Inspired by David Chapman’s You Need More Lux, I built an artificial sun.
It looks like this:
It uses:
- 1 48,000 lumen light
- 30 2000 lumen high CRI Cree bulbs (no longer available at HomeDepot and I can’t find them online)
- 1 21,000 lumen light pointed at the ceiling for ambient lighting. Closest product I can find is this.
Sitting at my desk with everything on, I measure 25,000-30,000 lux. You can easily measure lux with an app, which I suggest you do frequently if you try building one of these.
It is a little uncomfortable on the eyes, but I got used to it.
SAD lamps are ineffective. They are advertised in terms of lux (e.g. 10,000 lux), but lux is lumens per square meter. There is an inverse quadratic relationship between lux and distance; if you double the distance to the light source, you quarter the lux. Any measurement of lux that does not specify the distance is meaningless, since it is incomplete. In my testing, I have found that I only get 10,000 lux from a SAD lamp when my face is 1 foot away from it. This is not a viable set up, and it’s also not a lot of lux.
I could get more lux by replacing the Cree bulbs with higher lumen bulbs that have a more precise aim, however, most high lumen bulbs have a low CRI (color rendering index), which causes the things illuminated by them to look not-quite-real and zombie-like. I like having the high CRI Cree bulbs (CRI > 95) because they make my surroundings seem more real, as if illuminated by actual sun rather than industrial power fluorescent lights. Additionally, I like having some ambient lighting to make the contrast between the targeted area and the rest of the room less stark. This is why I have the light pointed at the ceiling and why I chose round Cree bulbs instead of more targeted floodlight ones.
If you build one of these, your project is to maximize lumens while having acceptable CRI. If fluorescent lights don’t bother you, it’s much simpler, and you can get cheap ultrabright corncob bulbs or a couple 48k power houses.
I rent my place, so I didn’t feel comfortable drilling into the ceiling and installing lights there. That’s why I built the “guillotine” that hangs over my monitors and affixed everything to that. I attached everything with chain and zip ties. Zip ties are rated to hold up to 90lbs, so if you combine 6 of them, you can be pretty confident that nothing will fall. If I owned my place, I’d have made it much more elaborate by also installing a matrix of bulbs in the ceiling for better ambient light.
I find my artificial sun mildly effective at making me feel better in the winter. It’s trivial to use and has no downsides, so it was worth building.