How do I figure lighting for my shop?

I am looking for info on how to figure how many light fixtures I need.

Shop info: 50' wide x 60 ' deep x 14' wall height. Walls and ceiling covered with galvalume metal. I would hang all lights at the 14' level.

I am looking at 4 tube flourescent fixture t5 HO using the 5000k range bulbs. But will consider other fixtures based on recommendations.

I have read that you should have a fixture for every 250 sq ft, etc. Is there a web site or ? that shows the pattern these fixtures cover, how the height affects coverage, brightness of interior walls, etc. that affects this decision?

How is you shop setup and does it provide enough light? I'm 65, so the more light the better as far as I'm concerned but I also use machine specific lights.

Appreciate your input. Gary R.

Call the power company.

Also see if they have any programs to help pay for it.

Im in a 32x50x17high with six of the 6 bulb t-6? fixtures and it is very bright. six bulb fixtures can be wired to two switches so you can turn on 2,4 or all 6 bulbs.

I have this setup in my shop.

-"house lights" which are single A-base (used to be porcelain, now plastic) fixtures. Populated by 22W (100W equivalent) CFL bulbs. Basically so I can go in and walk around and not break my teeth. In a 25 x 25ft bay I think there's 8 of those.

- T5HO x 4 bulb fixtures, bought on Amazon, around $110 IIRC free shipping including the bulbs. I have 2 of these at various machines and workbenches. Basically 1 of these can service 2 machines. About to pull the trigger on 2 more.

Depending on what I'm going, I use the house lights only or both, just trying to conserve where I can. The 8 x 22W is 150W, about 1 amp draw @120vac, each T5HO is 54 x 4 = 216W, roughly 2A on 120vac. So those draw energy faster, but well worth it where needed.

Just sasying you might consider a hybrid system and not have 8-10 x 4bulb fixtures going all of the time. You can easily approach 15-20A draw for just lighting.

Another factor is what you use the shop for..personal use nights and weekends might be better off with more CFLs, if its a full-time profit-driven business with employees then lighting cost is probably fairly slim as far as utilities go.

The standard is ASHRAE 90.1. Great standard if you got lots of money or are working with somebody else that has money. Government buildings will comply with this.

Here's a great website: Illuminance - Recommended Light Levels

If you look at the tables, for a shop, you need somewhere between 1,000 to 10,000 lumen/m2. That gets expensive. I'm a big fan of task lighting also. But, I'm not an old man, I'm only 62. IMO, figure on the low end, around 1,000 lumen/m2.

I run T8 bulbs in my shop. 40 of them at about 3,000 lumens each @ 10'. Shop is roughly 100 m2. So, I'm at about 1,200 to 1,500 lumen/M2. That doesn't include the lights on my mill, grinder, saw, lathe and bench.
JR

1,000 watts per 25 SQ FT... Oh that's for indoor gardening.

8 400watt matal halides will light you up good and can hang floros over select machines and benches for additional light.

Im Kind of an expert at lighting and ventilation.

Just went through and updated the lighting in my 24 x30 shop. It had six 8' dual tube T12 fixtures I put in almost 40 years ago, most were dying or dead. I wanted to go with LED's and tried to emulate the lighting of an LED re-lamped SevenElevn which had suburb lighting. I managed to ID the troffers used in the SevenEleven but at around $400 each it just didn't pencil out, even for bragging rights. Even tried to make my own with some Cree emitters, the prototype had the light I needed but the cost was still too expensive.

I ended up modifying my existing two tube T12 fixtures to take four T8 tubes. Its been in about 6 months now, the lighting is great and as good as the SevenEleven, better CRI than my LED prototype, and double the LUX I had with the T12's. The key with the T8's is to get the correct tubes and ballasts.

I used a 500K broad spectrum 900 series phosphor tube with a high lumen output from Litetronics and a matching GE UltraMaxH ballast with a ballast factor of 1.18. The ballast factor is important parameter to look for and determines the tube's drive current and light output. A lot of ballasts are sold as energy savers and have low ballast factors (like .87) they only drive the bulb at 87% of its rating, yes it saves energy but at the cost of light output. My GE UltraMaxH drives the tubes at 118% for more light. I am getting about 1000 LUX at 36" off the floor total power is 909W and if I want to save energy I turn several off. The 900 series phosphor is a nice broad spectrum brilliant white with a CRI of 90. I ended up with 24 T8 tubes arranged in three strings parallel to the 24' wall, one in the center, two midway to the wall on each side of center. The total cost for the bulbs, new ballasts and new sockets with shipping was around $300. This was less than one LED fixture. Glad I did the T8 and not the LED's, light is great, instant on, on hum or flickering, very happy with the results.

Not sure the T5 are that better, there is a significant cost premium over the T8 in bulbs and fixtures. Apparently it's a little tricky to compare T8 vs T5's because they use different measurement and specification techniques.

You can buy in import LUX meter off Ebay for a few bucks, not sure how accurate they are but adequate for comparisons.

For those who don't know the number after the T is the tube diameter in 1/8 of an inch. T5 = 5/8" etc. You really have to look at the specific bulb specification sheet to see how much light, the spectrum and life time delivered from the tube.

Got everyting at 1000bulbs.com
Tubes: Litetronics L-359 F32T8CB50
Ballast: GE UltraMax H part number 71723 (drives 4 lamps)
Sockets: Leviton 23351

Having worked at JUNO Lighting for a few years, there are lighting design software packages that can vary quickly do lighting fixture layout to produce the best lighting for your application. Fixture manufacturers provide photometric data for their fixtures that can be used in design software to show where and how well a particular fixture will perform. You can check with light fixture dealers for access to the software. The package I used was based on zonal cavity models. One major benefit aside from having the correct amount of light where you need it is for given fixtures the packages can also do cost analysis.

Tom

gjrepesh said:

I am looking for info on how to figure how many light fixtures I need.
Shop info: 50' wide x 60 ' deep x 14' wall height. Walls and ceiling covered with galvalume metal. I would hang all lights at the 14' level.

Click to expand...

I went through this a few months ago when equipping my new shop which is has a 13ft.8in. ceiling and 1044 sq.ft., i.e. ~1/3 the size of yours but same ceiling height. I based my layout on the illumination level in a laboratory that I knew provided my similar-age eyes good vision.

I have fourteen (14) 4-bulb T-8 fluorescent fixtures uniformly spread around the ceiling and wired with 4 switches so I can turn on 2-bulbs in the fixtures in the "right" side of the garage, all 4 in the "right" side fixtures, all 4 on the "right" and 2 on the "left," etc. in any combination, depending on where I will be working.

T-5 bulbs would seem to be more efficient than the T-8 I decided on, but the ceiling has to be 25 ft. or higher for them to be the right choice. At least, that's what I concluded.

With all the lights on the illumination at working height is 1100 lux, which is that of a surgical operating room. While that sounds like a lot of light, I still supplement it with task lighting at the lathe, mill, etc. With, say, only the lights on the "right" side on the level on that side of the room drops to only ~1000 lux, saving electricity when not needing full brightness throughout the full space.

I used something like this calculator when I put in new lights in my shops a few years ago, there are quite a few free calculators available, with some being quite detailed in what they'll consider.
H.E. Williams Specification Grade Lighting Manufacturer

I was quite surprised at the amount of lighting that was recommended, as it was much higher than just my ignorant "gut feel" would have suggested. However I'm now pleased that I followed recommendations to install the appropriate amount of lighting, even so I still supplement it with task lighting on some machines.

seiner said:

six bulb fixtures can be wired to two switches so you can turn on 2,4 or all 6 bulbs.

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That sounds like a very good feature. I will look at those.

Great responses. As usual, much to digest but worth the effort. Having enough light or the right kind of light is just too important. Thanks.

oldbikerdude37 said:

1,000 watts per 25 SQ FT... Oh that's for indoor gardening.

8 400watt matal halides will light you up good and can hang floros over select machines and benches for additional light.

Im Kind of an expert at lighting and ventilation.

Click to expand...

I had to glance and see you were in Oregon, not here in Colorado.

There are several spaces opening up with MORE than adequate lighting for a shop.

I recently went with 4-foot led replacements for the 4-foot T8 fluorescents. I went with 4000K color temperature (neutral white).

You need to remove the ballast from the fixture, and wire directly to the tombstones (non-shunted).

Electricity costs $.32/kilowatt-hour in my area, so I figure the payback at less than one year, even though I know the price of led lights will keep going down.

The led replacements are brighter, and use about half the electricity. The other advantage is that they should last longer, especially when the lights are frequently turned on and off.


Go to Amazon and search for 4-foot led replacement lights, and non-shunted tombstones, for a better understanding.

gjrepesh said:

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I am looking at 4 tube flourescent fixture t5 HO using the 5000k range bulbs. But will consider other fixtures based on recommendations.

I have read that you should have a fixture for every 250 sq ft, etc. Is there a web site or ? that shows the pattern these fixtures cover, how the height affects coverage, brightness of interior walls, etc. that affects this decision?

Click to expand...

You don't need software for this. It's not that hard.

When I was figuring the light for my shop I spent time in offices and stores counting ceiling tiles and light fixtures and seeing what I thought was "good lighting".

A 4' T-8 bulb gives off about 2900 lumens of light. Check the specs for the exact bulb but it will be around 2900. So that will give you 11600 per fixture.

If you put one fixture for every 250 sq ft that will be about 46 lumens / sq ft. My shop has 120 lumens /sq ft (10' ceiling) and I consider it "well lit". Do the math for some of the other posts and I think 46 comes up a little short.

Ignore watts as that is a measure of how much power is consumed by the device, not how much light it gives off.

A note on those LED bulbs, they only use half as much electricity because they only produce half as much light. Read the specs and do the math, the T-8 and LED bulb both produce about 90 lumens per watt of power used. There is no energy conservation benefit whatsoever from using the LED bulbs.

Steve

What ever you do I would highly recommend a four foot reveal light tube above each machine. With the regular lighting.

If you can mix up the warmth of light you always get better results.

SteveF said:

A note on those LED bulbs, they only use half as much electricity because they only produce half as much light. Read the specs and do the math, the T-8 and LED bulb both produce about 90 lumens per watt of power used. There is no energy conservation benefit whatsoever from using the LED bulbs.

Steve

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Interesting comment. You appear to be correct about the led light output per watt not being much more effective than the fluorescents.

Fluorescent lights light up completely around (360 degrees), and the leds I am using have a light beam of about 140 degrees, directed downward.

Ledwholesalers 20 Watt 4 foot T8 T12 LED Tube Lights with 2835 SMD LED, 45W Fluorescent Tube Replacement, UL Approved, Neutral White, 1923NW - - Amazon.com


Since the reflector above the fluorescent is not 100% efficient, and the led light is more effectively directed downward, it improves the lighting in my shop, while using about 20 watts/bulb, compared to 32 watts/bulb.

On the other hand, a friend converted his T-12's to led, and he said he has more shadows in his "clean room" which has low ceilings.

One of the reasons I switched to led is because of the high failure rate of the T8's when the lights were turned on and off every time I left the room.
I literally would leave the lights on most of the time because it was such a hassle to replace the bulbs all of the time -- that is one of the reasons that I can save on the electric bill -- the lights are only on half as much.



I never really noticed the following comment until now, which discusses the beam angle:

4 of 4 people found the following review helpful
AWESOME
By Steve Dietrich VINE VOICE on September 5, 2014
Color Name: Neutral White
Bought 5 to use in kitchen . Replaced 8 fluorescent tubes . Getting much more light . couple of reasons - these lights have a 140 degree beam width ( light is projected 20 degrees below horizontal ) since 100% of the light is projected across about 40% of the bulb, 250% more light is projected where it is supposed to be going. A great advantage in non reflective fixtures.

I'm looking at florescent and solar mixed. I really don't like florescent when hand machineing do to the strobe effect. This is why I'm going with solar too, LEDs are cheep now days and I can build my own panels myself. I designed machine that's makes a grid the cells just slide into , so very easy to assemble for the DYI guy, like me . the little flashlite from HF is flat 3vdc and very bright Plus very cheep on sale 3bucks . you can't go wrong with this system. power goes out , still have plenty of light. BTW my home driveways is using the same LEDs , just like street lights , very bright.

mikeknell said:

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One of the reasons I switched to led is because of the high failure rate of the T8's when the lights were turned on and off every time I left the room.

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I never really noticed the following comment until now, which discusses the beam angle:

4 of 4 people found the following review helpful
AWESOME
By Steve Dietrich VINE VOICE on September 5, 2014
Color Name: Neutral White
Bought 5 to use in kitchen . Replaced 8 fluorescent tubes . Getting much more light . couple of reasons - these lights have a 140 degree beam width ( light is projected 20 degrees below horizontal ) since 100% of the light is projected across about 40% of the bulb, 250% more light is projected where it is supposed to be going. A great advantage in non reflective fixtures.

Click to expand...

Certainly the LEDs will save many trips up the ladder over the T-8s.

As far as the beam angle aspect, I have to wonder if that 250% is the result of a careful, formal study done with a commercial light meter or whether it's some guy who just spent a bunch of money on LED bulbs "proving" he didn't waste his money.

Not to sound like the crotchety old guy that I actually am, but over the years I've become increasingly convinced that most reviews on Amazon are put there by people paid by the company to give glowing, 5-star reviews.

Steve

Commenting on the idea that LED's have the same efficacy as fluorescent, there are two issues here, what is the total lumens of the lamp and usable lumens from the fixture. Lamp lumens are determined by placing the lamp in spherical photometer that measures the total light output from all directions and angles. A fixture often has reflectors that reflect a portion of the light, but a lot of the light is lost in absorption and by reflecting light back into the lamp. This done by ray tracing. Light that is redirect back into the lamp is lost, as is that from multiple reflection. This is where the photometric data is used. Photometric data is determined by sweeping a mirror across the opening of the fixture and measuring the light levels as a function of angle. Photometric efficiency of the fixtures vary by fixture design. Values of 40 to 70% are not uncommon.
In the case of the LED, there is no need for a reflector so that what the lamp emits is what the fixture produces (assuming no grills, louvers, lens or other light controllers in front of the lamp) and is therefore, effectively near 98% or so.
Beam angle of the fixture determines area over which the light is distributed. A 40 degree beam is considered a flood and is therefore of low intensity (footcandles) over a large area. A 7 degree beam is a spot with high footcandles over small area. Spots would work well over a machine or workbench but not for area lighting.

On the issue of strobing, the electronic ballasts operate in the 20 to 50 Khz range and are essentially strobe free. The ones that cause the problem are to core and coil magnetic ballasts.

As far as the calculations are concerned, yes, light fixtures can be strung and can be made to produce enough light. But is this the optimum layout and choice of fixtures and lamps. There are two costs involved, the initial cost and the running cost. A calculated design will optimize both costs. Since most lighting companies offer the use of the software why not use it.

Tom