Garage/Workshop Lighting Design - Free Tool

While researching lighting options for my garage workshop, I discovered the online and free Visual Interior Tool. I thought that it may be of interest to other builders who are designing lighting for their workshop.

I will be building in my two car garage measuring 25' wide by 21' deep. The present lighting is inadequate with two light sockets, one centered between the cars and the other near a wall over a laundry area. If I had no choice I could make that work, but it would be cheap and easy to install a few 8' fluorescent fixtures, right? Well, a few searches on VAF (where we have some lighting professionals contributing) convinced me to approach it with some added education and thought.

Here's how I used the Visual Interior Tool:


The Settings allow for Lux and Footcandles, which are measures of light intensity. With some Google searches I found a professionally recommended light intensity for metalworking of 700 lux per sf, so I set the Units to Feet - Lux.

The tool only works with rectangular areas, so entering the Length, Width and Height of my garage was straightforward at 25', 21', and 8.5' respectively.

Workplane is the height above the floor where you expect to be doing most of your work and therefore need the light. As my workbenches will be 3' high 3.5' seemed like a good estimate. (I noted after the fact that changing this value from 2' to 6' does not change the results.)

Reflectances required more Google searches. My ceiling is flat and off white with most being unobstructed and therefore highly reflective. The walls are also flat and off white, but with shelving and other items covering much of it. The floor has a light blue, speckled epoxy finish. Based on these characteristics and my research I estimate the reflectivity to be 90% for the Ceiling, 80% for the Walls, and 55% for the Floor. Unfinished cinder block walls and a concrete floor, for example, will have different values, but estimates can be found and confidence gained when similar from multiple sources.

As described above I found an Illuminance estimate for metalworking to be 700 Lux.

No requirements for Power Density or Quantity. Under Constraints, per the instructions, I could have blocked off an area where I have a half bath, and you can impose a limit on the number of Rows and/or Columns if there are obstructions on the ceiling, for example. I didn't need to use these.

Next I selected the green plus tab at the bottom and experimented with various types of fixtures. Fortunately Lithonia Lighting is one of a number of vendor options and their products are available at Home Depot, so I reviewed their products at homedepot.com while making selections in the tool. I did have to modify the Symbol Length and Symbol Width fields as originally the icons were squared and therefore the Calculation Results such as Spacing and Arrangement were incorrect. I used the product dimensions as shown on the Home Depot website.

I settled on the Lithonia Lighting 4 ft LED Strip Light, model MNSL M6. They're $119ea at HD but I found them for $101 elsewhere. That's not cheap, but they only require 18.5 watts, are rated to last 50,000 hours (23+ years!) and have a very high Color Rendering Index (CRI) of 89. CRI measures the ability of a light source to reproduce the colors of various objects accurately in comparison with an ideal or natural light source, 100 being optimal. Also, being in Florida I don't want lights that create a lot of heat.

I plan on installing nine of the LED lights as the row on the far left has a bathroom, washer/dryer and water heater below, in addition to a kayak hanging down that would block the lights. Per the results I should get 732 lux which just exceeds the 700 lux suggestion I found for metalworking. I also found a footcandle estimate for scroll woodworking of 70. Changing the units to footcandles and illuminance to 70 results in the same recommended configuration, providing some added confidence in the results.

I'm sure it's not perfect. The results are only as good as all of the estimates I made or borrowed from others. But, it should be a lot better than my original plan of simply putting up a few 8' T8 fixtures, and it gives me measurements for placement which should help coverage and minimize unwanted shadows. I was surprised to learn how much lighting is recommended, and with some of the fixture/lights I selected the configuration included upward of 30 4' fixtures!

I have an electrician coming to help, and plan to have the lighting, electrical outlets, and compressor each on a different circuit/breaker. I also plan to have multiple switches for the lights so they don't all have to be on/off at the same time.

Feedback is, of course, welcome, and especially from any of the pro's in the event that I am propagating any misinformation.

Thanks!

Chris

Just put up Lithonia T5 lighting and it is unbelievable.

I second the T5s. I got mine from HD. Four fixtures--four bulbs each. They were $100 each. Bulbs are cheap on-line. In a 24 by 24 garage it is brighter than in my house.

I have 9 canned lights in there as well (put in before I found the T5s). I can barely see with the canned lights on. Flip on the T5s and you can't even tell the other lights are on.

Not the cheapest option, but possibly the nicest.

ken

Sounds like the exact same ones I Got at Home Depot. Changed 5, 4 foot, 4 bulb fixtures and it was amazing.

My daughter came walking up the driveway this summer when it was full dark. I had the garage door open.

Her comment was that I looked like I was in a lantern. I will take a picture of the one of the garage windows from outside at night. It is 3-4 times as bright as the inside of my house.

cheers
Ken

Thanks for the feedback. T5's, as well as T8's or T12's are certainly options, but pure brightness is only one factor. Quality of the light is important and I really like what the LEDs provide, though it will be interesting to see if my perception is the same between the showroom and my garage.

I selected some T5 fixtures in the tool and immediately see that fewer fixtures are required and they are less expensive. There's definitely a significant difference in cost. It is cool that there's something out there that can help make a more educated decision and the user can determine what variables are most important when making their decision.

Thanks!

Chris

Update?

Chris, Did you install your lighting (T5) as planned? How do you like it? Any drawbacks thus far?

Thanks,
Matt

Used the Visual Interior Tool also

Hi Chris,

I used the Visual Interior Tool also. I've got a 4 car garage and I used the Visual Interior Tool to get an idea of the lux level a particular layout would give me. I chose a lux level based on OSHA standards for "detailed work" for workers "over the age of 45" (I easily pass that test...). I found online some typical reflectance values for paint and concrete and used Lithonia SB 2 32 120 GESB lights with some Phillips T8 bulbs (6500K) all from Home Depot. I wired the lights up so I could turn them on in banks of four. The lighting is fantastic. I never have a problem with lighting now.

Below are some pix showing when I was installing the lights and then after I had the walls and ceiling insulated with foam, dry walled and painted (My QB arrived two weeks later). I also installed a Mitsubishi Mini-split heat pump (MXZ-2B20/MSZ-FE09x2). The mini-split works great. I got the system up and running just before summer hit. I think I said something that has never been said in the history of Houston in the summertime: "Jeez, this garage is too cold!!"...

I also plumbed the compressor lines in the walls too. Makes for a nice, clean setup.

I hope this helps.

Jeff

Excellent job folks. I have lit many hangars/garages with these combinations of products. We use the professional version of Visual, I actually know the designer of the software, and sell the Lithonia brand in our market area of Oregon and SW Washington, but the free version is just fine for simple spaces.
One caution, the reflectance values rule the roost. Remember, you will have tool boxes, shelving, and other stuff in the way. All this "stuff" can dramatically change your light levels especially if you are relying on the walls and floors. I default to 70/30/10, and rarely go higher.

Carry on.....

When looking at the LITHONIA part numbers in the APP, any idea what the 4 Tube, 8 foot, 4 bulb T5HO strip lights are?

Part num: TZ 2 54T5HO MVOLT 1/4 GEB10PS $99 at Home Depot

I looked and looked but didn't see them listed. I'd really like to retrofit my hanger with some of these and it would be great to see how they would plan out.