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Lumen output for undercab xenon vs LED??

Posted by catbird (My Page) on
Fri, Mar 9, 07 at 11:07

This was posted on the kitchen forum. I'm also interested in the answers, so am taking the liberty of copying it to this forum:

Posted by paul_ma (My Page) on Fri, Mar 9, 07 at 0:00

I have been trying to decide between xenon and LED undercab lights. One clear difference is that the LEDs aren't dimmable. That left me wondering whether the LEDs will produce a suitable amount of light.
So I have tried to compare the output of alternatives. I considered Kichler Xenon fixtures, Seagul strips, and LEDtronics LEDs. My first problem was getting comparable numbers. LEDtronics quotes lumens, but the others only give watts per bulb. After some hunting, I found a value of 250 lumens for an 18w xenon bulb, and claim that was roughly equivalent to a 25w incandescent bulb.

The Kichler fixtures have about 1 18w bulb / 6", or 500 lumens per linear foot.

The Seaguls linear seems to support anywhere from 2 bulbs every 4" to 1 bulb every 6", and bulbs from 3w to 18w. So that leads to brightness of anywhere from 65 to 1500 lumens per foot.

The LEDtronics "warm" lights are about 40-50 lumens per foot.

That relieves my concern about the lack of dimmability in the LEDs. Instead, it seems like they are MUCH dimmer than all but the most sparse Seagul installation. The Kichler fixtures, even when dimmed 50% would be more that twice as bright as the LEDs.

The above is all just cranking numbers. I don't know anything about lighting, about what a reasonable installation of the Seagul might be, or how many lumens is appropriate for undercab lighting. But it certainly sounds like the LEDs might be more suitable as ambience lighting than as task lighting.

Does anone have better data or insight into this?

Where have out lighting experts gone? (I suppose we burned them out with too many questions.)


Follow-Up Postings:

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RE: Lumen output for undercab xenon vs LED??

I'll try my hand at this. I'm planning to use xenon UC lights. Specifically, I'm planning to use the ones sold by Pegasus, which consist of exposed festoon bulbs mounted on a wire - no housing of any sort surrounds them. The Pegasus website doesn't offer great photometric data on them, but another company with a very similar product does. I'll use their numbers.

This competing product (Linea) claims 40 lumens per five watt bulb. If they are mounted 3" on center, or four per foot, that would give you 160 lumens per foot. If mounted just behind a light rail, the gradient of light on the counter supposedly ranges from 31 footcandles at the bottom of the backsplash to 27 footcandles under the front edge of the upper cabs, and then decreases more rapidly towards the front edge of the counters because the light rail itself gets in the way. 27-31 footcandles is not great task light by itself, but it is enough to nicely complement overhead lighting, or for use at night when you don't want the lights bright anyhow.

To the extent that those numbers are accurate, and to the extent that the light distribution patterns of LEDs are at all similar, 40-50 lumens per foot would, frankly, suck.

I did see some LED UC lights on display at a big box store the other day, and they were dismal. I didn't notice the brand.

On the other hand, 500 lumens per foot as claimed for the Kichler fixture would be quite bright. 1500 lumens per foot, as with the high-wattage Seagulls, would probably be far too bright for UC purposes, and is probably more appropriate for cove lighting, where a whole room is lit from the edges of the ceiling.


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RE: Lumen output for undercab xenon vs LED??

I'm not sure which LEDtronics strips were being looked at, but the two links I have to their site show 89 lumens for a 12" strip in the warm color temp and 116 in the cooler ones.

I still have them on my short list for UC usage. Along with Xenons from Sunrise Lighting - not as impressed with the Pegasus prices and mounting. I'd probably be going with 6 to 9 inch lamp spacing on the Xenons. I just don't want UC to be overly bright nor suck down too much power. The lighting is to be accent oriented rather than task-based.

Bruno


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RE: Lumen output for undercab xenon vs LED??

hybrid,

You are looking at the same page I am. But I botched and looked at the foot-candle numbers rather than the Lumen numbers. So its not as bad as I said.

The listed values are: 6" - 40, 12" - 89, 24" - 158. So that is between 79 and 89 lumens per foot.

Something close to the power of the the Kichlers could be had with the Seaguls using two 5w bulbs every 4". That would be a bit more than 400 lumens per foot.

But I don't have a real sense of whether this would be blindingly bright, task bright, or whatever. The advantage I see with having xenons that are more than bright enough is that they can be dimmed to whatever is wanted.

I'm going to have dark cherry cabinets and brushed black counters (with light colored backsplash). I think this will suck up the light, so I'd rather err on too much than too little.

I suppose it might be possible to double up the LED strips and switch them separately. That would give at least two levels of brightness. But at this time I think I am tending toward xenons. And with the strip lights its possible to add more bulbs, or take some out, to tune things.

Here is a link that might be useful: LEDtronics


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RE: Lumen output for undercab xenon vs LED??

Thanks for that link, Paul. It's good that they're at least publishing some hard numbers, but the "Total LED Foot Candles" column is problematic. Footcandles are not a trait of the lamp itself, it's a measurement of how much light falls on a surface, and is a function of the candlepower of the lamp and the distance of the lit surface from the lamp. "Total LED Foot Candles" doesn't make any sense.

I do think you're on the right track. 116 lumens per foot is not much in any situation, let alone matte black countertops. The light backsplash will help, though.


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RE: Lumen output for undercab xenon vs LED??

Have you considered flourescent undercabs? There are very slim fixtures available which put out plenty of light and very little heat. They come in various color temperatures from cool (old-fashioned flourescent) to warm (similar to incandescent) and "natural daylight." A couple of companies that have them are:
http://www.brodwax.com/undercabinet.html
http://www.pegasusassociates.com/products/Undercab/undercab.html

I'm trying to decide between flourescent and LED, and may go with flourescent because of the brighter light.


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RE: Lumen output for undercab xenon vs LED??

Just a note -- American Fluorescent is a leader in the fluorescent industry and has been coming out lately with a vast array of lighting. They have several task lighting series to use. Also, not only are fluorescent fixtures brighter, they are much cooler. We have had problems with the halogen and some xenon heating products in the cabinets. From personal experience, sometimes the replacement of the bulb is a problem with the xenon lamps. I have had a fluorescent under cabinet light on 24/7 for 20 years and have replaced the bulb twice. We have used it as a night light in the kitchen forever.

Also, please remember when doing your kitchen that if you have a shiny counter top, whatever you put under the cabinet is going to reflect on the counter. We encountered this when installing lights for a customer with a very high gloss counter top finish.


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RE: Lumen output for undercab xenon vs LED??

When considering the undercabinet lights reflecting off of the polished countertop, would fluorescents be a less offensive reflection because they are more of a flood light than either xenon or LED's?

Quick responses would be appreciated. I'm close to deciding for my kitchen!
Thanks.


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RE: Lumen output for undercab xenon vs LED??

If you have reflective granite, you'll have an issue with anything.

Xenons tend to have multiple bulbs within a fixture. So hotspots will be more noticeable.

Fluorescent and certain LEDs will not- as the light output is evenly distributed along the length of the fixture. And most LED undercabs have optics which specifically blend the LEDs so that you get an even wash of light from about 2" away and farther.


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RE: Lumen output for undercab xenon vs LED??

Our countertops are polished porcelain tile, which is quite shiny. Our undercab lights are T-5 fluorescents and we're happy with them. Reflection hasn't been a problem and the light is good.


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RE: Lumen output for undercab xenon vs LED??

Do all of you have light rails? I realize now I probably should have ordered a light rail. I don't think it's too late and will probably greatly expand my lighting options, eh?


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RE: Lumen output for undercab xenon vs LED??

Our cabinets came with a 1" overhang, which is enough for the low profile T-5s. Guess it will depend on how your cabinets are made and what kind of lights you're going to use.


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RE: Lumen output for undercab xenon vs LED??

I decided to go with a light rail, as the overhang is barely one inch.

This is quite the challenge. Don't want the heat or watt expense of halogens (have 9 cans in the ceiling already) but I really want something dimmable. Xenon seems questionable for the same heat reason; flourescents too bright and non-dimming; LEDs not bright enough. Then there's the whole line- vs. low-voltage issue.

I'm thinking I'll go with cheap-cheap small, low-watt flourescents for now, as it seems there's a great need for a perfect undercab lighting solution that'll no doubt be brought to market as soon as I complete my installation. :P As long as the hard-wiring in in place in the cabs, it should be no sweat to upgrade a few years down the road.


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RE: Lumen output for undercab xenon vs LED??

I was at a lighting store last night (the best I've visited), and looked at both xenon and LED. The representative says he has xenon at home, b/c the LED technology wasn't there when he bought his undercabinet lighting. One thing he has noticed is that over time the xenon light gets weaker, and there is a yellowing effect. So, he replaces the bulbs even though they aren't burnt out to get the crisper light. He also says they still do give off heat ... they're not the cool alternative some thing they are (though of course they are cooler than halogen). He did say they are a good product, all things considered.

But, he's now recommending the LED for undercabinet (but not in-ceiling) use. The light is beautiful. The installation is as low-profile as I've seen, and the energy savings are nothing to scoff at. They're not dimmable, yet, though he says the manufacturer (of the switches) is working hard on this, and expects to have something soon.

I'm now seriously leaning toward the LED for undercabinet lights, including for my floating shelves, which I didn't think I would be able to light until now.


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RE: Lumen output for undercab xenon vs LED??

I second Venice's experiences.
LEDs are more than bright enough now.
The under cabinet LEDs I'm using in my garage as a work table light is amazing. The main lights of the garage aren't working now. Just turning on the LEDs actually send light a good 15 feet away. It's not super bright at the other end of the garage. But it's definitely bright enough to see and not trip.
It's also dimmable. Although I just have a switch on it now.


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RE: Lumen output for undercab xenon vs LED??

We manufacture LED under cabinet lighting. Yes they are dimmable and they will produce more light than you will ever need. We build custom length fixtures in increments of one inch up to 12' long (cove lighting). We offer two different color temperatures: 3500K warm white and 6500K cool white. I will tell you that 90% of our sales are in the warm white. They take minutes to install. Our standard size fixtures are now being offered at some Home Depot stores in the midwest. Feel free to email me and I will send you some of our literature. Also, you won't be able to fry an egg on our fixtures like you could with the xenon fixtures.


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RE: Lumen output for undercab xenon vs LED??

For emeralight:

I looked on homedepot.com and couldn't find the lights to which you refer.

We are putting in undercabinet lights in our kitchen but cannot find good quality affordable led lights. If you cannot post product information here could you email it to me at

leonardz@sympatico.ca

Thanks.


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