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JoeLee
06-17-2014, 02:46 PM
It's getting time to replace some of the T-12 4 footers in my shop fixtures which are the 2 x 4 drop in type.
The bulbs that are in there now are ValuLite 40 watt and probably cool white. I think there is better stuff out there now as these tubes are at least 15 years old.
Looking at the Phillips brand at the local HD I have a choice of:

Day Light Delux 40 watts 2325 lumens 6500K CRI 90


Natural White 40 watts 2500 lumens 5000K CRI 90


Cool White 40 watts 2600 lumens 4100K CRI 89

I don't think I'll go with the cool white but I listed it for comparison purposes to the other two lights.

If I remember correctly the higher color temp will start to throw a bluish cast. So I'm wondering if any of you guys can make a recommendation since were all looking for the best lighting we can get for our shops.
I hate to buy a case of each just to see which one will light the shop the best.

JL.....................

Paul Alciatore
06-17-2014, 05:44 PM
Just precisely why are you concerned about the color temp?

Personally, I would go with the cool white because that would show the most correct colors of anything I am examining. But if you have some concern, then that needs to be known before any recommendation could be made for your situation.

On top of that, your eyes will adapt to the color temperature of the bulbs that are in use. So, to a great extent, after you are in the room for a few minutes, you will see much the same thing. Yes, there will be some small differences. Some colors may stand out more or less, but overall things will look normal. Different preferences for different color temperature bulbs are mostly a matter of personal preference. That sounds like circular logic, but it is true.

RussZHC
06-17-2014, 05:51 PM
Falls under the category of "what the boss wants the boss gets"...not in a shop but at work our locker rooms are lit by lamps you describe, comments are pretty often that anything more than 4100K is "too blue".
Truthfully I don't know that it matters but it is certainly noticeable when one or two are not of the same colour temperature...*&^% forget what the other number on the label is called, also having to do with colour but do recall that the T-8 have that number higher than the T-12 and they do not look exactly the same.
The other thing we are now having to do is try to get the one closest to the LED pots that have started to be installed and to me, they are a bit bluer.

For me personally, I want a light that allows the items natural colour to be as accurate as possible (if that makes any sense)

jlevie
06-17-2014, 07:03 PM
Daylight balance bulbs will be the most effective. Thousands of years of evolution have tuned human eyes to work most effectively with light that is heavily yellow (i.e., sunlight). We have the most visual acuity with that color balance. The other factor is intensity and the more light the better. In most cases shop lighting is far lower than is ideal, even with the correct color balance. Four tube by 48" fixtures on 3-4' centers only comes close to natural daylight intensity.

danlb
06-17-2014, 07:12 PM
The "CRI" is a measure of how true colors will appear when compared to a light with a tungstun filament.

Daylight is actually quite blue. Look up and you will see a huge blue filter.

It is possible to get custom lighting by combining two different lights to get a tint in between.

Dan

KJ1I
06-17-2014, 07:31 PM
I replaced all the bulbs in the (19 2-lamp fixtures) shop with Phillips Cool White Supremes (42267-5 F40T12CW/S from Home Depot). I find the color temperature best for my 64 year old eyes. I, too, find the "Daylight" bulbs to be too blue.

Gary Paine
06-17-2014, 07:43 PM
It's getting time to replace .... tubes are at least 15 years old. I think there is better stuff out there...
.....................

I'm wondering how many years you are wanting to get on a light bulb?:confused:

firbikrhd1
06-17-2014, 08:40 PM
It is my understanding that T 12s are on their way out. Old technology, efficiency and flickering when cold are all factors but I'm certain there are others. Since you are changing out anyway you might want to consider changing over to T8s. The fixtures can remain in place but the tombstones and ballasts need to be replaced. I believe that 48" T8 bulbs are much less expensive than T 12s.
Currently I'm building a new home with a shop in the basement and went with T8, 8' fixtures with 4 48" bulbs in each. The light is brighter than the 8' double tube T12s in my current shop, there is no hum and no flicker when cold. T8s also reportedly have a longer bulb life. We'll see.

lakeside53
06-17-2014, 09:16 PM
Rip out the T-12 ballasts, replace with T8 ballasts, install T8 Bulbs. Done.

I recently did this in my shop. I bought quality T8 Ballasts on ebay by the box for about $8 each. Way better light, no hum and no flicker. Oh.. they start up when the shop is 38 degrees!

ahidley
06-17-2014, 11:38 PM
I'm in my shop a lot at night. I have 4 footers from lowes. I was getting head aches. So I changed every other bulb with a full spectrum bulb. The head aches are gone

JoeLee
06-18-2014, 08:47 AM
I guess everyone has a different opinion when it comes to lighting. I'm not complaining about getting 15 years out of most of these bulbs that I paid $1 for when they were on sale. It's just that there are better bulbs out there now than there were when I bought these.
I wasn't aware that you could buy replacement ballasts and sockets for the T-8's that would fit in the T-12 drop in fixtures. At what cost???
The T-8 fixtures I priced were about $100 each or more and I'm not sure weather that came with bulbs or not.
I guess the full spectrum bulb will be the best choice.
I'm not concerned so much about the color temp. but just used it for comparison purposes. I went through this when I replaced the incandescent bulbs in my machine lamps with the new CFL's and found that the 6500K CFL was actually too blue and very uncomfortable to work under so I went with the lower 5500K I think it was.
My T-12's never flicker even at 50 degrees which is about the coldest the shop gets in the winter. The 8 footers over the work bench do flicker for a few minutes, not sure why, must be the ballasts.

JL.................

garagemark
06-18-2014, 09:48 AM
If you decide on a change to T-8s, ther is no real need to replace the tombstones. T-8 and T12 are the identical pin size. The ballast will require a re-wire of the existing tombstones, but it is all done at the ballast (no need to remove the tombstones).

Just a heads up.

Rosco-P
06-18-2014, 10:23 AM
The "CRI" is a measure of how true colors will appear when compared to a light with a tungsten filament.

Daylight is actually quite blue. Look up and you will see a huge blue filter.

It is possible to get custom lighting by combining two different lights to get a tint in between.

Dan

Think not.... CRI (color rendition index) is a measure of how accurately colors appear under a light source as compared to sunlight, 6500 degrees Kelvin. LEDs have a long way to go. Tubes made by Kino are as close as you can get, but impractical for shop or home use.

dian
06-18-2014, 10:48 AM
sunlight is 6500 kelvin. why do we find that uncomfortable?

Rosco-P
06-18-2014, 10:52 AM
sunlight is 6500 kelvin. why do we find that uncomfortable?

Why do we spend extra money and risk leaking roofs to install skylight if sunlight is uncomfortable to be under?

Likely as not the CFL had a poor CRI and one or more color spikes in its output spectrum.

lakeside53
06-18-2014, 10:59 AM
I wasn't aware that you could buy replacement ballasts and sockets for the T-8's that would fit in the T-12 drop in fixtures. At what cost???
The T-8 fixtures I priced were about $100 each or more and I'm not sure weather that came with bulbs or not..

JL.................



I paid $8 each on Ebay. Here's some for $10 or "offer" (many other to choose)
http://www.ebay.com/itm/Sylvania-Ballast-Quicktronic-49945-120-227V-QTP-3x32t8-UNV-ISN-SC-/121362968986?pt=LH_DefaultDomain_0&hash=item1c41cbf19a

Search by brand to reduce the clutter.

$13 to $20 at Home depot (2 lamp fixtures) http://www.homedepot.com/s/t8%2520ballast?NCNI-5

Takes about 5 minute per fixture.

Another reason to change from T12 with magnetic ballasts is that they are inefficient (power robbing) pigs.

mattthemuppet
06-18-2014, 11:14 AM
because LEDs and CFLs use blue or UV light to excite a phosphor, they all have a lot more blue in their output for any given colour temperature. The higher the colour temp, the thinner the phosphor (at least for LEDs) and the cooler/ bluer the light. I don't have much experience with CFLs other than in standard sockets, but I've played with a lot of LEDs and you can get pretty much whatever CRI and colour temp you want, although not always at the same time :) I have a couple of lights with 92+CRI LEDs that bring out colours just the same as in daylight - that's a more relevant use for CRI. Not so much how it looks like sunlight, but how colours look under its light compared to sunlight. Eg. you really don't want to be diffusing a nuclear bomb at night using a 6500K LED, especially if they use a lot of green, cyan and blue wires :D

I have 4000-4500K high CRI LEDs in my shop/ machine/ head lights and I like them a great deal. Clearer than the 3300K CFL, no issues in the winter, easy on the eyes. I have 5000K med CRI LEDs in my mountainbiking lights and the improvement in contrast over the 6500K LEDs I had before is enormous. Might not sound like much, but distinguishing between a pile of leaves and a pile of roots can make a big difference.

If you're interested in a fun project, I'd personally recommend making your own LED shop lights. They're cheap, easy to make and you fiddle with optics/ output until you get what you want. The raw lumen count will be lower than an equivalent CFL, but it's all going to be pointing where you want it.

JoeLee
06-18-2014, 11:40 AM
If you decide on a change to T-8s, ther is no real need to replace the tombstones. T-8 and T12 are the identical pin size. The ballast will require a re-wire of the existing tombstones, but it is all done at the ballast (no need to remove the tombstones).

Just a heads up.I wasn't aware of that...... I've seen the T-8's in other shops and couldn't believe how bright they were.
Lakeside, thanks for the info on the ballasts.

JL................

justanengineer
06-18-2014, 01:59 PM
I wasn't aware that you could buy replacement ballasts and sockets for the T-8's that would fit in the T-12 drop in fixtures. At what cost???
The T-8 fixtures I priced were about $100 each or more and I'm not sure weather that came with bulbs or not.

I put a couple of these in my garage two summers ago. They were on sale for $25 each, at the same time Lowes had a sale on bulbs for ~$1.50 each. At least from what Ive seen, changing only the ballasts isnt worth the money as decent ballasts sell for $10-25 each, dont have a decent warranty, and at least for non-recessed lighting take more time to replace.
http://www.menards.com/main/p-2259111-c-6353.htm

I find that the relative brightness and comfort of the room depends on a lot more than the bulb color temp, and many folks set themselves up for disaster with window placement and/or room color. Personally, Im very sensitive to bright lights and severe color contrasts, so for me its much more comfortable to have natural gray, green, or brown colored walls with a matte finish to provide less contrast with the machinery and parts compared to having white, shiny walls. My current garage for example has wood paneling covering 100% of the walls and ceiling, with the brightest T8s I can buy its very easy on the eyes. The only downside, its very dark in there without the lights.

SteveF
06-18-2014, 03:39 PM
sunlight is 6500 kelvin. why do we find that uncomfortable?

No, sunlight is about 5500K, 6500K is daylight or the color of the sky on a clear day.

Put those two bulbs side by side and the 6500K bulb looks bluish.

Why that is uncomfortable, I don't know but when I put 6500K bulbs in my shop the glare was definitely noticeable and they got swapped out.

Steve