LED troffer lights

more light?

Bill Tindall, E.Tn.

When I have compared LED shop light to T8's the T8 provided substantially more light per fixture or lamp. For most of us the cost of electricity to light our shop is insignificant. Hence, what we should be buying are the most lumens of our spectral preference for the buck.

Looking at the lamp surface is an unreliable way to determine light output to the bench. Looking at the metrics on the lamp is the reliable way to determine which provides more light. Better yet, a light meter on the bench measures what is important.

What is the "lumen" output of the LED lamp or fixture? Typical T8's are in the range of 2900-3100 lumens per lamp, so a 4x4' toffer yields about 1200 lumens.

For my money the high output T5 lamps are the way to get an adequate 200 foot candles on the bench surface. I am skeptical enough LED fixtures can be hung above the bench to reach this level of lighting. (Outside in the shade is about 500 foot candles for comparison. )

Re: more light?

Don Evans

I recently hung a 7500 lumen 4 foot LED light above my carving bench, it is almost more light that I need. I purchased it from Rockler and they have another 4 footer that is 10,000 lumen. Talk about a lot of light.

Don

Re: more light?

JL

The 2 x 2 Metalux troffer claims to have 4200 lumens at a color temp of 4000K.

The 2 x 4 Metalux troffer claims to have 4700 lumens at a color temp of 4000K.

The price is $55 for the 2 x 2 and $ 65 for the 2 x 4.

I replaced a 2 x 2 in the library portion of the basement and a 2 x 4 in the shop side of the basement. The 2 x 2 replaced a 2 bulb (bent bulb) fixture. The 2 x 4 replaced a three bulb fixture. Both have more light than the fixtures that they replaced. The reason behind the replacement was a test to see if a LED fixture would generate less RFI for the FM radio stations that we listen to.

The experiment was a success. There is little or no RFI with LED fixtures as opposed to the fluorescent fixtures. The extra amount of lumens was an added benefit.

correction to my metrics

Bill Tindall, E.Tn.

advice to self: don't send a post in a hurry

"What is the "lumen" output of the LED lamp or fixture? Typical T8's are in the range of 2900-3100 lumens per lamp, so a 4x4' toffer yields about 1200 lumens"

The correct data are:

A 2 x 4 T-8 Troffer fixture (4-lamps) will produce about 12,000 lumens. It took 3 of these over my bench to get 200 foot candles of illumination at the bench surface. All this overhead acreage was replaced with 2- 4 lamp T5HO units that produce 20,000 lumens each.

RF interference

Bill Tindall, E.Tn.

This interference to FM signals, radio or TV, comes from the ballast and varies with ballast. I replaced the ballast in a fixture in the kitchen and the new one wiped out one channel of the TV. Before I got around to selecting a ballast that didn't interfere we went to satellite TV which avoided the problem. If you face an FM signal interference, an option is to replace the ballast and not the fixture. You may have to go to a "full service" lighting store to get a suitable ballast.

Re: more light?

Larry Clinton At Frankfort, (Central) Indiana

I replaced all of my high usage incandescent light bulbs with LED's. I also had a 2' fluorescent over the kitchen sink that is on 24/7. I replaced it with an Led not for more light but for the added life, but it is much brighter with (to me) a better color temperature.

I agree in most cases, there is little lumen output gain, but the issue of replacement cycle is also important to me. I doubt the energy savings or even the longer life is economically advantages, but the convenience and color temperature is worth the cost to me!

I will say the newer (albeit more expensive) LED's do seem to put out more directed usable light then those of a few years ago.

Color temperature and quality

Bill Tindall, E.Tn.

An incandescent is what it is for better or worse. Ditto for halogen which is bluer/whiter. No lamp offers a wider array of color temperature and light "quality" than T8. Color temperatures from 3000 to 6000 and CRI up to 90 are available in stock at a large light store or by order.

The ability of LED's to generate light of varying color temperature and quality (CRI) is more limited. The most common way to get "white" is to simply mix the native blue from the LED with yellow which produces a white of moderate CRI.

Given the rapid advances in LED technology current LED lamps will be obsolete in some factors, for example CRI, long before they reach the end of their anticipate life.

How about free....

Barry Irby

At one of the auctions I go to there are often pallets of various troffer lights. Recently I was helping my friend load what he had bought and saw someone throwing slightly damaged one in the dumpster. I asked if I could have them and they gave me two. Slightly dented. I hooked a cord to them and they work. 2 X 2 LED lights. Now I just need to work up the energy to install them. And keep my eyes peeled for more. Free is good, don't you think?

And I agree with Bill. LED's appear to be emerging technology. Might be better to wait a while. For now, I am sticking with my T-8's. Unless free comes along again.

Re: LED troffer lights

Walt

I've replaced fluorescent tubes from the borgs with LEDs. Doing so fixed ballast problems - I ripped the ballast and most of the wire out of the fixture. The LEDs I bought are powered from one end, the other tombstones are just to hold the tubes. Instant on, no color change with tube warm-up. My fluorescents had pretty short lifespans, I think in part due to frequent power cycling. I know fluorescents don't use much power and we should just leave them on even when we're not in the room but old habits die hard. Power cycling is not supposed to affect LEDs or so they say.

Re: LED troffer lights

Don Goodwin

I've done the same thing (removing the ballast and replacing the tombstones) as my florescent lamps act up. I've wondered if I'm being cost effective - the LED bulbs cost $15 each at the local ACE hardware? I've not priced new LED fixtures, but it would bother me to throw out the old fixtures. So far I'm happy with the light. I now have 3 converted LED fixtures and 2 remaining T-8's.