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Based on typical recommendation, my garage workshop should have 50k lumens of illumination. It seems challenging to accomplish this with LEDs - I would either need a lot of regular LEDs, or a good amount of very expensive high-intensity ones.

However, it looks like HID bulbs in the 250-400W range are much cheaper and have much better lumen output, and some are dimmable. Specifically, these are usually metal halide, sodium vapor and similar designs. Usually these are advertised as for outdoor or large warehouse/shop use. However, could I not install them in my garage?

Would it be difficult to manage the heat produced by such lamps? Would I have to suspend the lamp with some clearance from the ceiling? Is the mogul socket more complicated to wire than a regular one?

Details of the estimate:

  • For a workshop, the recommended light is 80-100 foot candles
  • My workshop is about 500 sqft
  • Based on the formula, lumen = 500 sqft * 100 foot candles = 50k
gomennathan
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    Note that even HPS (the less yellow-y sodium vapor) has absolutely awful CRI, and MH has a lot of control restrictions (can't hot restrike, for instance), so you'll have to keep that in mind when making this decision – ThreePhaseEel Sep 19 '23 at 04:11
  • @ThreePhaseEel For sodium, yes. That's the obvious compromise. For those who don't know, it's the nasty yellow lights used for some street lights. It is of course cheap and wildly available. – gomennathan Sep 19 '23 at 04:37
  • For the control issue, yes, but that doesn't seem like a big problem for a workshop. Usually, you would turn on the workshop light, go work for a bit (1+ hours), finish up, turn it off and leave. It's possible to install secondary (lower lumen) lighting on a separate switch for times when you need quickly pop in. – gomennathan Sep 19 '23 at 04:39
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    HID needs specific fixtures - you can't just wire up a mogul socket to line power, it needs to also have a ballast. You really need to get out of the idea of light bulbs and in to the range of integrated fixtures for this. See my answer for more details. – KMJ Sep 19 '23 at 05:20
  • That's a terrible idea, those lights flicker, buzz, and get hot, all while looking like crap. You're asking for a headache using such a source as a worklight. they are good for when you just need to see and nothing else (ala parking lots), not when you have to linger. – dandavis Sep 19 '23 at 07:38
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    Honestly, you'd be better off with some standard E26 style sockets and UFO LEDs. Those will put out plenty of lumens. – Huesmann Sep 19 '23 at 11:48
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    That sounds like an immense amount of light. What area? What lumens/m^2? What calculations did you base that on AND have you experimented with LED lighting over a smaller area to see how they fare in practice? Having movable spot lighting for special tasks may be a valid option. This can be easily moved and positioned. And, probably, not needed for most tasks. – Russell McMahon Sep 19 '23 at 13:35
  • 4 pieces 150W UFO garage lights = 60k lumens for $70, or $75 if you don't have 4 ye olde light sockets. Add a few shop strip lights for important areas that don't get good cover, eg underneath the open overhead door. – jay613 Sep 19 '23 at 14:08
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    What "typical recommendation" are you talking about? I mean, I love a brightly lit garage, it'll be nice, but this is not how most garages are lit and I've never seen it "recommended" anywhere. I'm just curious. – jay613 Sep 19 '23 at 14:22
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    50k lumens seems excessive. A double garage (roughly 400 sqft) lit to an even 50fc all over (which is a nice bright level for detailed work) only requires about 20k lumens. How large is your garage? Do you really need that same light level over every square foot of it, or would 'task lighting' of particular zones be more effective? – brhans Sep 19 '23 at 17:35
  • @jay613 I've added the source and calculations for where I get 50k. Note that the space is used mainly for working on projects (eg. woodworking) and occasionally repairing cars. It is not used to store vehicles. That's why I said workshop. – gomennathan Sep 19 '23 at 17:54
  • Are you saying that I could get 4 UFO lights, each 15k lum, at $18 a piece? Where do you get a deal like that??? Or are you saying get them at $70 for $280 total? – gomennathan Sep 19 '23 at 20:44
  • T8 LED bulbs shouldn't be outrageously expensive (ahem: https://www.amazon.com/dp/B0CCW6TJRL - GE, which means they're hopefully not Chinese junk, 2600lm, and 4000k happens to be my preference as a more neutral white)... but yeah, you're still looking at a decent number of fixtures. OTOH, more fixtures = fewer shadows, which is a good thing. – Matthew Sep 19 '23 at 22:02
  • @Matthew You would need quite a few fixtures to mount 20 of those, or just a few very big, expensive and heavy fixtures. The best deal I've seen is $100 for a 6x fixture, and I would need at least 3 of those. So that puts me at about $400, even worse than the UFO lights. – gomennathan Sep 19 '23 at 22:34
  • Yeah, I'm not sure why fixtures are so expensive (maybe they all still have ballasts for CFLs?). Alternatively, https://www.amazon.com/dp/B0BWMMR2ZW is more light than you need in a simple kit for only $180. (5000k, though.) There also seem to be similar but smaller packages at similar price-per-lumen. – Matthew Sep 20 '23 at 15:07
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    @Matthew if those lights actually put out 15k lumens I'll buy a hat just so that I can have one to eat. They claim 250W incandescent equivalent, which is about 3k lumens, and that figure I would believe. Everyone lies about lumens on Amazon - Torque Test Channel on YouTube has tested a bunch of LED lights and found the lie range from eyebrow raising to just silly. – KMJ Sep 21 '23 at 06:10
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    @KMJ, 250W incandescent equivalence is definitely BS, especially as the description claims they "can easily replace 500W". Did you notice they're consuming 110W, though? Unless they're serious garbage, they ought to put out at least 11klm at that wattage. (133lm/W is pretty typical for "decent" LEDs. They're claiming 140, which is impressive, but not unbelievable.) – Matthew Sep 21 '23 at 13:51
  • @Matthew a common play is to quote the input wattage not the output wattage. With 110 watts maybe they're getting close to their quoted lumens, though my experience and the mismatches on their specs really make me wary. But then, buying anything electrical on Amazon is a crap shoot nowadays. – KMJ Sep 22 '23 at 02:36
  • @KMJ, what the heck is "output wattage"? I've never seen that applied to a light, and it's the next best thing to nonsensical. Wattage for lights always refers to power consumed (input). Output is measured in lumens or similar, not watts. – Matthew Sep 23 '23 at 03:35
  • @Matthew if you have 100W worth of LEDs and it takes 120W to feed the driver, you can either quote the wattage as 100W or as 120W. Reputable LED fixtures quote both: output wattage as wattage, input wattage as power consumption. Disreputable ones tend to quote the watts being input to the power supply rather than the watts going to the LEDs. – KMJ Sep 24 '23 at 03:29

4 Answers4

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Sure you can. 'Low Bay' HID lighting fixtures are available. Since they are often noisy, they can flicker, and they're more expensive to run than LEDs you might even be able to find them used on your local Craigslist or equivalent.

Don't discount LEDs so quickly though. There are low bay LED fixtures available at a similar cost that make 10k+ lumens per fixture with pretty good color rendering, instant on, better efficiency than HID, and even 0-10v dimming.

You probably also want more than a few light fixture so that there are fewer shadows. That creates a strong reason to consider LED strip light fixtures, commonly available at home stores. They can make over 1k lumens a foot, so a half dozen eight-foot fixtures will make the 50k lumens you're looking for. They are even cheaper than warehouse lighting. You give up dimming, but installing two circuits so you can turn on two with one switch and four with the other gets you nice 'three way' lighting levels for only a little bit more lighting.

KMJ
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    For my workspace, I installed about a dozen 4-foot led strip light fixtures. It was a few hours of mounting and wiring, and it's absolutely fantastic having bright lighting with almost no shadows, no noise, and good color. That got me to about 70 lumens/sqft which is a nice easy working brightness. – KMJ Sep 19 '23 at 05:17
  • Well, you're saying not to discount them, but for example this 250W MH bulb provides 25k lum for only $18. Whereas with an LED like this I would need 2-3 which is $56-84. And this LED is unusually cheap, so I suspect that it will have some kind of problems leading to hidden costs. – gomennathan Sep 19 '23 at 18:12
  • Also, if by strip lights you mean the rectangular LEDs, those are even more expensive. For example this one is 14k lum, and if I install 4 of them that's $330. Plus they weigh 12 lbs each, so that's a lot more weight to be hanging on a ceiling than just a light bulb. – gomennathan Sep 19 '23 at 18:19
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    @gomennathan You fail to include a fixture (most north of $150, cheapest I saw was claimed $99 but oops! "not available") for the bulb in your price comparison. But sure, have fun, see what happens when you skip that. – Ecnerwal Sep 19 '23 at 19:39
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    @Ecnerwal If the real cost of HIDs is in the fixture, I'd be interested in seeing that. But you have provided no evidence, just threw out some numbers that cannot be verified. I don't see why you are so angry at this, it's a reasonable thing to compare the costs of different options for lighting a room. – gomennathan Sep 19 '23 at 19:52
  • Hey, truly, enjoy the learning experience of screwing your $18 bulb into a light socket connected to 120 or even 240 VAC and watch the miracle of 0 lumens out. You can go shop for fixtures yourself, though one observation of taking a minute to do that is there are very few of them still available, relative to LEDs. – Ecnerwal Sep 19 '23 at 20:18
  • Thought you were talking about running strip lighting. You're talking about plan old LED shop lights that just happen to have strips inside them? Yes, that. I couldn't tell you how many I've left in people's attics or on site. They get the job done and they're cheap. Extension cords, splitters, 3' screws and washers to hold the chain, and... six boxes of 4' lights (8' are just unwieldy and could be two sources instead of one long one). - 330? Dude, that's dimmable (don't need that) and all fancy and stuff for like drop ceilings. Google has 4' shop lights at 41k lumens for ten dollars a pop – Mazura Sep 19 '23 at 20:25
  • @Mazura Big Orange calls them Strip Light Fixtures (see https://www.homedepot.com/b/Lighting-Commercial-Lighting-Strip-Light-Fixtures/N-5yc1vZc9h7 ) so that's the term I used. Name brand ones run 3600 lumens out of a 4 foot fixture or 8900 out of an 8 foot fixture, for about $45 and about $90, so I'm guessing that $10 one is both lying and junk. Thankfully the good ones are still not expensive. – KMJ Sep 20 '23 at 00:10
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    @gomennathan the real cost in HIDs is in the ballast and fixture. https://www.usalight.com/22-High-Bay-Fixture-250-watt-Metal-Halide-Pulse-p/ozb-22-250-mh-mv.htm for an example. They are actually getting kind of tough to find new because LEDs are the same cost at this point and cheaper to run. Again, you can't run an HID bulb without a ballast. Not going to happen. – KMJ Sep 20 '23 at 00:12
  • @KMJ It can happen, but if the bulb manages to strike (somewhat unlikely), it will promptly self-destruct. HID lamps have a negative resistance: the more current flows through them, the lower their resistance, hence the more current they want. Without a ballast in series, they will just try to see just how much current the grid can deliver, and they will lose that fight. – TooTea Sep 20 '23 at 11:57
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You can also light your workshop with pitch torches. It'll have many downsides, but should go over well with the Dungeons & Dragons crowd (not so much your insurance company, though.)

Good LEDs beat the snot out of HIDs of any stripe. HIDs take 5-10 minutes to reach full brightness, and a few bright point fixtures means lots of nasty shadows .vs. more distributed lighting. LEDs might take 0.5 seconds to fire up, and mostly that's on poorly designed dimmers rather than the LED itself (as seen when I removed the LED-rated dimmers from a set of dimmable LEDs as even that short delay was driving me nuts.)

Any HID lamp has a "ballast and starter" between it and the powerline. The starter may have to throw kilovolts to strike the arc. The lamp socket needs to be rated for that duty. If you're looking at "bulb cost" without looking at "fixture to support the bulb cost" your economics are WAY off. If you want "really bright LEDs" as a single bulb, LED HID replacements are made - just be sure to get one that's line-powered, ballast bypassed, not expecting a ballast to be hooked up. You may have to shop somewhere other than a blue or orange box store to find those, however. And it gets you the same issues with "few bright point sources lead to shadows" as actual HID.

Ecnerwal
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  • A thousand times: True. Those point-spot lights make mostly shadows. Strip led light are now mature tech – Martin Sep 19 '23 at 13:36
  • I bet if you lit your garage with mock pitch torches you would not be the first. :) – jay613 Sep 19 '23 at 14:29
  • Well, the traditional 40W single incandescent bulb in the middle of the ceiling for the entire garage comes close. ;^) – Ecnerwal Sep 19 '23 at 17:22
  • I don't think torches would work, they wouldn't provide enough light. – gomennathan Sep 19 '23 at 18:02
  • Also, the claim that "LEDs beat the snot out HIDs" is not adequately supported. I'm asking the question in the first place because LEDs for the same light output are much more expensive and seem more work to install. – gomennathan Sep 19 '23 at 18:05
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    The startup time is a significant detraction, as are the shadows. If the guy doing the archery class in college didn't show up 10 minutes early to turn the lights on, it was a very dim glow indeed from overhead while we waited for the targets to appear out of the gloom as the lights finally lit. Hard to do woodwork under those conditions. – Ecnerwal Sep 19 '23 at 18:21
  • If the compromise here is "much cheaper and much simpler lighting but you'll have to turn on the lights 10 min before you start working", that really doesn't seem that bad to me. – gomennathan Sep 19 '23 at 18:30
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    20 years ago in the old house I had a single Edison socket in the middle of a garage like you are describing. I put the biggest halogen bulb possible in there to light the whole place. It was not good, the shadows are just black, you can't make out any detail on anything not directly in the light. You cast a shadow onto your work you have to work around. I upgraded to 4 led shop lights a decade later and it was 100x better. Having non-point light is so much better. – Ukko Sep 19 '23 at 18:46
  • @Ukko Well, if you had instead replaced the 1 big halogen with 4 smaller halogens that collectively give the same light, wouldn't the situation with shadows improve considerably? And you would have the same problem with 4 point LED lights. Yes, not with LED panels, but those are also much more expensive: https://diy.stackexchange.com/questions/282003/can-you-use-a-hid-light-bulb-to-illuminate-a-garage-workshop/282008?noredirect=1#comment586470_282008 – gomennathan Sep 19 '23 at 19:54
  • @gomennathan then you would have the situation in my new to me larger shop, I have 4 of those LED wing bulb things. It is much better but I am saving up for an array of LEDs. On other thing to keep in mind is how high your ceiling is. With my 8ft one the bright bulb was constantly on the edge of my vision, the 12 ft is nicer since the light is above the line of sight. The light in question https://www.homedepot.com/p/Feit-Electric-400-Watt-Equivalent-Indoor-Garage-4-Panel-Foldable-LED-Light-Bulb-5000K-Daylight-1-Bulb-ADJ8000-5K-LED/315258709 – Ukko Sep 19 '23 at 20:22
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    @gomennathan, You don't need panel lights, you just need lots of point sources. In fact, the further apart those point sources are, the better... if they're equidistant from your work area. (Otherwise, more distance means less light.) You'll still have shadows (in fact, you'll have more shadows), but they'll be much less dark. Panel lights just make softer shadows... which is also good, but not as good as shadows that aren't as "deep". (Plus, you can add diffusers to cheap lights to get the same effect. Strip light diffusers are dirt cheap, too.) – Matthew Sep 19 '23 at 22:12
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    @gomennathan take a peek at this article https://www.woodmagazine.com/workshop/lighting-wiring/let-there-be-better-light and notice how many lights there are around the shop. This is what you want. If you need 50k lumens to light a 500 sqft space, you probably want at least 10 5k-lumen or so fixtures. Otherwise it'll be shadow city, and a very unpleasant place to do any work. – KMJ Sep 20 '23 at 00:15
  • Also, most types of HID bulbs contain mercury. There's always the risk of breaking the bulb and releasing mercury into your/the environment. – Nayuki Sep 20 '23 at 06:12
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Your specification calls for 80 - 100 foot candles.

But if you place one blindingly bright lamp in the middle of the workshop, then the area immediately below the lamp will be way above the required brightness, and the corners of the workshop will be gloomy and full of shadows.

Just getting the average brightness correct isn't the solution. You need the correct brighness across the whole workshop.

That's why other posters are recommending several lamps, or diffuse lamps (such as the LED look-alikes for fluorescent tubes).

Simon B
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for example this 250W MH bulb provides 25k lum for only $18

Hook 120V up to a mogul socket and Bob's your uncle, eh? I wouldn't do that.

I would use these fluorescent tubes here, Sylvania FO32V41. $2.38 a pop for 2450 lumens, which is more $ per lumen I'll grant you... but

  • SILENT
  • much, much, much better quality light at 90 CRI
  • run cool so not a fire hazard
  • 2 seconds to light instead of 10 minutes
  • Actual soft light, not "burn tracks across your eyeball" like HID lighting and most LEDs.
  • not a few point light sources that cast mostly shadows.
  • fixtures are actually affordable.

So how do we hook up those fluorescents?

Nail some tombstones to your rafters, hook up 120V, and Bob's your uncle, eh?

Of course not. You know perfectly well, real fluorescents need a ballast and a UL-listed fixture. Well it's the same for HID lights, to bring it full circle and actually answer your question.

Difference being, HID light fixtures and ballasts are still pretty expensive, because the're sought after by the "indoor horticulture" crowd. Nobody wants fluorescents LOL.

  • Fixture: they're free on Freecycle. They don't fit in standard trash bins, and people will let you have them for free if you let them show off their new LED lights in their shop. Be sure to compliment them. Say you'll take the fluorescents because you promised to, but you might just do what they did instead. They'll love the ego stroke.
  • T8 electronic ballasts: cheap on eBay.

The above is what I actually do in my own shop for real, so yeah, I walk my talk.

Harper - Reinstate Monica
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  • This is an answer to "what type of light should I use in my workshop" whereas the question is "can I use a HID in my workshop". You appear to think the answer is no, but since you've only offered a snide remark rather than explaining why specifically this wouldn't work, I don't think this helps much. – gomennathan Sep 20 '23 at 04:39