a) do we need lighting to be so much brighter?

b) I cannot see where they have allowed for the increased heating energy needed to replace the loss of "wasted" heat energy from the old lighting --- THIS IS VERY SIGNIFICANT.

c) I agree that LEDs will take over.

Tony: a lot of those lights are *exterior*. Are you really going to claim that their heat output is useful at *any* time of year?

Rgds

Damon

a) do we need lighting in stair wells and corridors on 24/7? or even all the time when it is dark? -- Exterior lights should all be LED's but NOT on during daylight see their photos!!!!

b)It is most unscientific and misleading to claim that all the energy saved is being saved when some has to be replaced by additional heating -- money and efficiency issues aside

d) agreed not just social housing but anywhere people are paid to change luminaries,

The higher the cost figure for electricity used the better the savings look

I finally got around to reading the report and found it very disappointing. It seemed to have been written by a marketroid or a spin doctor rather than an engineer or scientist.

It was very difficult to find hard raw facts in the report, it all seemed to be 'normalised' in different ways in each table and there was very little information about what was installed originally, making it difficult to judge any comparison about savings etc.

Much was made of different colour temperatures, attributing this as a benefit of LED technology. But both LEDs and fluorescents are available in pretty much any colour temperature you ask for. So as far as I can tell, its simply a different opinion by whoever chose the old and new lighting. As someone who prefers 'daylight' lamps himself, I'm well aware that most people choose 'warm white' - that's why it is most commonly available. It's got nothing to do with LEDs.

The published photography was hopelessly biassed. (The report writer's bias rather than the photographer's). If I understood the methodology correctly, they deliberately used under-exposed pictures of the original lighting where it was dimmer, which of course makes it look terrible. They should have also published at least the correctly exposed original lighting and the corresponding over-exposed new lighting if they wished to be objective. I think they also deliberately used the wrong colour balance, which again is an unfair trick.

With regard to the hours of lighting, it looked to me like a lot of this lighting was public safety and security lighting, so it's not too surprising that it was left on 24 hours a day. People having confidence in their own safety is more important than the last bit of energy saving. It is true that modern automatic daylight control systems can help achieve both goals in the right circumstances and these are increasingly being fitted.

Posted By: DamonHDThere was a long long note by the photographer at the beginning saying how they avoided adjusting any colour balance and made sure that they took exactly paired shots by exposure, etc, before and after.

Exactly. That's how I know it was the writer's fault not the photographer's. Read it again and think about what they wrote in the context of what I said.