Hello LED Experts,
We need ur advice. We have an art gallery in which we use around 200, 50w, GU5.3 base, osram decostar halogen lamps, plugin type as spot light on paintings.
http://www.osram.com/osram_com/Consumer/Home_Lighting/Halogen_lamps/Product_overview/Plug-in_bases/HALOGEN_ECO_LAMPS/DECOSTAR_51_ECO/index.html
We want to replace these with suitable LED based lights. We explored the market and best LED that we have been able to find are chip / SMD , toyoda gosei LED based product which offers 80 l/w in warm white color. These are 3w, 12v, lamp with beam angle of 60 deg. These get fit into existing halogen light fitting.
Is this suitable replacement? Is 80l/m good enough? what other option do we have?
Vikas
Vikas,
The LED parts you are asking about are only about 240 lumens. The 50 Watt halogen bulbs you are using have a lpw efficacy of about 24 lumen per watt - so they are effectively around 1200 lumens.
The LED parts you are looking at are not going to be enough light. The ones you are looking at are usually used to replace 20 Watt halogen.
Additionally - please note that the color rendering index or CRI of the LED bulbs are only going to be about 70 and the halogen bulbs you are using are 95 or higher. What this means is that the artwork you are lighting will look rather poor.
We make an MR16 12VAC version of the halogen bulb but we only go after residential applications - mostly landscape lighting. Here is our CALCULATOR
I do not think LEDs are ready for your artwork lighting application yet. Best thing you could do is to take your 50Watt parts and add a dimmer to reduce power about 10% - let the parts run cooler, you will greatly extend lifetime.
Hi Manual, thanks for your valuable inputs.
From what we have measured, halogen lamps have very high lux level just in front at a spot at 1m distance. As we travel away from the light in a one metre circle its lux level decrease sharply. At around 1 meter the lumen level difference is comparable.
We display paintings of size in the order of 1X1m or more in art gallary.
The LED lamp that we are considering has CRI of 78. So is a difference in CRI from 95 to 78 considerable?
There is a correction, the LED lamp has efficacy of 55 lumens per watt in warm white color and not 80. So LED lamp has total 165 lumens compared to 1200 of halogen, which i agree is pretty low.
What did you end up using in your gallery? I'm working with a gallery in Pennsylvania trying to come with a solution.
The best solution by far is the Osram "ECO" Halogen which saves 30% in energy. The 35W "ECO" MR16 puts out more light than the standard Decostar MR16, has a 5,000-Hour life, and a constant color reflector so the light output remains consistent over the life of the lamp. It has a UV shielded front lens as well.
LED is just not ready for this application yet. We have MR16's in LED now up to 390 lumens with a new Nichia chip, but Color Rendering is only 80, while all halogen including the Osram ECO has a perfect CRI of 100 which is extremely important when selling artwork or any other high-end retail item.
Check the lamps out; www.fusacorp.com/ProductDesc.aspx
Best Regards,
Craig A. Klomparens
FUSA CORP
i am using 3w LED from a company called Fawoo from South Korea. I had replaced 50w halogen lamps in tracks with these lights in the same fixture and these are working fine.
We use the Philips 7w LED MR16 to replace these in several different installations. These work great for retail applications and replace the 50w Halogen lamps. If you have 20w Halogen lamps then i suggest you give these a try they might just do the trick. Their CRI is 83 and produces 370 lumens, the lpw would calculate to be be about 52 lumens per watt. These LEDs are also dimmable. If you would like more information or a sample let me know.