house about 4 years ago coincided with son going self employed and giving up his radio work, we swapped the sofa bed (or should I be getting down with the kids and call it a futon?) for her youngests captains bed and the studio was dismantled to make the space for it.
I'll plump for poor design or build quality that so much heat is generated (and wasted) in the control of such products and not enough dissipation is designed in.


It's all very well being told LED products are a direct replacement for a previous device but my experience of performance and longevity indicates differently.

Am I anti LED for lighting?
I was for a long time as in the early dasys it was quite frankly crap until progress got it to a better stage. Mostly LED lights are good as long as the flicker isn't a problem, especially with epilepsy etc. (most digital cameras/phones/CCTV now have oodles of software to overcome the problem but has caused problem with evidence gathering and courts). Some still has a way to go, I can't begin to count the number of Fluo tubes I've changed to LED then been back to double or tripple the quantity or reinstate to Fluo (when converting existing fittings to LED I do as little as possible damage to make reinstatement easy) and the ceiling grid panels seem to be even worse as they are so directional, almost as aweful as spotlight/downlighters.

Colour rendering can cause problems, the pigments used in wire colouring show up differently under different lights and some colours are confused. In one cable White looked pink, blue looked black & black looked grey. Orange and yellow often look the same, as do red and brown. When wiring multicores under LED I ensure I have another lightsource.

I still do 'public entertainment' sort of stuff and have a fair bit of LED products, things like 10-50W floodlights, red,green,blue stage lights etc, most of which is very effective and simply makes the job much easier. LED tape to light van interiors properly has to be experienced to be believed.

 

[RandomGrinch]

Moving on to LED candle bulbs; they got so hot I couldnt touch the shade. Now that part of it doesn't make any sense to me as I can comfortably hold a running 15W candle bulb in my hand (Not the 25W size) but the 5W Philips or Osram (which in no way offer the same light levels in the room as the 25W incandescents) get far too hot to touch in a very short while.

Some interesting comparisons between incandescent and LED bulbs from LEDs Magazine here:

Fact or Fiction – LEDs don’t produce heat

An often-quoted advantage of LEDs is that they don’t produce heat, and are cool to the touch. Fact or fiction?

www.ledsmagazine.com

I may be wrong, but I would also guess that the heat output from an incandescent bulb would be fairly evenly distributed at a low level, around the glass, but will have a hotspot around the metal cap (that can't be touched when the bulb is on!), and further dissipated into the light fitting.

The LED bulbs are mostly made of plastic, have driver electronics concentrated in small compartments with no ventilation and most of the bulb is touchable when turned on.

Could it be that incandescent bulbs are just far more efficient at dissipating heat, than LED bulbs; and as from the link, a higher proportion of the LED's 'wasted' energy is produced as heat rather than IR?

 

[Harry Bloomfield]

Could it be that incandescent bulbs are just far more efficient at dissipating heat, than LED bulbs; and as from the link, a higher proportion of the LED's 'wasted' energy is produced as heat rather than IR?

No. LED's turn around ten times as much of the energy into light, the issue is that the tiny proportion of heat generated, is more difficult to get rid of and the electronics are very sensitive to heat - that is not the case in incandescents, they have no electronics. The outcome is that a fitting designed and able to run at a very high temperature with an incandescent, even though LED's do run much cooler, the design of the fitting may not allow LED's to run cool enough.

Hence people installing LED's in unsuitable fittings and the LED's not giving the expected working life.

 

[RandomGrinch]

No. LED's turn around ten times as much of the energy into light, the issue is that the tiny proportion of heat generated, is more difficult to get rid of and the electronics are very sensitive to heat - that is not the case in incandescents, they have no electronics. The outcome is that a fitting designed and able to run at a very high temperature with an incandescent, even though LED's do run much cooler, the design of the fitting may not allow LED's to run cool enough.

Hence people installing LED's in unsuitable fittings and the LED's not giving the expected working life.

Yes agreed, and that is what I was trying to get at (maybe unsuccinctly) in the rest of my post
I was mainly trying to theorise why Sunray felt the LED bulbs were warmer to touch than the incandescents.

 

[Harry Bloomfield]

Yes agreed, and that is what I was trying to get at (maybe unsuccinctly) in the rest of my post
I was mainly trying to theorise why Sunray felt the LED bulbs were warmer to touch than the incandescents.

I cannot take hold of an incandescent which has been on for a while, apart from maybe a pygmy lamp. I can easily unplug an in use LED without need for a cloth, generally they are no more than warm.

 

[JohnW2]

I cannot take hold of an incandescent which has been on for a while

... same here. In fact, I'm not so sure about "a while". I would say that an incandescent bulb of any appreciable wattage becomes too hot to touch very quickly (probably not an awful lot of seconds, probably a fair bit less than a minute).

I can easily unplug an in use LED without need for a cloth, generally they are no more than warm.

again, ditto here.

Kind Regards, John