Preferred lamp color/temp

[chris kennedy]

I'm reviewing submittals for a manufacturing facility I'm working on and had to groan when I see the EE speced 3500k T5HO's in my high-bays. (4 lamp). I'm partial to 5000k for this and most applications, maybe because my eyes are going south, but the 5000's have more of a "daylight" look to me.

What is your preference?
Why do EE seem to always spec 3000 and 3500?

 

[gar]

110619-1417 EDT

In between. I tend to use Cool White and have for a long time. This seems to be classified as 4100. My wife likes plain incandescent, and dislikes fluorescent.

.

 

[mivey]

110619-1417 EDT

In between. I tend to use Cool White and have for a long time. This seems to be classified as 4100. My wife likes plain incandescent, and dislikes fluorescent.

.

I did not care for the fluorescent in a home until they started making high CRI lamps. Now I prefer the brighter light and truer colors in the task areas like kitchen, laundry, etc.

 

[chris kennedy]

I did not care for the fluorescent in a home until they started making high CRI lamps. Now I prefer the brighter light and truer colors in the task areas like kitchen, laundry, etc.

I have never installed them but the specs also list a 6500k. I would like to see what those look like.

 

[Chamuit]

With what you are doing definitely the 5000K's.

 

[220/221]

35K, no question about it.


I absolutely HATE the color rendition on 4100K and above.

 

[big john]

I have never installed them but the specs also list a 6500k. I would like to see what those look like.

That's what I use in our plants. The light is almost indistinguishable from true daylight, and has fantastic color rendering, but I think it has a higher UV component, makes it a little harsh.

-John

 

[stevebea]

I'll cast my vote with Gar. I prefer by far the 4100k.:thumbsup:

 

[Electric-Light]

"that's how we've always done it" is one of the reasons. Ignorance is another. I'm not sure if there's been a change in user preference or simple awareness.

Ask around and you'll find enough people in trades who are not aware that fluorescent lamps come in six basic CCTs in two rendition ranges RE70 & RE80 and additional specialized specification lamps.

Internationally, 5,000 & 6,500K are very common. In, N America, traditionally almost all commercial lighting was 4100/CW/~60CRI and the other alternative was 3000K/WW/~50CRI

Most lamps now are available in 3,000,3,500 & 4,100 and if you stay with one of these three, then you'll know just about every size and shape will be available.

I believe 5,000K is becoming more well known and gaining acceptance here in both consumer & commercial sectors as 5000K is now available in U bent, T5, 55W twin, etc from big 3. 6,500K is a hit and miss. For whatever reason, pin-based CFLs are not available in 5,000K unless you look at generic brands, so seamless integration of CFL fixtures with linear fixtures maybe an obstacle.




RE850 CFLs been around for a long time, but it wasn't until a few years ago that they became commonly available in big box stores in the North American market.

I personally think 6,500K is too blue and even if the customer likes it, I wouldn't spec them, because the future availability of replacement lamps remain uncertain at this point.

Philips is dropping 32W T8 6,500K as it falls something like 75 lumens to meet EISA requirements. GE ones are not passing. The only passing 6500K that I'm aware of is the OSI Octron XPS 865. RE80 5000K lamps from all three currently meet the efficacy requirements for July 2012.

 

[iMuse97]

I've installed some 6500K "daylight" T8 lamps in a fabrication shop and the welders, fabricators, (and owner) love it. He has had me put some of them in his own office as well.

Personally I preferred 4100K esp. in office areas. I'm OK with 5000-6500K in the fab. shop areas., but I cannot think of any areas where I really like the 3500K.

 

[Electric-Light]

but I cannot think of any areas where I really like the 3500K.

The Government uses a huge amount of lamps and 835 is a fairly common specification. RFQs come in. You use materials that meet materials that all of their shalls or get left out as non-responsive or get called out by competing bidders to get you off the list.

The purchasing specification writers don't necessarily know what they're doing and are sometimes influenced by manufacturers sales reps. You see the lamp manufacturers playing games with 1-2 CRI points, or some insignificant just so they don't get left out of the game.

Here's an obvious Philips exclusivity favored requirements from a public purchasing specification of a Tennessee institution. :lol:

A. General: Provide lamps to match the requirements of the luminaire and ballast in
which they are installed. Subject to compliance with these specifications,
provide fluorescent lamp from one of the following manufacturers:
General Electric
Phillips
Sylvania
B. Standard T8 fluorescent lamps shall be medium bi-pin lamps suitable for instant
start or rapid start ballasts. Lamps shall be in lengths as required for the fixture
installation and shall be 3500 degree Kelvin color temperature, 86 color rendering
index minimum, 20,000 hour rated average life. Mean rating for a 4-foot,
standard output lamp shall be 2800 lumens. All T8 style fluorescent lamps shall
be low Mercury and Toxicity Characteristic Leaching Procedure (TCLP)
compliant, and shall have green endcaps to demonstrate compliance.

You can't not use Philips and meet both requirements. Brochures often have "architectural specifications" written in that manner in a way that favors them in a hope that someone at purchasing will just copy and paste and change out a few words.

Since Philips green end caps are Philips' trademark, that spec writer effectively locked their option to Philips exclusive without blatantly/intentionally violating sole supplier rule.

 

[BJ Conner]

SAD Syndrome

SAD Syndrome

6500 K lights are benificial in treating Seasonal affective disorder (SAD) syndrome. There is lots of research on this. A lot of the research was done in Canada and northern Europe where winter days are short.
IF you google SAD syndrome and Light thearpy you'll get more than engough to read. Suicides and alcoholism are higher in northern latitudes.
I haven't read up on putting them in general buildings but some where and with a second shift and maby post offices would be canidates.
If I was redoing a house I'de consider them in Bathrooms and the breakfast area. :weeping:
http://en.wikipedia.org/wiki/Seasonal_affective_disorder

 

[steve66]

I normally spec 3500 or 4100, but mostly because that's what the architects and interior designers seem to like. Paint and other furnishings definately look different under different color lamps. The yellow tones from 3500K fixtures seem to make people and skin tones look more natural.

I recently saw a dentist's office that had 6000 or 6500K lamps installed in RT5 fixtures. The dentist really seemed to like it, and he said it was great for the type of work they did. But the lamps and fixtures were very blue, and I thought it really looked like a morgue.

Edit: Maybe the 4100 K should have been an option too?

 

[Electric-Light]

6500 K lights are benificial in treating Seasonal affective disorder (SAD) syndrome. There is lots of research on this. A lot of the research was done in Canada and northern Europe where winter days are short.

They're used in special fixtures which is basically a light panel with 6500K CFLs you look into for this specific purpose. Our mind compensates white balance, but latitude is limited. If you sit under 5,000K all day it will look white. If you then move to a room lit by 4,100K it will look yellow.

If you sit in a room lit by incandescent, the "yellowness" never goes away, as its outside the range of white balance correction.

You can adapt to 5,000K after couple minutes. 6500K may provide persistent "blueness".

IF you google SAD syndrome and Light thearpy you'll get more than engough to read. Suicides and alcoholism are higher in northern latitudes.

If you compared suicide/alcoholism between Compton, CA and Irvine CA, I don't think they'll look quite the same. Without a full data, its quite possible that Compton equivalent sample was used for northern latitude and some affluent suburb was used for southern latitude, or however it is to promote the sale of product.

Paint and other furnishings definately look different under different color lamps. The yellow tones from 3500K fixtures seem to make people and skin tones look more natural.

Of course they look different, so much that CRI is basically only useful for comparing light with similar CCT. During the day, would one look more natural in skylight lit kitchen or the tungsten lit bathroom? I don't know. It's all about preference.

I recently saw a dentist's office that had 6000 or 6500K lamps installed in RT5 fixtures. The dentist really seemed to like it, and he said it was great for the type of work they did. But the lamps and fixtures were very blue, and I thought it really looked like a morgue.

Edit: Maybe the 4100 K should have been an option too?

The intensity affects perception too. High CCT lamps tend to produce unpleasant perception in low illumination level. You'll see this when you're walking/driving around in a rural area with no street lights and you see someone's 6500K CFL porch light spilling onto the sidewalk.

You don't experience this effect at 6500K if its at a MUCH higher FC value, such as being outside on an overcast day.

 

[iwire]

I'm reviewing submittals for a manufacturing facility I'm working on and had to groan when I see the EE speced 3500k T5HO's in my high-bays. (4 lamp). I'm partial to 5000k for this and most applications, maybe because my eyes are going south, but the 5000's have more of a "daylight" look to me.

What is your preference?
Why do EE seem to always spec 3000 and 3500?

I have no preference, it is not my job to have a preference. I install what the EE has asked for. To me this is crossing the line from trying to do a good job to trying to design the job. (Not PWI but do I still sound like your boss?)

 

[chris kennedy]

I have no preference

Really? Lets say the internet gets killed in some crazy war between the trolls and the spammers and you take up knitting. Your turning your garage into the ultimate knitting cave. You chose florescents, now chose the lamp.

I install what the EE has asked for. To me this is crossing the line from trying to do a good job to trying to design the job.

I'm sure you have heard me say many times "We don't pick-em, we just stick-em". I install whatever is speced and if we can sell them a lamp up-grade in the future, well thats gravy.

(Not PWI but do I still sound like your boss?)

Only when you tell me how slow I am.