CurtPalme.com Home Theater Forum

AFryia · Posted: Fri Apr 04, 2008 1:34 am Post subject: More Hush Box Questions

I'm building a hush box for my CRT.

The ceiling is finished so I need to exhaust the box out the side or something. My concern is the front intake will pull back in the warm exhaust.

1) Anyone have pictures on hush box ventilation routing or ducting ideas?

2) how do you keep the warm air inside the box from being pulled forward to the front intake grill? (G70 pulls air from around the lenses and exhaust out the back) The whole PJ is in the box. It's like swimming in your own pee Neutral

3) how do you thermally control the exhaust fans?

Anthony

ecrabb · Posted: Fri Apr 04, 2008 2:52 am Post subject:

This for your G70?

SC

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

Can you run the external exhaust line out the back of the hbox? That way it'll pull the warm air blown out of the G70 out of the hbox. If you have an intake at the front (around the lenses or similar), you'll get cool air in the front where the G70 takes it in. That would work perfectly.

Controlling the fan: easiest is to switch it so it turns on when the G70 turns on. Or you can use a thermostat (I used the thermostat for a ceiling vent fan, $16 at HD) to turn it on when it starts to get warm in there.

Ile · Posted: Fri Apr 04, 2008 12:09 pm Post subject:

You can separate hushbox to two sections, cool section to front and hot section to back. That's how I made my previous hushbox and also next one. This also improve cooling, because duct fans helps projector own fans.

In my previous installation I used silencer in input duct, because it was pretty long.

greg_mitch · Joined: 03 May 2006 Posts: 5320

So what is the airflow pattern for the XG110? I read that it is better to keep the cover on inside a hushbox for the NEC's.

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

XG's don't have a simple front-to-back airflow like G70's. There are fans all over the place. Yes, generally it's best to keep the covers on as the airflow was designed to work with the covers on.

The best way to cool a ceiling-mounted XG seems to be to put a "plenum" on the base (covering all the air holes on the bottom), and suck air out through that. It also helps to reverse the side fans, which blow air *out*. That works fine for a floor mount, but for a ceiling mount with an extractor on the base (top), those fans fight against the extractor fan.

AFryia · Posted: Fri Apr 04, 2008 10:23 pm Post subject:

Ile · Posted: Sat Apr 05, 2008 7:22 pm Post subject:

AFryia · Posted: Sun Apr 06, 2008 10:02 pm Post subject:

OK. I installed the rough hush box and fired up the PJ for a test. so far so good.

I notice some light being projected to the inside surface of the box just above the lenes. It doesn't appear to interfere with the image.

I plan on making the front a separate removable piece so if I change the PJ tilt or something I just need to make a new front piece.

What do you look out for in designing the opening/aperture for the lenes and projected light?

Ile · Posted: Mon Apr 07, 2008 8:06 am Post subject:

Where that light is coming from?

I'm going to use similar lens sealing what my previous hushbox had. Hushbox have few mm bigger holes what lens diameter are and then I cut tight seal from cellular plastic (hiking matress) and glue that to lens opening. It's air tight, but makes focus tweaking possible.