Forget Shoplights!! LED strips inside of the Ceiling Joists

gnarlyleech · Jan 31, 2016

I was trying to figure out how many shop lights I would need to get the required about of lumens in my new workshop. According to a calculation I found somewhere, I would need at least 87,000 lumens for my 512 sq ft shed.
T-8 bulbs are available with 3000 lumens per bulb. That would require me to get at least 16 fixtures with 2ea 48in bulbs per fixture. The cheapest fixtures alone would cost $320 for 16 of them. Add the bulbs to that. Then I thought about where I would put them. I am already a little less than 8 feet of head room.

I was really interested in the LED versions of the shop lights. These come in right at $35. Way too much cash for me to dish out. I could buy tools with that money.

So I found these lights on amazon. LED Lights LEDMO 5630
They come in 16ft rolls for 10 bucks. The plus side? I would only need to install 13 16ft sections to get my 87,000 lumens. LEDS run cooler and use less juice. If a section goes out, it's only $10 for a new set.

Next is how to power them. They need 12volts to run.
You can purchase a power supply to feed power to them. Its the same size as a laptop charger. But at $10 a pop for a 60w charger, I new I could do better than that. It comes out to 16 cents per watt. Also a few shaky amazon reviews of them burning up cured me of that idea.

I work around a lot of automation and PLC controls so I knew there were cheaper power supplies to be had. Meanwell to the rescue. They make a power supply at every level you can imagine. They also make power supplies just for LEDs. Although, they are more expensive, and to me, 12volts is 12volts and the LEDs don't know any different either.

I went with these at around 12 cents per watt. MeanWell LRS-350-12
It has its own cooling fan and power management protection that is exactly what I was wanting. Pulling around 7 amp at 120volts max, I could put 2 per 20 amp breaker. It may never pull 7 amps but I error of the side of caution. I purchased 4 units which will give me enough space to power 16 light strips 16ft long.

Enough introduction. Here are the pictures.

Mounting the power supplies. Probably just temporary until I come up with a better mounting solution.
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Next idea I had, how will I mount the LED strips to the ceiling. If I put them on the bottom of the ceiling joists, I will hit them with something by accident, a board of plywood. So I needed to find a way to protect them. Aluminum c channel came to mind. But it would take $2000 worth of it. So next idea. What if I routed a channel in the ceiling joists for them to slide into. VOILA!!!!
I walked around Lowes router bit section and saw the 1/2 dovetail bit. It would have worked great. But I went with this instead. Keyhole bit
I just needed to make a jig with some angle iron so my router would pass down the center of the joists.
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Side view
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Here is the final result. It was a tight fit. I would like to try the dove tail bit to see how it would be.
I didn't install a light in every joists, but I think I will go back and do that to make it even brighter.

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Pulling the lights into the groove
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I don't have any install in the back corner yet so it is still dark back there.

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After I install the interior walls and paint everything white, it will be much brighter too.

So what do yall think? Questions? Concerns? Let me know how I can improve upon this.
I have more information on my setup if anyone wants it. I can go further into detail on how I wired up the power supplies to the light switches and what size wire I used for the LEDS.

_

Gasgt1 · Jan 31, 2016

That is cool :thumbup:

Fueler · Jan 31, 2016

This is one of those why didn't I think of that things. Very creative. Well done.
So much so that I have a place to do just this.

Could you show a little more and explain how the strips are cut and terminated to the power boxes?

Showkey · Jan 31, 2016

Nice job........

Curious on the amount of light reaching the miter box table or bench top. Using a smart phone app could you measure the LUX at different places and levels ?

gnarlyleech · Jan 31, 2016

Showkey said:
Nice job........

Curious on the amount of light reaching the miter box table or bench top. Using a smart phone app could you measure the LUX at different places and levels ?

I sure can. that kind of research is right up my alley. It will take me a week or so to assemble that data, but I've got this in my head now and I kinda want to know also. I didn't know that there was such an App. I'll add it to my calendar and let you know what my results are. It will probably be in a week and a half.

jives · Jan 31, 2016

Okay, what is with the pink studs? Are those anti-mold or something?

brownsmustang · Jan 31, 2016

It looks freaking awesome! I may have to sell my fluorescent fixtures!

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Richard Cranium · Jan 31, 2016

what is with the purple/pink lumber?

cybrdyke · Jan 31, 2016

the output current of the meanwell is 29 amps? Can the LED strips handle that?
CD

Ainsley · Jan 31, 2016

Looks great! I've used similar LED Strips in my car and my boat, love working with that stuff!
What Colour temperature did you go with?

brownsmustang · Jan 31, 2016

Richard Cranium said:
what is with the purple/pink lumber?

It's usually mold/insect resistant.

Sent from my SM-N910V using Tapatalk

APEowner · Jan 31, 2016

Cool. I'm looking at those same LED strips for lighting in the race trailer. They look great in the pics. Does it feel like the light is evenly distributed?

gnarlyleech · Jan 31, 2016

Fueler said:
This is one of those why didn't I think of that things. Very creative. Well done.
So much so that I have a place to do just this.

Could you show a little more and explain how the strips are cut and terminated to the power boxes?

Yes I can.
so each light comes with a standard 2.1mm x 5.5mm female power plug. so I just bought these to connect my wire to that connector.

2.1mm x 5.5mm Male connector Link

The wires just get pinched in the back of the connector.
You could also Solder the + and - onto the LED strip. It's very easy to do. These LED strip and really easy to work with. You can cut them to the length you need. Very cool for mounting them around bends like under cabinets.

Another important aspect of the LED's lights. They run off of 12v. Because of the low voltage, the distance of the LED from the power supply will determine what gauge wire you will need to use. If you use too small of a wire, following OHM's Law, the lights will pull too many amps and the wire and lights will run hotter. I used a voltage drop calculator so I could use the smallest wire possible. My furthest run is 40 ft, for which I used 10/2 cable tray wire. As I got closer to the power supplies, I was able to drop the wire size down. The smallest I used was 14/2. Each run of wire is powering 2ea 75 watt strips for 150 watts total. 150watts at 12vdc is 12.5 amps. Using this Voltage drop calculator you can see what I mean.

At 40 feet, 12.5amp, 12 volts DC, the voltage at the end of the wire will be 11 volts. the LED's need 12. This is where the power supply saves the day. There is a POT screw on the power supply where you can increase the output voltage. Lets check it on our calculator. Increasing the voltage to 13 volts gives us our 12 volts at the end. Problem solved.
I did this for every run and the lights aren't dim and they don't run hot. I can hold the LED lights in my hands after running all day and it is barely luke warm.

Another good tutorial on LED strips.

To install light switches, I just wires the switches to the 120ac going to the power supplies, just like a light bulb. real simple.

If my calculations aren't correct, let me know so I can learn something.

ForceFed70 · Jan 31, 2016

Very cool!

Think spaying a coat of white paint in there would have helped reflect more light?

It should be noted that you have lowered your beam strength by doing this install.

brownsmustang · Jan 31, 2016

ForceFed70 said:
Very cool!

Think spaying a coat of white paint in there would have helped reflect more light?

It should be noted that you have lowered your beam strength by doing this install.

Very minimally imo.

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gnarlyleech · Jan 31, 2016

jives said:
Okay, what is with the pink studs? Are those anti-mold or something?

lol. I'm guessing that those pink studs aren't distributed at every lumber yard in america like I thought. It is suppose to protect from termites or something like that.

gnarlyleech · Jan 31, 2016

cybrdyke said:
the output current of the meanwell is 29 amps? Can the LED strips handle that?
CD

I connected 4 light strands 16 ft long to each power supply . each 16ft strand is 75 watts. times 4 is 300watts or 25 amps. The power supply is rated for 350 watts. LED suppliers recommend a 20% cushion. I am at about 15% but now that I think about it, I had to trim a little off of each light strand so I may be closer to the 20% mark.

checkthisout · Jan 31, 2016

LOL, I got the same 12V "transformers" and strip lights off Amazon about 4 years ago for lighting in my chicken coop.

The transformer still work good but the LED strip have bulbs that go bad for whatever reason. You can replace groups of 3 of them (as I am sure you know) without much hassle.

That looks good. I like it. Very creative and good execution.

gnarlyleech · Jan 31, 2016

ForceFed70 said:
Very cool!

Think spaying a coat of white paint in there would have helped reflect more light?

It should be noted that you have lowered your beam strength by doing this install.

First part
My idea was to buy some cheap white mini blinds and cut the string and install the blades as light diffusers. I don't feel like I need them after seeing the lights though. TheLED Light isn't too sharp, just don't look up at them. Those LEDs are bright! There are companies that make acrylic diffuser material but it is expensive. If you could find an old office like setup you could cut it into small strips and install it over the joists. I may do that if I ever find one at the junk yard.

Second part
I was waiting for the beam strength comment to pop up soon. I agree, I have lowered the beam strength. I cut into the joists a 1/2" at least making a channel .375" at its widest point. For a 1.5" wide board, you are only loosing .375" in the center which is 25% the width of the board. I will assume that the same building code that applies for notching load bearing wall studs applies for the joists which states "Notches in bearing wall studs may not exceed 25 percent of the stud's width".
Of course, mechanically speaking, the joist is weaker because I removed some material. But it isn't significant enough to cause alarm or damage. But I don't think this would be a problem for anyone wanting to do this, unless the joist are rotted and hanging by a thread In a house the joist would have been 2x10 or 2x12 depending on the span, but in my workshop 2x8 was just fine for me. It would be different if I removed a whole inch from the bottom of the joist to make them 2x7s.

Also, it would be better to route the grooves on a router table as opposed to holding a router up above your head. My arms were really tired after all that.

gnarlyleech · Jan 31, 2016

Ainsley said:
Looks great! I've used similar LED Strips in my car and my boat, love working with that stuff!
What Colour temperature did you go with?

These put out around 6000-6500K according to the manufacturer. I haven't measured it but it feels right. I use the same thing in my house. Its just right for a workshop where you need bright light. I dislike that temp for a house light though, its too sharp. I'm just so invested in my home lights that I can't mix and match. I have so many that it would cost a fortune to switch. lol

gnarlyleech · Jan 31, 2016

checkthisout said:
LOL, I got the same 12V "transformers" and strip lights off Amazon about 4 years ago for lighting in my chicken coop.

The transformer still work good but the LED strip have bulbs that go bad for whatever reason. You can replace groups of 3 of them (as I am sure you know) without much hassle.

That looks good. I like it. Very creative and good execution.

They are awesome. I actually first though about them to install under my cabinets in the kitchen. While trying to figure out how to install them, I came up with this idea. How are the chickens? how big of a coup did you have?

UpNorther · Feb 1, 2016

Great idea of putting them in the trusses! They turned out really nice and looks like they give good even light.

APEowner said:
Cool. I'm looking at those same LED strips for lighting in the race trailer. They look great in the pics. Does it feel like the light is evenly distributed?

I have them inside my 18' enclosed. They work great. A 15' strip uses 2a, so a battery lasts a long time. I ended up putting 2 zones in so I could dim it down inside. I used 4', 3', 3', 4' strips on every other ceiling rib.

Aerogt01 · Feb 1, 2016

gnarlyleech said:
Second part
I was waiting for the beam strength comment to pop up soon. I agree, I have lowered the beam strength. I cut into the joists a 1/2" at least making a channel .375" at its widest point. For a 1.5" wide board, you are only loosing .375" in the center which is 25% the width of the board. I will assume that the same building code that applies for notching load bearing wall studs applies for the joists which states "Notches in bearing wall studs may not exceed 25 percent of the stud's width".
Of course, mechanically speaking, the joist is weaker because I removed some material. But it isn't significant enough to cause alarm or damage. But I don't think this would be a problem for anyone wanting to do this, unless the joist are rotted and hanging by a thread In a house the joist would have been 2x10 or 2x12 depending on the span, but in my workshop 2x8 was just fine for me. It would be different if I removed a whole inch from the bottom of the joist to make them 2x7s.

Also, it would be better to route the grooves on a router table as opposed to holding a router up above your head. My arms were really tired after all that.

Edit: By my guesstimate:
You have not significantly reduced the beam's moment of inertia and thus strength, but every case is different and will depend on the rated load vs actual applied load.

The important thing is you did not notch it cross-ways, cutting fibers that would otherwise be continuous.

Beemer533 · Feb 1, 2016

Very cool! I did the strip lights under my cabinets in the garage, works very well.

Nice job..

cybrdyke said:
the output current of the meanwell is 29 amps? Can the LED strips handle that?
CD

The power supply doesn't "push" current out like that.

Whatever load (in this case, the lights) you connect to a power supply will only pull what it needs.
You could use a 1000a supply with a single led and it would be fine, as long as the voltage is correct ..

This post edited by the NSA

theoldwizard1 · Feb 1, 2016

Very cool !

Nervous nellies will tell you that you have weakened your joists, but it would be minimal.

Chevy-SS · Feb 1, 2016

gnarlyleech said:
Also, it would be better to route the grooves on a router table as opposed to holding a router up above your head. My arms were really tired after all that.

Alternatively, just use a 1x2 as light-holder instead of routing into the joists. Then mount the lights into the 1x2 and then mount the 1x2 onto the joist.

Very neat idea!! :beer:

gnarlyleech · Feb 1, 2016

Chevy-SS said:
Alternatively, just use a 1x2 as light-holder instead of routing into the joists. Then mount the lights into the 1x2 and then mount the 1x2 onto the joist.

Very neat idea!!

Excellent idea.

I saw another cool idea where a guy mounted the lights in some roof flashing L-channel is hung it from the ceiling on chains.

aka Larry · Feb 1, 2016

First, I love the idea.

Second the jig for the groove is awesome.

gnarlyleech said:
You could also Solder the + and - onto the LED strip. It's very easy to do. These LED strip and really easy to work with. You can cut them to the length you need. Very cool for mounting them around bends like under cabinets.

I have these under my cabinets and the connectors they sell to connect one strip to another, ****. I have not found soldering them to be easy either, but to be honest I **** at soldering.

Dick in Wisconsin · Feb 1, 2016

That is really, really slick. Especially for any situation where the ceiling will be left open; basements included.

The more I read about DIY LED installs, the more I am learning.

Question to the OP. LED's put out a modest amount of heat (emphasis on "modest"). Is the heat material enough to cause a problem? Weakening the structural members you've installed them in? Creating a possible fire hazard? After leaving the lights on for a long period of time, how "hot" do the LEDs get and how "hot" is the wood? What do the building codes say about this kind of installation?

gnarlyleech · Feb 1, 2016

**** in Wisconsin said:
That is really, really slick. Especially for any situation where the ceiling will be left open; basements included.

The more I read about DIY LED installs, the more I am learning.

Question to the OP. LED's put out a modest amount of heat (emphasis on "modest"). Is the heat material enough to cause a problem? Weakening the structural members you've installed them in? Creating a possible fire hazard? After leaving the lights on for a long period of time, how "hot" do the LEDs get and how "hot" is the wood? What do the building codes say about this kind of installation?

About the Heat
The problem I have seen with LEDs getting hot is using a supply voltage that is too low. This happens a lot in automotive applications. If the LED is rated for 12 volts and is only getting 9 volts, it compensates for that low voltage by drawing more amps. If a car electrical system can supply 14.5 volts to the LED this isnt a problem. But tying in an LED light strip to a 18 awg light circuit that is already at max capacity with the other lights tied in that circuit, you get HOT LEDS. Adding too many LED's can do the same thing.
This can be remedied by calculating for voltage drops and adjusting accordingly and always try to leave a 20% cushion. If you have 100 watts of lights, setup your system to be rated for 120 watts. Even up to the max rating would be better that going over it, not that you should.

My LED strip temp
After running all day, I can hold them in my hand and they seem to not give off any heat.

Just use Ohms law and the 20% rule and you will be fine.

-

LXCam · Feb 1, 2016

OP, that's a killer idea. The shop looks well lit with no shadowing. I just might have to do the same thing in my next shop. Keep up the great work. :beer:

cybrdyke said:
the output current of the meanwell is 29 amps? Can the LED strips handle that?
CD

It doesn't work like that. The power supply can provide that much, it's doesn't force it's max current through. It only supplies what the load draws which as the OP said still has 15% head room.

Crusarius · Feb 1, 2016

Computer power supplies will also work for power. they have 3 volt 5 volt and 12 volt wires. And some of them are over 30 amps.

Beemer533 · Feb 1, 2016

Crusarius said:
Computer power supplies will also work for power. they have 3 volt 5 volt and 12 volt wires. And some of them are over 30 amps.

This is what I do for my landscaping lighting (all 12v LED). I modified an old 800 watt ATX supply and control it with a photo cell. Cheap and powerful..

This post edited by the NSA

Dick in Wisconsin · Feb 1, 2016

There seems to be a few more things to take into account when doing lots of LEDs vs some kind of incandescent or halogen solution. Seems like LEDs are more sensitive to somethings we never worry about with the incandescent or halogen lights.

Have I arrived at a valid conclusion?

AirJunky · Feb 1, 2016

**** in Wisconsin said:
There seems to be a few more things to take into account when doing lots of LEDs vs some kind of incandescent or halogen solution. Seems like LEDs are more sensitive to somethings we never worry about with the incandescent or halogen lights.

Have I arrived at a valid conclusion?

Like what? All my garage lights are LED bulbs & one 4' tube. I haven't had any problems.

gnarlyleech said:
I saw another cool idea where a guy mounted the lights in some roof flashing L-channel is hung it from the ceiling on chains.

haha, so why does the little dog have to sit on the big dog?? :lol_hitti

gnarlyleech · Feb 1, 2016

**** in Wisconsin said:
There seems to be a few more things to take into account when doing lots of LEDs vs some kind of incandescent or halogen solution. Seems like LEDs are more sensitive to somethings we never worry about with the incandescent or halogen lights.

Have I arrived at a valid conclusion?

I think you have. It's a switch from 120 volt AC to 12 volts DC. Its the same electricity, just in a different form. A little youtube and google research goes a long way. I would only suggest installing something like this if you fully understand how DC voltage works and how the LEDs work. When you truly understand the system, you can change it and adapt it to what you want.
I spent the last 2 months learning about LEDs and what would be best for my situation. I now have that knowledge and it can't be taken away. The world needs more Renaissance men.

gnarlyleech · Feb 1, 2016

AirJunky said:
Like what? All my garage lights are LED bulbs & one 4' tube. I haven't had any problems.

I am guessing that you are talking about the LED bulb replacements for T-8 fluorescent fixtures? There are 2 types that I know of:
1. one you have to remove the ballast from the fixture and wire 120v ac directly to the bulb. This kind has a DC volt power supply built into the bulbs.
2. The other kind can be used with or without removing the ballast. I think they are called Retrofit Bulbs.

This is just an expensive option to what I decided to do. I guess if you already had t-8 fixures, it would be easier to just replace the bulbs with the retrofit kind.

404 · Feb 1, 2016

gnarlyleech said:
About the Heat
The problem I have seen with LEDs getting hot is using a supply voltage that is too low. This happens a lot in automotive applications. If the LED is rated for 12 volts and is only getting 9 volts, it compensates for that low voltage by drawing more amps. If a car electrical system can supply 14.5 volts to the LED this isnt a problem. But tying in an LED light strip to a 18 awg light circuit that is already at max capacity with the other lights tied in that circuit, you get HOT LEDS. Adding too many LED's can do the same thing.
This can be remedied by calculating for voltage drops and adjusting accordingly and always try to leave a 20% cushion. If you have 100 watts of lights, setup your system to be rated for 120 watts. Even up to the max rating would be better that going over it, not that you should.

My LED strip temp
After running all day, I can hold them in my hand and they seem to not give off any heat.

Just use Ohms law and the 20% rule and you will be fine.

-

The low voltage overheating problem exists in electrical motors. It does not exist in a circuit that has just leds and some resistors.

PCMusicGuy · Feb 1, 2016

Looks great! Wish I could do it but it's not practical for a garage or shop with a ceiling that uses the joist for attachment of sheetrock, etc. Also, did I understand correctly that you are using two 20 amp breakers just for your lights?

gnarlyleech · Feb 1, 2016

PCMusicGuy said:
Looks great! Wish I could do it but it's not practical for a garage or shop with a ceiling that uses the joist for attachment of sheetrock, etc. Also, did I understand correctly that you are using two 20 amp breakers just for your lights?

Yes I am. The max draw of each power supply was almost 7 amps. times 2 power supplies is 14 amps and a 20 amp breaker leaves my 20% cushion. I know that most outlets are pushed to the 20 amp limits most of the time, I just wanted to build according to code.

Forget Shoplights!! LED strips inside of the Ceiling Joists

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