Has anyone tried putting fan on top of projector with air flowing in front of the piece of lexan or glass?This might eliminate the need to cut slot in front of lcd panel thus keeping dust off fresnal and lcd.If you made projector a little taller the fan could be mounted inside .

One problem I'd think that wouldn't be compensated for is that lcd will heat up when it is hit by of axis light. The light bulbs are far from being a point source, not to mention that not painting the lighting chamber and flashing would just add to the problem. If you're not directly cooling the lcd, you run the risk of killing it.

I had modified my box to include a heat shield. The bulb area was cooled by one evercool fan. The area between the heat shield and collimating fresnel was cooled by one squirrel cage fan. (25 CFM) The fan was mounted on the top of one side with the air inlet on the bottom of the opposite side. I made a single piece top, so there was no inlet between the LCD and fresnel. The temperature got to 100-102F, and stayed there very steadily even when adjusting the speed of the evercool. This is obviously, not a good senerio.

I then covered the inlet hole for the squirrel cage fan, then put the top on that had the cooling slot so air was only drawn in between the fresnel and LCD. This senario give me a temperature that is 10-11F above ambient room temp. Today by basement was 66 and the temp between the collimating fresnel and LCD was 77F.

My conclusion is that if you don't draw air between the LCD and fresnel, the temperatures will be close to the accepted maximum value of 105F. In the summer I could easily see temperatures exceeding that value.

-gs