Crawl space lighting

Ira

Active Member
Home has a crawlspace that is about 100' x 40'. Bottom of floor joists are 3' above concrete crawlspace floor (foundation). Crawl space is "closed", i.e., it doesn't have any vents to the outside, the exterior walls of it are insulated, and it has a dedicated dehumidifier. In other words, it is part of the building envelope. All floor joists go in the same direction. There are quite a few pony walls supporting the floor joists, that kind of make "paths" to get to different areas. Think of the pony walls as short, "open", load bearing walls, i.e., they are 2x6's, one treated bottom plate, two top plates, and "studs" are 16" OC.

Trying to decide how to light the crawl space. Rather than putting light fixtures in various places in the crawl space, I am wondering if LED strip lights would be a good solution. I could attach them to the sides of the pony wall top plates so they wouldn't be in the way and less likely to be damaged. At about $2/foot, I don't think it would be terribly expensive. I don't have to deal with line voltages, except to the transformer(s).

One more thing... the pony walls pretty much all run in the same direction, perpendicular to the floor joists. Distance between pony walls vary between 5' and 10'. I need the strips (or whatever I end up using) to provide general lighting (and it doesn't have to be "daylight bright) to get around the crawl space. Additional lighting can be used when working on something in the crawl space, e.g., the dehumidifier.

What I don't know (I've never used them) is how many feet I would need, how much coverage/brightness a strip of a given length, e.g., a 5' strip, would provide, etc. Most of the youtube videros show them as being dim accent lighting under a cabinet, around the back of a TV, etc. I can buy some to experiment with, but I'm curious if any of you have tried to light up a large area with LED strips. Comments?
 
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electron

Administrator
Staff member
Most affordable LED strip lighting is just accent lighting as you mentioned, but in a dark space, it could still be pretty effective. Take a look at the 'The Hook Up' YouTube channel, which has some really good comparison videos about LED strips, diffusers, and his permanent christmas lighting setup.


The other option I'd consider are the popular LED workshop lights, which can be daisy chained, and have a single 2-prong plug. Should be easy to automate with an appliance module:

 
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Ira

Active Member
The LED workshop lights may be a good way to go if I can find some that offer a little more flexibility in the layout. I'm surprised at how bright some of them are, e.g., 5000lm for a four foot light. It will take some trial and error to figure out how many lights, where to place them, etc., but a few strategically placed outlets with smart switches in them should be a good start.

Thanks,
Ira
 

LarrylLix

Senior Member
I would consider continuous LED strip lighting with an IP67 silicone jacket. The 5m strips run off a 12v dc power supply and are completely encased in a silicone tube for about $12-15 per 5m length. You should be able to run 6-10 strips off a single 12v 5A power supply easily. However they voltage drop on sequential strips can be severe if you concatenate more than two 5m lengths from one end. Some form of 12v centre bus feed come to mind there.

The biggest problem I see are mounting them. Don't trust the self-adhesive ones they sell as a few hours after they are turned on the adhesive gets soft and they fall off. There are metal tracks they snap into that looks convenient, but that may double your costs.

Another factor I would consider is that you may be laying on a creeper or "skateboard" of some sort to pull yourself a round in the crawl space and you may be staring continuously at the overhead lighting while inside the space. IOW: I would also avoid colour temps over about 3000K.
 

Ira

Active Member
Reporting back...

I bought a roll of "JOYLIT 24V COB LED Strip Lights 16.4ft 4000K Natural White 439lm/ft Super Bright CRI 95+, UL Premium No Dark Spots 480LEDs/M 7200lm 90W Indoor Pro Tape Light", a "LED Strip Channel with Diffusers, Starland Led 6-Pack 1Meter/3.3ft LED Aluminum Profile Track Housing V-Shaped with Cover and Complete Mounting Accessories for LED Strip Light". I cut the strip to the length of the track, put it all together, and switched it on in a 12'x15' dark room. It lit up the entire room, even when I held it 3' above the ground. And that's with the "corner track". The COB LED strip eliminates all of the runway effect. I think an 18" strip would have been enough for the area.

The LED strip cost about $40. A one meter track costs about $2.50 when bought in quantities of 20. That includes the aluminum trick, diffuser, end caps, mounting brackets, and screws. The LED strips are only IP20. I figured that since the crawlspace is completely closed and conditioned, and the strips are in tracks with covers, IP20 would be okay. There are probably cheaper options, but this setup was easy to get quickly.

I'm guessing that 10 lumens per sqft is bright enough for what I need, so the crawlspace needs a total of 35,000 lumens. At 439lm/ft, that's about 80 linear feet, or about five rolls. I will need about 500 watts of power, which won't be cheap. I need to experiment some more, but I'm hoping that about 50 "lights" (each 18" long) distributed around the crawlspace will be good.

I plan on wiring these all in parallel instead of daisy chaining them. It will take more wire, but I won't see the voltage drop. Also, by wiring everything in parallel, it will be easier to add more strips if necessary to light up dark spots (assuming the transformer isn't maxed out).
 
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