having trouble choosing color temp (kelvin). does sunlight = blue?

[SUPERFORD]

Hi everybody, so I'm going to pick up my garage lighting fixtures today for installation in two days. So I need some help asap.

I've done some research here and elsewhere and still need help in choosing a "color temperature" or kelvin rating.

I'm installing about 14 dual bulb 8' T8 HO fixtures in about 1050sqft space.

I want bright lighting. I want to be able to see well in the shop under any condition or during any task.

It would seem to me that "daylight" is best, but this means going 5000+ kelvin rating.

for some reason, everything I read says that this will be on the "blue" end of the spectrum.

I don't equate sunlight with "blue" light. I don't understand & I don't "think" that I want blue light in my garage.

also I understand the higher CRI the better 90+

I understand that this may be a subjective number (like your sleep number bed ?) and the ideal color for you might not be the ideal color for me...

But I just don't want to purchase 28 of the "wrong" color bulbs!

help.

Thanks,
Chris

 

[darkk]

Don't let the*blue* nomenclature scare you. Your room won't be blue in color. That's just how it's described. Daylight (5000k) bulbs are really nice to work in. They are just more expensive to buy. We have 32 4ft. twin bulb T8 fixtures with daylight bulbs for our 30x30x12 garage. With all the lights on, You could probably see us from space...hahaha! They are not installed at the moment because we are in the end stages of construction, but we tested them all on the floor when we got them. Needed to be sure they all worked.

 

[J Persons]

Just bought two twin packs of Phillips 6500K bulbs from Home Depot. They put out a nice white light, but not so bright as to hurt your eyes.

 

[Cryptic1911]

6500k's usually have a slight blue tint to them, not really noticable if you're in the room, but from a distance you can see the color a bit if you're looking into the area with them. I'd stick with 5000k-5500k bulbs as those are basically pure white light (right before it gets to the blueish hue). Get as high a lumen output as you can (more lumens = brighter). Also, the CRI isn't critical for everyone, so it depends what you are going to be doing. If you're just working on cars, then I wouldn't worry as much, but if you're spraying paint and trying to color match, then the CRI (Color rendering index) is going to be very important. 85 CRI is about where the cutoff is for price, so much higher than that and the bulbs get pretty pricy. One tip I'd suggest is to run the lights in rectangles around where the vehicles will go, and not over the top as that will create shadows. If you run them along the sides and inbetween, you'll get good light coverage all the way down the sides, and over the top as well

 

[Frank The Plumber]

I used to really know this well. Bred a few types of corals and did a lot of marine aquarium stuff.
Best color came off of grow bulbs gave a nice cool blue appearance. While a day bulb gave a yellow color.
You can mix them to get a custom temperature of light.

 

[MoonRise]

Chris,

The term 'daylight' in fluorescent bulbs/tubes can refer to the "color temperature" of the light emitted OR to the relatively high CRI of the light emitted OR to a combination of color temperature AND a relatively high CRI. Sometimes the term 'daylight' also refers to so-called 'full-spectrum' tubes (generally a good thing there).

High CRI = a good spread of emitted light frequencies across the spectrum, and not just a few wavelengths spread out all over the place. Good thing.

Having a color temperature in the 5000K to 6500K range is usually pretty good and most of the time the eyes and brain can see that light and call it "white". Sort of like auto white balance on a digital camera.

For really color-critical tasks, the exact color temperature of the light may matter. For most everyday tasks, 'close' is usually good enough.

As to the 'blue' designation of higher color temperature light sources, as I mentioned, most of the time the eyes/brain can see that light and call it 'white' if the spectrum/CRI is broad enough. No one's brain can remap the almost single wavelength low CRI light from a low-pressure sodium lamp and see it as 'white' though.

And the 'blue' is also a bit of a relative thing. If there is only one light 'color' that is close-enough to 'white', then the eyes/brain do the auto-white balance thing and you 'see' white light.

But if there are multiple light sources with varying color temperatures, then the 'auto-correct' of the eyes/brain usually can't line all those color temperatures up and most people can then see actual color differences between the light sources. Quick example: In sunlight, turn on an ordinary incandescent light bulb. The same one that you see/think is 'white' all by itself in a dark(ened) room usually looks really-really yellow/orange when you see it in sunlight/daylight.

+99 on getting some 'good' CRI bulbs/tubes. As mentioned, 85+ is usually pretty good for the CRI, but getting 90 or better usually is more specialized and $$$.

More tips/hints.

Spread the light out, and put the fixtures on multiple separate switches. Sometimes you want the light coming from a certain direction, and sometimes you want the light evenly spread and non-directional.

For 'precision' type work, the usual standard is 100+ to 150 lumens/ft2 at the working level. For your 1050 ft2 shop area, that means 105,000 to 157,500 lumens total. With 14 fixtures, that means you need ~ 11,250 lumens from each fixture. Most fixtures give maybe 80% of the bulb/tube lumen 'rating' actually getting out and being 'useful'. So divide by 0.80 gives 14,063 lumens from each fixture based on the bulb/tube 'rating'. (obtw, the 'lifetime' rating on most fluorescent tubes is based on when the light output drops to 50% of the original 'spec' rating, so don't think you will really get full-power light output for those 20,000 hours or whatever the tube is 'rated' for. Yes the tube will still light up, but the light coming out may only be 1/2 of what it was originally and at 'spec'!)

8ft fluorescent tubes can run from ~5500 lumens (initially) to ~12,000-14,000 lumens (initially) (F96T12 VHO tubes). But those VHO tubes run a poor CRI of ~60.

Hmmm, some GE F96T8/SPX50/HO tubes spec at 5000K and 86 CRI and 8200 (initial) lumens. Two of those tubes (or equivalent) in each of your 14 fixtures will get you pretty much right at the target light intensity of 150 lumens/ft2. Good to go there.

 

[nate379]

I have 4200k in my garage and they are about perfect. Almost too blue, but not too horrible. I had 3800 before and those weren't bad either.
I tried higher k ones in a kitchen fixture and it was just too "unpure" of light, almost needed sunglasses.

I have about 85 lumens per sq ft in my garage and it's more than enough light. I may end up putting a clicker chain on one or two fixtures even.

 

[Tom McDermott]

Hi Chris,

You'll get a lot of opinions on which color is better, and everyone's right ! (well, for themselves). You might be happiest to look for yourself before buying. Around here, the local electrical supply place, HD, and perhaps Lowe's have the different color temperature fluorescent lights on display. You can look and see which you prefer.

-- Tom

 

[haugy]

These are 5000k T-5 high bays. 4 of them total with 4 bulbs each. 40x30 shop.

They are plenty bright, so bright even that now when I'm detailing I can see every blemish, missed spot, or imperfection. My detailing work just got pushed to be better. Great.

They have no blue that I can see. Very clean bright white. I'm very pleased with them. I do have traditional halogens along the walls for low light if I need it. But they are definitely a no joke bright. If you want to work, these are great. If you want somewhere to hang out, these will be a little too bright in my opinion.

 

[Zengineer]

4100K-5000K will be the most pleasant light for most people. I wouldn't go off either end of that range for general garage lighting.

 

[gatchel]

4100K-5000K will be the most pleasant light for most people. I wouldn't go off either end of that range for general garage lighting.

I'll also have to agree.

I use 4100K in my garage.

 

[rockchucker]

I use the T-5's and use an alternating bulb Blue-Red Spectrum. Best of both worlds IMHO.

 

[ket-tek]

I needed 36 4' bulbs for my garage and didn't want to buy that many and not like it, so I bought a 2 pack of each 4100, 5000, and 6500 to try first.

The 6500 was outrageous on my eyes, I completely hated it. It was so artificial and was very distracting. The 5000 weren't bad but still seemed a bit to much like an office/school/hospital, I could have lived with it, but the 4100 were very nice to the eye and gave a more natural atmosphere.

They were all Philips ALTO II bulbs, and the 4100 actually had a higher lumen rating and better cri rating than the other two temps. So although the 6500 was more blinding and falsely seemed brighter the 4100 actually put out more light.

I filled it up with all 4100k and love it. If anything mixing a few 5000's in with the 4100's may be decent to try out.

Like menitioned above, peoples eye's and perception of light can vary so I suggest try a couple different ones before buying that many bulbs.

 

[79mudbugg]

they way people should start lookin at it is switches! u can dual ballast a light and #1 be more cost saving then if its one of those late nights with a few colds one and havin problems seein flip the other 3 swithes on!

 

[east_tn_emc]

Go to Lowes or HD and make your way over to the lightbulb section. Every one I have been in has had a display with a number of different florescent bulbs turned on and labeled as to their temperature. You can compare 4100, 5000, 6500, etc and see which is more pleasing to you.

I would also suggest going over to the paint section and pick up a couple of paint color cards and take them outside into the sunlight and get an idea in your mind of what they look like, and then take them over to the lightbulb display and hold them under the different lights and see which one make them look most pleasing to you.

I found that just looking at the light produced by the 6500K lights made my eyes hurt (but my eyes have always been sensitive to bright sunlight) and I found the 5000K worked best for me. Everyone will come to a different conclusion, and for different reasons, as to which color temp is best.

 

[Falcon67]

I used 6500K. They may take a bit of getting used to because they are rather bright. At first, they may seem to be a bit on the blue side but it's not much. Working under them is real nice. I don't care for shadows. Buy them by the 10 packs at Lowes or HD and they come in at around $2.50 a bulb.

 

[lwlobo]

In the garage I like the Bright White, or 5000k. In the house it's too "cold" or a bit blue. I can't stand Daylight, or 6500k, anywhere.

I bought Phillips 4ft T8 bulbs at HD last weekend, 10 pack for $15, or $1.50/bulb. Seemed very good, especially since the 2 packs were $7, and I needed 5 bulbs.

I know of a factory that just installed new fluorescents (replacing sodium) and they used 1000's of 5000k bulbs. 5000k is nice light to work in.

 

[Zengineer]

I just did two 20,000sqft commercial garages with 5000K also. I feel very strongly that it's the best choice after finishing those two spaces. Feedback from more than 50 maintenance staff was 100% positive.

 

[Steevo]

I would have used all 5000k tubes in my shop, if I could have found them in bulk pack boxes at reasonable prices. Instead, I did all but the fixtures over workbenches with 4100k tubes, because they are CHEAP in a 25-pack. Over the workbenches, I used 5000k tubes.

What can I say? I am a cheapskate.

 

[BillK]

These are 5000k T-5 high bays. 4 of them total with 4 bulbs each. 40x30 shop.

Just want to make sure I have this right . . . . that amount of light is from a total of 16 T-5 bulbs ?? If so that is pretty amazing

The reason I ask is that our local utility is giving some pretty decent rebates for switching to T-8 or T-5 in commercial buildings. My shop really could use some more light so I am looking at options. Shop is 30 x 60 with 14 ft cielings so it may need a few more fixtures.

Thanks,