GU10 LED Downlighter query

[coopersim]

Hi, I've changed 9 GU10 50watt bulbs for 78 Warm LED style GU10's but am finding them a bit dimmer than the 50 watt bulbs even though they were advertised as 50w equivalent. Specifically which style of bulb would give the same output?

Also, the light given off seems to be a different frequency, a not so natural style of light, is this normal?

Please, no more suggestions to "install appropriate lighting, and get rid of downlighters" because it's boring and I've heard it all before!!!!!!

 

[skenk]

Unfortunately the advertising was exaggerating and yes, the colour from LED's is different to halogens (more blueish usually). Not really a lot you can do except install some more. You could use CFL bulbs instead but they will not fit properly in many fittings. The light output from these is closer to halogen (get 'warm white' ones) CFL manufacturers also exaggerate their output claims so go for ones advertised at about '60w equivalent' for actual 50w equivalent.

 

[ericmark]

I have found in my photography some odd results using LED lighting where the camera seems to see it as brighter than I as a human see it. This is not unusual the reverse is the case with sodium lighting where it seems quite well lit but the camera says it's much darker.

To measure light one must realise Luminous flux and Radiant flux are different and also the measurement depends very much on the angle so to prove manufactures have wrongly labelled with equivalent output would be hard to prove.

Using a camera to view inferred can be interesting and leads to incorrect focus due to different wavelength and it took me quite a while to work out why my black and white photos were out of focus. Hadn't realised how much light came from the LED's on TV and other goods in the room.

I also find, maybe because I am dyslexic that some light is easier to read under than others although I see it as being the same and I have assumed it is similar to covering the page with coloured sheets. With this in mind I think to say "The lumen (symbol: lm) is the SI unit of luminous flux, a measure of the power of light perceived by the human eye." is rather tongue in cheek since we know different humans perceive light in different ways as shown with both dyslexia and colour blindness tests.

So some standard of light meter must be set and this is unlikely to truly measure what we see.

 

[ban-all-sheds]

Not really a lot you can do except install some more.

Yes there is.

He could get rid of the downlighters and install appropriate lighting.

He's already replaced 9 halogens with 78 LEDs - how big a clue do you need to work out that "more of the same" is not the answer?

 

[Cremeegg]

Glad to see BAS is reading the OP.

Practically the sort of GU10 LED's sold by the sheds with about 18 LED's in one fitting are useless.

Go for at worst a 3W single LED which is arguably about the same as a 15-20W halogen. 5W LED's (usually 3 individual LED's) are about the same as a 35W halogen. 7W LED's are nearer a 50W halogen.

I've done several kitchens & bathrooms with 3W LED's about 450mm apart - the clients loved them but not so keen myself. I've done some with 5W LED's and two now with 7W LED's.

Need to check whether you like white or warm white and make sure its a decent brand Philips Osram etc. that use Cree LED's. There are many enterprising Chinese in this country running LED distributors some with poor quality LED's.

In ten years time we will wonder why we ever bothered with these horrible slow start bulky compact flourescents.

 

[Hotwire]

Doesnt coopersim mean 78 LED per bulb for want of a better word. Just looking at converting to LED,s from halogen due to a loft condensation problem. So coopersim how bad was the light reduction.

 

[ban-all-sheds]

Just looking at converting to LED,s from halogen due to a loft condensation problem.

How will that help?

 

[skenk]

Please, no more suggestions to "install appropriate lighting, and get rid of downlighters" because it's boring and I've heard it all before!!!!!!

He could get rid of the downlighters and install appropriate lighting.

 

[Hotwire]

Simple the halogens x 6 are 20w each, LED,s will be around 2w to 3w per unit max for 6 = 18w = massive heat reduction.

 

[ban-all-sheds]

What's up?

Did you think that coopersim has the right to tell people what they may or may not say?

 

[ban-all-sheds]

Simple the halogens x 6 are 20w each, LED,s will be around 2w to 3w per unit max for 6 = 18w = massive heat reduction.

How will reducing the heat given off by the lights deal with a condensation problem?

 

[flameport]

Condensation in a loft is usually caused by holes in the ceilings below, which let warm moist air enter the cool loft space, where it condenses onto the roof structure.
The other main cause is water tanks without lids, or a lid that does not fit properly.

To eliminate this problem, the ceilings must be sealed and the loft properly ventilated. (and get proper covers for any water tanks).

Changing lamps (light bulbs) will do nothing to improve the condensation problem.

 

[Hotwire]

flameport, the halogens are in a bedroom so they protrude through the ceiling into the loft. The insulation has been removed around each light in approx an 12" circle to save us being torched in our beds as we sleep. So lots of very hot air going into the loft from the wretched halogens plus the lack of insulation around them. Until these so called lights were installed there was not a problem.

 

[ban-all-sheds]

How will changing the lamp type do anything about the holes in the ceiling?

 

[Hotwire]

It wont, but im working on the assumption less heat less condensation.