LED v Halogen

derrick

Is there an easy way to compare LED lumen to halogen wattage?

Adverts usually only tend to show lumens.

What I am looking to do is to change my 300/500-watt floodlights to LED floodlights and maybe put some ion my garage to replace old fluorescents, but need to now how to compare apples and pears as adverts also tend to contradict each other when they try to compare lumens to wattage.


ETA, outside floods will require a PIR.


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[Deleted User]

There's no fixed relationship between power and light output for a filament lamp. This one is 16lm/W, but this one is only 11.4 lm/W, which is lower than my tungsten bulbs, which are 13.2 lm/W.

Kiran

It depends who's website you are using, as an example http://www.beamled.com/50w-biard-led-floodlight-with-pir-motion-security-sensor.html this shows the equivalent rating.

WobblyDog

My very unscientific rule of thumb is that a 10W external LED floodlight will be as effective as a 100W halogen, and probably smaller and more reliable as well. That might be partly because external halogen lamps tend to be brighter than needed anyway. I've been impressed with the small number of external LED lights I've come across.


For internal fluorescent lighting, the benefit is much less clear cut. Maybe 10W LED = 15W fluorescent at present.

bluesnake

All led's are not equal. Some one 1w led may emit quite a bit less than another companies 1w.

Some companies focus the beam more, so narrower and brighter light cone, but with less of an angle spread.

Also say if 0.1w led emits 1 lumen, do not expect a 1w led to emit 10 lumens, even from the same company, the graph is curved.

almillar

Wattage is a measurement of electrical power. Lumens is a measure of light output. A halogen floodlight at 300-500w will be putting out thousands of lumens.
This link shows 300W (well, 230W tungsten ones claiming to match 300w halogens) bulbs putting out 4650 lumens each.
https://www.amazon.co.uk/d/Light-Bulbs/Lighting-Halogen-Floodlight-Security-Dimmable-Tabular-Tungsten/B0064PQCFC/ref=pd_lpo_201_bs_t_2?_encoding=UTF8&psc=1&refRID=TC4M6PN1VQH7GRP1KM9C
If you want to match that brightness, you need that same number of lumens from the LED. Good luck with that!
You also need to consider:
Beam angle
Colour rendering index
Colour temperature.
A decent LED should be putting out close to 100 lumens per watt - if it's nowhere near that it'll be old or junk.

JP08

Something like this then :
https://www.ledhut.co.uk/led-flood-security-lights/50-watt-slimline-led-flood-light-180-watt-replacement.html

5,100 Lumen in cool white, 4,400 in warm white.

Popped one up on the garage over two years ago, doing fine so far.

They've got some that go way up in brightness, up to 17,700 Lumen

Jonesya

You can get a 50W LED floodlight from Osram (so reasonably reliable brand) for £30 that will give out around 5000 lumens, so equivalent to a 250-300W halogen.

http://cpc.farnell.com/osram/4058075001107/floodlight-led-50w-3000k-black/dp/LA06035

https://www.ledvance.com/products/luminaires/professional-luminaires/floodlights/ledvance-floodlight-led/index.jsp

For the garage fluorescents, well T8 fluorescents are very efficient so LEDs offer very little improvement particularly given the high upfront cost of a like-for-like LED replacement. I'd stick with the fluorescent, perhaps spend £4 on a new tri-phosphor tube and starter.

derrick

Forget to mention, outside floods will require a PIR.

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almillar

£60?! Compared to a £15 halogen, or the free one that's already installed, you'll have to be using it a lot to get the cost back. Plus the effort of installing it. And that one says it replaces a 180W halogen.

ic

I replaced a single 500W halogn floodlamp for two 10W daylight LED floodlamps on a long narrow drive. Coverage is much better and haven't had to change bulbs for years. I did test out a warm LED floodlamp on the garden, and much prefer the daylight option.