Lighting layout

[Buzz Saw]

I'm looking to install shop lights in my new pole building. It's basically a 40x60 with 14' walls. I'm planning on using hand-me-down light fixtures. The fixtures are four lamp 4' T8 but I'm thinking of only using 2 lamps per fixture. Is only 2 lamps enough output? I think I have around 40-50 fixtures. I also have enough lamps to fill the fixtures at least once.

What should my layout be?
How apart on center?
Should the fixtures be installed in one continous line? Or gaps between fixtures?

Any help would be much appreciated. Thank you.

 

[jebatty]

Google "lighting layout" and you will find a variety of sites/tools to help you plan your lighting. The major question is how much light you need where? My answer to this question in my 32 x 48 x 12 shop was 22 - twin 48" T8 fixtures with electronic ballasts. That was in Spring 2010 when the lighting went in.

If I had to do it now, I would go with 48" LED fixtures, about 1/2 the power, brighter, and not much more expensive if purchased new. After 5 years, light output from the T8's has degraded substantially. I have replaced nearly 1/2 the T8's with direct replacement 48" LED tubes. The LED's even are brighter than brand new T8's.

If your used T8 fixtures have magnetic ballasts, forget it.

 

[semipro]

I'd suggest you think about it like kitchen lighting. You have area lighting for general activities like walking around safely and then task-specific lighting where certain areas are more highly illuminated. You may also want to create multiple staggered circuits where say every other light is on one circuit for the area lighting.
Also consider the value of a reflectors whether the structure or on the fixture itself. If you're using T-8 fixtures that don't focus the light downward then much light will be lost upwards. A simple coat of white paint on the ceiling or bottom-side of the roof can make a big difference in overall illuminance and lighting efficiency.

 

[seige101]

You say 4' t8 4 lamp fixtures are these strip lights or 2'x4' trooffers that would sit in a drop ceiling grid? You should just put the 4 lamps in instead of 2 for 3reasons 1, you will still be using some extra power in the ballast with the lamps removed 2, the ballast likes to see it's rated load or it can/will fail prematurely 3, it probably won't be enough light mounted at 16' high.

As others have said look into LED it may cost more upfront but the benefits and savings will be better.

 

[Buzz Saw]

You say 4' t8 4 lamp fixtures are these strip lights or 2'x4' trooffers that would sit in a drop ceiling grid? You should just put the 4 lamps in instead of 2 for 3reasons 1, you will still be using some extra power in the ballast with the lamps removed 2, the ballast likes to see it's rated load or it can/will fail prematurely 3, it probably won't be enough light mounted at 16' high.

As others have said look into LED it may cost more upfront but the benefits and savings will be better.

They are "trooffers", based on your description. The fixtures and lamps are FREE so it's hard to turn down. I'm all for LED'S, but at the time it's not in the cards. Other things need purchased first.

 

[Buzz Saw]

Google "lighting layout" and you will find a variety of sites/tools to help you plan your lighting. The major question is how much light you need where? My answer to this question in my 32 x 48 x 12 shop was 22 - twin 48" T8 fixtures with electronic ballasts. That was in Spring 2010 when the lighting went in.

If I had to do it now, I would go with 48" LED fixtures, about 1/2 the power, brighter, and not much more expensive if purchased new. After 5 years, light output from the T8's has degraded substantially. I have replaced nearly 1/2 the T8's with direct replacement 48" LED tubes. The LED's even are brighter than brand new T8's.

If your used T8 fixtures have magnetic ballasts, forget it.

I've done this but I'm not familiar with the nomenclature of lighting. Do I look at lumens or watts? How do I know how many lumens come from a T8 bulb. It's all foreign to me.

 

[seige101]

What are you looking for light, general lighting? Task Lighting? What are you doing in your building?

For general lighting i would space the fixtures as per my crude drawing. Assume i drew all the fixtures in .If most of the general area is just storage delete 1 row and 1 column of lights column and adjust spacing accordingly. For work benches or specific task lighting, over machines etc add more lights. For a work bench i like to put the lights end to end the length of the bench centered on the front edge of the work bench.

 

[Buzz Saw]

General lighting at the moment. I want to get this right BEFORE I do all my insulating and sheeting, etc.

Today at Sam's Club I picked up an LED light fixture to do a comparison vs the T8 fixture. From the little I've tested I think I want to do LED if I can sell all my T8 fixtures at $10-$20 each I'll go for the LED fixtures from Sam's Club. Only downside to the Sam's LED'S is that the install requires them to hang from chains. No "hard mount" from what I've seen.

(broken link removed)

 

[Buzz Saw]

What are you looking for light, general lighting? Task Lighting? What are you doing in your building?

For general lighting i would space the fixtures as per my crude drawing. Assume i drew all the fixtures in .If most of the general area is just storage delete 1 row and 1 column of lights column and adjust spacing accordingly. For work benches or specific task lighting, over machines etc add more lights. For a work bench i like to put the lights end to end the length of the bench centered on the front edge of the work bench.

Seige, On your diagram you have 6' between fixtures. That would be 8' on center correct? That will work out great ad my trusses are 4' on center.

I read on your profile you're an electrician, mind if I pick your brain. I'm fairly confident in my wiring abilities, but I'm sure I am always super conservative on my loads per circuit.

Question 2. Would you put that many lights in one or two 15amp circuits? I also plan on breaking the lights into 3 separate switches.

Question 3.you think it would be ok put the garage door openers on the circuit with only switch of lights?

Thanks.

 

[seige101]

8' on center sounds right, double check my math only firing on 1 cup of coffee so far today.

Yep, an electrician for 15+ years this year wow time flies. Longer if you count wiring my tree forts when i was a kid!

Pop open one of the covers on the lights i am pretty sure a 4 lamp t-8 ballast is about 1 amp at 120 volts. You could safely put 12 fixtures on 1 circuit (never load up a circuit to more than 80% of it's rated capacity)

Add up total fixtures you are installing and divide by 12 (assuming each fixture is 1 amp) this is the # of circuits you need for lighting.

I would put the garage door openers on their own circuit.

If you have any other questions ask away!

 

[Buzz Saw]

Well I ended up going with the LEDs from Sam's Club. 24 fixtures at the moment,.about 4 more when I locate my workbenches. I ran the numbers for operating expenses and the LEDs will pay for themselves in a fee years. And man they are BRIGHT, It's awesome.

Have a Happy bright day.

 

[seige101]

I think you will be happy with them! Show us a pic or 2!

 

[Buzz Saw]

Here's some pics

Some of the lights in the box


Recepticles in the ceiling


Close up of a light installed. The lights are sold as a hanging "only" unit. Well I just drilled two holes in the fixtures and screwed them to the ceiling. Don't worry in the attic I installed a 2x4 between each truss to screw the light into.

 

[Buzz Saw]

Let there be light.


This is the first half done. One switch one circuit. This circuit is also going to power the lights in the bathroom and "workout" room. There is also a few more fixtures to install over workbenches, that have yet to be located. Pushing/ pulling the scaffolding through stone is not fun.


And more light. This is the second half. One circuit, one switch. This circuit is going also going to power the out door lights.

 

[Buzz Saw]

I ended up doing the fixtures 4' and about 9' between rows. The first row is 9' from the wall and the last row is about 3' from the other wall. I did this to create room for a row of lights for the work benches on the "first" wall. I hope that made sense, if not let me know and I can post my sketch(after I find it or make a new one).

 

[jebatty]

Looks like you did a good job. My shop layout is similar to yours. I used a split 240V circuit so 1/2 the fixtures draw from one line and the other half from the other line, balance the loads. Also, the wall light switch turns "on" only the fixtures in the front half of my 32 x 48 shop, that's where the work benches and power tools are and where the light is really needed. The fixtures in the back half are all on string pull switches on each fixture so I can turn on only when actually needed. Most of the fixtures in the front half now are fitted with LED's. As for you, very bright and about 1/2 the watts of the prior T-8's.

 

[Buzz Saw]

Looks like you did a good job. My shop layout is similar to yours. I used a split 240V circuit so 1/2 the fixtures draw from one line and the other half from the other line, balance the loads. Also, the wall light switch turns "on" only the fixtures in the front half of my 32 x 48 shop, that's where the work benches and power tools are and where the light is really needed. The fixtures in the back half are all on string pull switches on each fixture so I can turn on only when actually needed. Most of the fixtures in the front half now are fitted with LED's. As for you, very bright and about 1/2 the watts of the prior T-8's.

I set my breakers up like a 240 two pull breaker. The two single pulls breakers are stacked just like a two pull breaker, balancing the loads on line 1 & line 2.

I always try to balance the panel as evenly as possible, but sometimes it just doesn't work out that way.