Workshop lighting - how many ft-candles?

[JohnJL]

Ft-candles is a technical term and Porsches get worked on so pls pardon the tenuous forum choice.

I need to finalize the electrical plan for my addition. I'm putting on an 8-car (36' x 40') workshop on the house that will serve 1/2 for daily driver/lawnmower and 1/2 for engine and metalwork/mancave. It will have a lift.

I need to finalize the electrical plan. I have the machinery/bench/compressor/other plans covered but am looking for help with the lighting plan.

I've read I want anywhere between 27 and 70 ft-candles of light. That's a huge range and as the fixtures arent free I need to narrow it down. Ceiling is 9' (except over the lift where its 12')

The architect planned 8 x 4' double flouro tube shoplights. However the GE site suggests I need 21 fixtures to get 50 ft-candles (with 32w 4' double-tube shoplights) That 50 ft-candles was a WAG.

Any help and specifically ft-candle guidelines would be much appreciated.

[Mo_Gearhead]

Workshop lighting is exactly like sex:

A LOT - is good
MORE - is better
TOO MUCH - is just enough.

Not real scientific ...just sayin'....

[bart1]

I happen to have a meter here at my desk. Just checked and I have 75 ft-candles on my desk. Looks like I currently have 5 working 4 ft tubes on a 9 ft ceiling above me with diffusers. Dunno if that helps. I think your reflector/diffuser could help a lot.

[lindy 911]

I disagree that more is better. You can have too much light and it will turn your evening in the garage into a headache; literally. I suggest you ditch the 4' florescent shop lights, they are very old technology. Look into a T-5 lamped fixture that has five lamps with a stainless reflector. Three of those in the main work area would be plenty. If you can post a floor plan of your garage I can lay it out on the computer and tell you exactly what to expect. I need to know where the primary work surfaces are going to be and where the ceiling elevations change.

My garage is four car but with a two car double door. You have to stack the cars in end-to-end. This gives the look of a two car garage from the street which is more in scale with the rest of the house. I have two of the five lamp T-5 fixtures mounted at 9'-0" AFS and they are all I care to have. There is plenty of light on the work benches and if you paint the floor a very light color it will reflect light underneath the car as well when it's on the lift.

Lighting is what I do for a living; see attached.

Lindy

[dad911]

Std. Fluorescent won't fire when it's cold. I think the 'High Output' fixtures and bulbs will work in colder temps.

Consider placement around the lift, to prevent shadows.

To leave your options open, I would consider leaving tails/junction boxes in the ceiling for flexibility.

I would also rough with 3-wire (2 switches, 2 circuits)

Don't forget the 220 circuits for lift, compressor, and welding equipment. Be sure to specify 'high track' doors, and torsion springs with the garage door company. Not much more to install.

[David]

I have twelve 4' double T8 fixtures in my 23' x 43' garage plus a 13th over my main workbench. I set them up on two circuits so I don't have to have all the light all the time. I had 8 before my latest upgrade and it wasn't quit enough.

[GH85Carrera]

I agree with the more the merrier. I have 5 - 8 foot twin bulb lights in my work bay. Three of them are on a separate switch so I don't have to have them all on. I can go to "Turbo mode" if needed. I find most of the time I have them all on. I want even more for waxing and cleaning.

[lindy 911]

A four lamp T-5 fixture will have about 5 times the light of a standard florescent 8' shop light. One fixture over a work bench at 8'-0" mounting height measures at 188 foot-candles. The three 8' strip T-8 (standard) measures 23 foot-candles. Not a tough call.

Lindy

[David]

I couldn't justify the cost difference between T8's and T5's.

Checking Home Depot online for 4' bulbs: a 32W T8 is $1.50 and a 28W T5 is $7.79.

We have 4', 54 watt T5's at work. They're about $8 per bulb when we buy a case! And you can't buy them just anywhere.

[JTL]

My 4-car garage is ~1,000 ft2 with ~8ft ceiling. The PO only had 2 60W bulbs to light to entire area, LOL. I quickly installed 16 4ft double fluorencent fixtures w/T8 bulbs from HD. The wiring was easy since there is an attic directly above. A breaker box with spares is already installed in the garage with even a 240VAC outlet; welder or lift Hardest part was removing the plywood floor pieces in the attic.

I need a lift badly but don't think there is enough clearance?

The lights were a really nice improvement and now I can actually see what I'm working on. However, within about 2 years the lights started going out. I found the el cheapo ballasts were the problem. These fixtures were only $12-15/piece. Fortunately I found replacement ballasts online for $8/pc and have been replacing them as the old ones go out.

Now, one negative factor of having a nice garage is: Wife is a PO'ed because I have a project ongoing pretty much continously.

[kodioneill]

I would listen to Lindy, he knows what he's talking about.

[kodioneill]

Originally Posted by lindy 911

I disagree that more is better. You can have too much light and it will turn your evening in the garage into a headache; literally. I suggest you ditch the 4' florescent shop lights, they are very old technology. Look into a T-5 lamped fixture that has five lamps with a stainless reflector. Three of those in the main work area would be plenty. If you can post a floor plan of your garage I can lay it out on the computer and tell you exactly what to expect. I need to know where the primary work surfaces are going to be and where the ceiling elevations change.

My garage is four car but with a two car double door. You have to stack the cars in end-to-end. This gives the look of a two car garage from the street which is more in scale with the rest of the house. I have two of the five lamp T-5 fixtures mounted at 9'-0" AFS and they are all I care to have. There is plenty of light on the work benches and if you paint the floor a very light color it will reflect light underneath the car as well when it's on the lift.

Lighting is what I do for a living; see attached.

Lindy

Hey Lindy , how many watts for those lamps in the stadium? Are they MH or sodium?

[Dantilla]

I assume you are painting the ceiling and walls bright white?

That makes a massive difference in overall lighting.

Also- Most garages put the light fixtures directly over where the cars sit- This causes shadows. Far more effective to add one more fixture, and place them between cars. This makes for much more even lighting throughout.

[lindy 911]

The fixtures in the photos are 1500 watt metal halide with a parabolic reflector. The top pic is of the Reno Aces Stadium which has 230 fixtures and the bottom two are of the Ballpark in Arlington which has 800 fixtures.

Lindy

[RWebb]

you want enuff light so your pupils are near their minimum size - this means your eyes will have their max. resolution if you are old (your eyes cannot focus well up close with age b/c the eyeball itself gets 'stiff' -- the eye changes shape to adjust for distance)

BUT you want NO glare

I use a combination of [1] area light, [2] task lighting and [3] moveable "task lights"

[Superman]

how old are you?

[JohnJL]

Thanks guys. Attached here is a PDF of the space. I've pencilled in some notes.

Lindy, I looked up the T5 units on Sylvania and on a neat calculator I found online. Those 5-tube 4' units are super bright, might I be better off with 2- or 3- tube units disbursed over the room more evenly?

I'll be painting the walls and ceiling white, floor a light grey urethane. Ceilings are 8' all around.

I'm 36.

Here's the scan...





What

[PCA7GGR]

The "TajGarage"

[David]

Originally Posted by PCA7GGR

The "TajGarage"

Or "Garage Mahal"

With that setup, I'd definitely spring for the T5's!

I'm not the expert here but if it was me, I'd put two double 4' T5's per bay and a few spread above the work bench area with a couple more in the bay where most work is conducted. I'd also have 3 or 4 circuits to adjust the lighting.

In my garage, I split the circuits between cool white bulbs and shop light bulbs. It makes for some weird colors, but I spend a lot of time just chilling in the garage, having a beer, and listening to the stereo or watching the big screen so sometimes I don't want a lot of bright light.

I also have a few switched outlets in the cabinets on the same circuit as the main lights so when I turn on the lights, the stereo, battery chargers, etc come on.

Also consider where you might put a TV and where you're most likely to view from. You don't want any lights directly above the TV or directly above your line of sight to the TV.

[lindy 911]

John,

Check your dimensions. Either the 36' is too short or the 40' is too long. You are most interested in the "workshop" I assume. I will lay this out this evening and post the results. The IES recommends 75 FC for factory assembly line uses; that sound good to you?