I'm moving into a new space. It's a very nice loft, the only drawback being the washroom is uninspiring. Since they are inexpensive and use a low heat and energy LED lamp, I was wondering about the practicality of using a LED projector, either off the shelf or constructed, as a light (primarily)/information/entertainment source. For example, it may be located over the door and projecting onto the opposite wall, and in addition to being a general light source, would be viewable when taking a bath or, ahem, sitting down. It could display nice nature scenes, with weather and light current events overlaid, connected to a home media server that will already be on all the time.

A few issues I can think of..

* It may not be possible to quickly turn on / off the projector when someone enters/exits the room
* The energy use may be too high to responsibly use - what is the consumption compared to a regular light?
* The room may be too humid and cause the projector to fail
* The lens may not be flexible enough for the desired distance
* It may not project enough light to be useful (though it could be augmented with switch lights when needed)

Thanks for any comments!

(I numbered your issues to make them easy to address.)
1. Being able to turn on and off instantly is a strong suit of LEDs. You could sit there and flip the switch on and off like a little kid if you want.
2. "Lumens per watt" is how people generally compare efficiency of light bulbs. Incandescent (regular bulbs) are very inefficient at ~13 lm/w and CFLs are around 75 I think. LEDs are very efficient. A brand and model of LED that's popular here is the Cree Q5 which is suppose to put out a minimum of 107 lm/w (at it's most efficient). Cree's newer LED, the R2, is minimum 114!
3. Here's what the Cree data sheet says about humidity...
Click to view attachment
It sounds like once they're soldered it doesn't matter how humid it gets.

4+5 is a function of which projector you choose/how you build it.

There's 3 people who are working on LED projectors (I used to be a 4th, but I'm a quitter)...
LED PJ using 90 CREE P4, HDMI controller and 12.1" Hitachi LCD <- DIY projector using Crees
XGA LED projector, LED projector <- Commercial projector converted to LED projector using a single Cree (more planned)
Projector using an OSTAR LED, 1120 lumen <- Osram brand super bright LED into a commercial projector

Thanks, Hirudin.

This is helpful data. But do you think it would work?

I'm curious if anyone has done or seen this anything like this, or knows of a particular device that would be well suited. For example, I've read that the Mitsu LED projector doesn't come back on from power saving events, so it wouldn't be a good choice.

I'm not sure I know what you want it to do...

You want to project nature scenes onto a wall pretty much all the time (or at least while you're awake)?

If that's the case, LEDs would be good, but I think MH might also be a viable option. If you're leaving it on for long periods of time you'll probably want it to run cool too. A 150 W ceramic MH bulb might be perfect. Or a Xenon bulb, (car headlight) like in Weldonjb's Mastersuite Projector.

If you can live without the weather updates, you could ditch the LCD portion of the projector (which blocks a LOT of light) and use transparencies or something. Actually, maybe retrofitting a slide projector with very bright LED(s) might be a very good way to go! I bet some you could find one that has some kind of timer to automatically advance the slide every few minutes. Load it up with nature photos and you're set.

It would only be activated as a light source, eg. motion detection.

You're right that it would a lot simpler without the computer (LCD/etc) projected display, but that's really what makes it interesting to me (for more than just weather updates).

I'll keep my eyes open, it seems to me that interactive walls will be a mainstay soon, but I don't know of any economical, accessible product yet. I'm not much of a hardware hacker (my past attempts were pretty dismal) but I figured the community here would have some insight.