LED lighting

my eyes are very sensitive to light and I have trouble with the fault finding flicker in cars but no problems at home......I find a nice white blue light is much better tan that yellow flourescent rubbish we have had to suffer to save energy in the past and my meigrane with aura is no worse with LEDs ....however my kooncil is getting flack for bad led street lighting...

LED is unlikely to give continuous spectrum light as you'd get from tungsten. It might be better or worse than CFL, though, which has the same problem. All depends on how well they are made. Budget ones may be worse than those from a high end maker.

I've never noticed any flicker from domestic LEDs. If high frequency flicker you can't see can give you migraine, I dunno.

LEDs often appear brighter to look at. Sometimes uncomfortably so. But seem to produce less light to the room than this suggests.

Here's a question for the group.

Average family living in an average 3 bedroom family house using the average amount of electricity.

They change from all tungsten lighting to all LED.

How much money would they save on average per year on their leccy bill?

Too many variables to be accurate but as a rough guide I would say if you have current 60w and move to say 12w LEDs then the lighting part of leccy bill would approx a fifth of the cost (not including the cost of the LED bulbs)

Around 80-90% of their lighting costs. So, say, 4x 60w lamps on , thats a quarter of a unit a hour, so what, around 4pence per hour. Add on a few more for larger houses and multiple fittings in kitchens/ bathrooms, then you'll be up to 20 pence per hour.Average for 4 hours throughout the year is reasonable, so 4 x 20p x 7 £5.60 a week (seems a little high?) = £292/ a year. With LEDS it'd be 2-3p per hour, 84p per week, £43 a year.

Of course, usage will change in every house, I'm at the lower end, other houses I've been to rival Blackpool for internal illumination.

Perhaps slightly offset by the temptation to leave them on for longer, on the basis they don't really cost anything?

No.

Lighting industry did lots of experiments with CFLs to try and understand what people didn't like about them. However, it was quickly shown that these people didn't like lights they thought were CFLs and did like light they thought were filaments. Since what they *thought* didn't match reality, it could only be put down to physicological bias, not genuine physiological issues.

Of course, there are poor quality CFLs and poor quality LEDs, and if you buy those and don't like them, then don't be surprised.

Some dimmable LEDs have no smoothing of the rectified mains, so if you don't like 100Hz flicker of moving things, avoid dimmable LEDs.

Complete mess up of figures. That is a little high, as it should be 4p/hr x 4hrs =16p/day = £1.12/week =£58/year With LEDS it'd be between £5 and £10/year.

Couple of findings from peer reviewed sources:

"LED appears to support positive mood, extended wakefulness, and speeded performance on both visual perceptual and cognitive tasks" in a work context.

More general associations between LED light and well-being would need somebody quite specialist, I'd think. Found this very odd sentence:

"Although highlighted in the scientific literature, concerns about the potential impacts of increases in LED lights on cancer or other chronic health outcomes were not raised by residents or key informants in any settings in the fieldwork, public or private" (Reduced street lighting at night and health, Health and Place 2015).

Overall, though, I think the evidence of a link between well-being and LED lighting is weak. Trafford did a study using plain English which was largely inconclusive: Trafford LED Street Lighting Programme Health Impact Assessment (2013) - I've only skim read it though.

As for those physical/physiological relationships listed by the OP, don't know - that literature is far too specialist for me.

I'd say anecdotally that I find the street lighting superficially bright

- it seems at first glance as though more is illuminated, but I can't distinguish as much. Potholes for example - a big problem cycling at night.

At home (just about all LED now), I don't notice much difference between tungsten and LED, once the problems of LED directionality and overly bright source are removed. Decent bulbs and/or shades largely solve these issues for me.

Never got on with CFL - glad to see(!) the back of them.

It`s a peaky spectrum and the effects are subject of investigation and controversy

Flicker should be well above perception level, as demonstrated by numerous crap car tailight designs this basic appears to have escaped some makers.

Simply not as bright, just not as much light coming out the front.

Because lighting is something that `just happens` and dosen`t need specialists with years of training and experience in their field.

It`s not all wrong but a bit misunderstood in places.

You and me both. I've started chucking them away even though they still work (for quite small values of the word "work".) Although I have a huge box of them, I don't think I ever paid more than a few pence each for them, and that was a waste of money.

in on my own account, always remember to sign out of gmail on a guest machi ne....

C`mon Andrew, that is at best insincere, their are known physical issues wi th CFLs to photo sensitive people

"some energy saving compact fluorescent lights may emit ultraviolet radiation at levels that, under certain conditions of use, can result in exposures higher than guidel ine levels. The HPA?s view is that single envelope CFLs should not be u sed where people are in close proximity - closer than 30 cm or 1 ft - to the bare lig ht bulb for over one hour a day. "

In the interests of balance ;-) heres industry response to AMA LED warning

CFLs have a peaky spectrum, (some?/most?/all?) LEDs are broad like incandescent

Buy yourself a diffraction grating if you want to check any particular LED ...

You cannae change the laws of physics, blackbody radiator like tungsten has a continuous spectrum, sources that rely on phosphor conversion will always have peaks and troughs.

LEDs , of any current type, are many miles away from being broad band sources.

Work with LEDs come home to halogen in the main

Will let Mr Craig Johnson at the LED Museum show in more detail

I said "broad" not "continuous"

You did look at the spectra on the page I linked to? It looks one hell of a lot better than CFL to me.

Snag with that is it's near impossible to know what proportion of your leccy bill goes on lighting.

All that really is saying is that 'bluish light isn't great because your body thinks its daytime'.

But LEDS do not come solely in bluish white. The spectrum can be balanced - more so than mercury vapour lights.

Some car LEDs are driven in a very different way from domestic mains LEDs. Basically, you can't just transfer a problem with those to all.

been looking at source spectra for 30 odd years, mebbe I read them differntly from yourself ;-)