SAD Light Therapy Box (DIY)

My wife has always complained of having no mojo when the daylight hours get shorter and overcast Winter skies seem forever present from November to March. If you have ever looked at therapeutic Seasonal Affective Disorder light boxes as a treatment for SAD, you know they run from about $50 for very small ones to over $300 for larger models. From my research all of these devices try to provide over 10,000 lumens and should be used about 30 minutes or longer per day to provide enough light to counteract the effects of SAD. With that criteria in mind, I set out to see if I could construct SAD Light Therapy box as a Christmas gift for her. Below are the recaps of my efforts at version one and the final version that she uses today.  Skip to the photo section below for a quick review of the steps taken to build the final version of the light box.

495733_METAL RETRO RED BASKETWhile researching these devices, I came across a LifeHack where a brother made one for his sister using a wooden file box from IKEA and had to drill the box for the bulb holder mounts. While I could have gone that route and my initial hardware store purchases were of three massive fluorescent bulbs and mountable cleat bases, I 495733_METAL RETRO RED BASKETquickly found out that the massive bulbs also took a massive base known as Mogul type for which the standard bases I had bought would not work. I liked this design as I could get the lumens I needed with only three bulbs, which meant less effort to do the mounting in the box that I found to be base of the device. Speaking of the box, I located it at World Market and it is a red metal picnic box for lack of a better description. The dimensions are 14.6″W x 11.2″D x 7″H with the lid and opening being on the 14″x11″ side.

After returning the mogul bulbs and standard bases to the home improvement store, I spent a lot of time wandering the electrical and lighting aisles trying to come up with much easier design that would not involve drilling and mounting bulb bases or elaborate electrical wiring. The simplest design I could come up with was to mount power strips in the box with double sided tape and use electrical outlet to bulb base adapters to hold the bulbs.

IMG_0769Trying to keep the cost as low as possible, I went to Wal-mart to find the power strips and bulb adapters. I found four black standard six outlet power strips and eight bulb adapters as that was all the store had in stock at the time. I got home and mounted the power strips side by side with the double sided tape and placing the bulb adapters on the power strip outlets that would give me room to plug in the other power strips to the primary power strip that would received external power.  This design ended up having odd bulb placement and the power strips in the bottom looked pretty ugly, so I took some white poster board and cut it to cover the guts while cutting round holes for the bulbs to screw into the adapters. The bulbs chosen were 100W equivalent compact fluorescents with each one providing 1,600 lumens for a total lumen output of about 12,800. My wife was happy with the gift and used it for about a week, before I started realizing there were some design flaws.

What I did not like about the initial build design were, the bulbs being non-symmetrical, and the double IMG_0770_2sided mounting tape quickly giving into the forces of gravity and the bulbs flopping to down with the unit sitting on one end to provide light out to the room. Part of the problem with the bulb placement was due to the power strips. The ones I had bought had a hump on them at the end where the switch was located. This prevented using the outlet closest to the switch as the bulb adapter was too wide to fit due to the hump. I also did not like that I had to use four strips when two of the appropriate size, with adequate spacing and no hump, could do the trick.

IMG_0784So design and build of version 2 came about by finding two Philips brand power strips that had six outlets, with one being spaced out further on the end for transformers and no hump near the switch. Mounting these two power strips along the 14″ orientation allowed symmetrical bulb placement, but there was little if any space to daisy chain the second power strip into the first for power. Given there was not a need for electrical grounding in this project with light bulbs, the plug of the second power strip was trimmed of its grounding leg to fit in the small space between two of the bulb adapters on the first strip. To solve the mounting tape problem, self drilling sheet metal screws were used to mount the power strips to the bottom of the box with care taken not hit the wiring at that end or the plug on the other end. This design looked clean enough that there was no need to hide the internals with poster board as done on the first design. On the electrical side of things, the cord from the power strip was pretty short and plugging in and unplugging version one as an on off mechanism was not convenient. So with version two, I bought an in-line electrical cord switch and cut the very end of the cord from the power strip at the plug. Then I took an old PC power cord and cut of the end that went into the PC off. I soldered one leg (wire) of the two cords together and connected the other legs to the switch connections. So now the light box can be left plugged in and the switch makes it easy to turn on and off. Finally, one feature that I have not mentioned that I wanted from the start, was the ability to put the cord into the box and close it for storage, but since the wife has been using it each day there has not been a need to store it away to test that feature.

Project Parts List and approximate costs ($75 total):
Picnic Box ($25 World Market) – Wooden or Metal Box with enough space to accommodate power strips with bulbs and adapters
Philips Power Strips ($3.50 each x 2 = $7 Ollies)– Ones with more space between outlets  are better as are models that have the switch located on the side or at a minimum flat across the top – Possible Amazon Basics alternative
AC Outlet to Bulb Adapters ($1.27 each x 8 = $10.16) – Should be available at most home improvement stores or Wal-mart
CFL Bulbs (4 pack 23W 1600 Lumen Great Value Wal-Mart $9.88 x 2 = $19.76)– CFL or LED based on Lumens needed and available sockets. (Note: First batch of GV/WM bulbs had almost four bad ones, so save your receipt for an easier exchange.)
Mounting Hardware ($1) – Screws or another mechanism to hold power strips in place in the box.
In-Line Cord Switch ($5) – Standard Rocker Type with pass through of one leg.
Extension to Cord ($0) – Left over PC power cord.

To-Dos:

  1. Line the inside of the box with white contact paper or make another internal cover from poster board like version 1
  2. Check the output of UV light
  3. And depending on the results of #2, procure and install some sort of diffuser with UV filtering capabilities (I am thinking something like plastic drop cloth using a rod with a right angle on the ends to place in holes on the lid edge to the far side of the light compartment, as this should support the diffuser drape and also give the unit some stability while on standing on its side)

Update: January 17, 2015 – A quick test of UV output with some UV activated Transitions eyeglasses showed there was some UV output from these bulbs.  The solution I found was to obtain some clear UV filtering film from Tinted Atmospheres where I had my Mazda 5 windows tinted.  The film was not cheap, but it appears to be preventing the output of UV when tested with the glasses.  To mount it, I cut a 13 1/2″ square of the film and used some very small button magnets to hold it in place on the front opening of the light box. See step 7 below.

Step one – find an appropriate metal box
Step 2 – Mount the power strips from outside bottom. The markings on the right were the original location I planned to use, but decided to try and get equal spacing with the inner dimensions of the box based on measurements from the already installed power strip on the left.
Step 3 – Daisy chain second power strip into first and insert bulb socket adapters with spacing appropriate for bulbs.
Step 4 – Install cord switch and extended cord.

 

Step 5 – Trim poster board to correct size and cut holes for bulbs. An easy way to determine the places to cut holes is to use a dry erase marker and put ink on all of the socket edges, then press the poster board onto the sockets and you should have some very light circular marks showing where the holes need to be cut. Additional poster board was cut to line the inside of the box on the sides.
Step 6 – Install Bulbs and test.
Step 7 – Diffuser installed. Diffuser is made of Contact Paper brand translucent shelf liner with no adhesive and a layer of UV blocking automobile tint film. The two layers were held together with hot glue.  Some small fiberglass rods salvaged from a hover disc hoop was cut with about 1/3″ extra length based on the width of the box. Then these rods were threaded through the diffuser at the edge and in the middle and the openings and rods secured to each other with hot glue. To install the diffuser the rods are inserted under the lip of the box on one side and flexed to allow them to catch on the opposite side lip. This holds the diffuser in place and provides a bow shape that allows the heat to vent to the top and keeps the diffuser from touching the bulbs.
Final Step – Lightbox ready to store with diffuser rolled up and placed between the light bulb rows.

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