How much is really "enough"?

[Hottrod]

Hi all, my project detailed elsewhere on GJ is proceeding well, and it is time to order the lights for my 34'x22' garage, which will be used primarily for detailing and basic mechanical and small project work.

The flat drywall ceiling is to be painted bright white, as are the walls and the floor will be a white epoxy floor from LegacyIndustrial or a white HDSpartacote finish, so as to maximise the light in the area. The garage doors are of frosted glass, which will let in some daylight and have the advantage that at night with the doors open, the ceiling lights are not blocked out.

As per the drawing below, my plans call for 3 banks of 3 Lithonia MS8's arranged in a North-South orientation, each of which have 3x32W T8 fluorescent tubes - thus I'd have 27 32W T8's in all, and they'll be controlled by two switches, so that I can have have a choice in how many are turned on at once.

The spec sheet for the fixture can be seen here, and for those of you that can assist in deciphering it, the photometric report is here.

As an aside, I know the T8 and T5 issue has been discussed on GJ and elsewhere extensively, but due to the inexpensive electricity costs here the T8's seem to be the sensible choice as it would take a long time to make the T5's worth the extra cost for me.

Alternatives to the suggested configuration include: increasing/reducing the number of these fixtures, or perhaps supplimenting them (or replacing them altogether) with downlighters fitted with retrofit LED parabolics, like the ones seen here:

I'm way out of my depth here and would appreciate the collective wisdom of the forum on the adequacy of what has been spec'd, and whether anyone thinks that adjusting the orientation of the fixtures to an East-West direction would be preferable.

Thx!

 

[pattenp]

The only thing I would add is 3-way switches for the garage lights at the front by the garage door for if you enter on foot through the garage door. That way you don't have to walk to the back of the garage to turn on the lights.

 

[PRH44]

I assume you are wanting even distribution across an open work area. If so I would recommend using the wide distribution (WD) optical on this fixture. Your photo metrics are based on a narrow distribution (ND) optics.

 

[PRH44]

Unless you are set on the louver appearance. I would use the blank option. Dust will build on the louver making it a pain to clean each cell. With no louver you can dust the lamps easily in place. You can remove and clean them much easier also.

The 10% up light option with the white ceiling would be a very cool look no shadows or cavern feel. You would reflect most of it back down. If you want to strangle every lumen out of your fixture and have maximum candela at the floor, then I would omit the up light.

 

[Gary S]

How much is enough? Only you can answer that question. Are you 20 or are you 60? Can you see in the dark, or are you blind?

Years ago I found that the amount of lighting I needed for my aging eyes was far too much for my much younger Son's to work with. I backed my vehicles out in the driveway to work in the light of the sun because I couldn't see in my garage. My Son's worked inside with their vehicles because the sun blinded them.

My welding helmet was too dark for me and too bright for them.

You are asking the wrong people this question. Ask yourself and get it right for you.

 

[olytdi]

I'm in my 50's with what I think are "normal" eyes. I installed total of 10 eight foot fixtures each with four tubes situated in two banks like you mention. I configured mine in a sort of square pattern in a 28x28 ft building. These are 11 ft up. I find the amount of light to be adequate but frequently need an additional drop light for close-up work. I don't think you can have too much light -- especially since you can turn some off. But then, I really like a super well lit space. Oh, and I painted all of the walls white and have white vinyl insulation on the ceiling. A white interior really really helps in the brightness department. I was afraid it would be sterile but once everything is installed and the space is furnished, it's great.

 

[Charles (in GA)]

Unless I missed it, how high is the ceiling? Do you intend to mount the lights directly to the ceiling, or have them hanging down some distance?

Charles

 

[Hottrod]

Unless I missed it, how high is the ceiling? Do you intend to mount the lights directly to the ceiling, or have them hanging down some distance?

Charles

Hi Charles, the internal (finished) height is 10', and I was hoping to have the lights fixed up against the ceiling, or perhaps even recessed, in order to give a really clean look.

 

[Charles (in GA)]

Hi Charles, the internal (finished) height is 10', and I was hoping to have the lights fixed up against the ceiling, or perhaps even recessed, in order to give a really clean look.

I assume you are wanting even distribution across an open work area. If so I would recommend using the wide distribution (WD) optical on this fixture. Your photo metrics are based on a narrow distribution (ND) optics.

At ten foot of height, indeed, he needs all the light distribution he can get, or there will be hot spots and dark spots.

Recessing the lights is a lot of work (to me it is at least) and these are designed to be either surface mounted or suspended. They are not a type that would recess easily and you could have heat problems if they had insulation on top of them.

At ten foot height, you might want to chose the optional WGMS8Z 4' wire guard, zinc coated, that can be attached for protection. Real easy to swing something long up into them while you are working.

Charles

 

[Hottrod]

At ten foot of height, indeed, he needs all the light distribution he can get, or there will be hot spots and dark spots.

Recessing the lights is a lot of work (to me it is at least) and these are designed to be either surface mounted or suspended. They are not a type that would recess easily and you could have heat problems if they had insulation on top of them.

At ten foot height, you might want to chose the optional WGMS8Z 4' wire guard, zinc coated, that can be attached for protection. Real easy to swing something long up into them while you are working.

Charles

Thanks for the input Charles - I take the point about using the WD version of any fixture, many thanks for that! If we went with a recessed version I would opt for a fixture that was designed as such, probably from the same manufacturer (unless someone has a better suggestion!).

 

[CRE Neal]

I am 39 yrs old, I work on small engines and do small parts machining... my shop is 22x28 with 10' ceiling height...I run 10 x 4' , 2 bulb strip T5HO 55 watt 5000K lights...and I have 2 par 38 LED, 18 watt , 5000K, 25 degree beam angle spotlights above my detail bench and my lathe..... I would consider my lighting to be quite good.....most excellent to work under day to day....especially if you are working on small parts...