CurtPalme.com Home Theater Forum

ncc1701d · Joined: 08 Aug 2007 Posts: 187 Location: sweden

I have finished my hushbox and fan swaps now and have some questions.

I swapped the 4 80cfm fans to 4 papst 65cfm fans thinking that temps would never ever reach those higt temps the pj would when used in the tropics Wink

without the husbox, temps mesured inside between red and green tube = ~25-28 celcius after 2-3hours.
at the back measuring the airtemp = ~35 degrees

with hushbox with 2 extra of the old fans sucking out evacuating air into the next room: between tubes = ~30-31 degrees.
back (same place as before) = ~38-42 degrees.

Room temp about 21-22 degrees..

I don't really fear these temps now, but in the summer it gets up to 30 degrees in this room (hot, not watching very much anyway in those temps) ..

I know temps should be as low as possible, ,but are these temps ok or not?

Maybe i shoud ditch the hushbox? It really got much quiter with the new fans.

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

Did you measure the temps with the OLD fans, before the hushbox? I wonder how well the 65cfm fans are doing compared to the 80cfm fans that are supposed to be there.

Assuming the new fans do their job OK...

30C, even 42C, is not at all bad. What's more interesting is the temperature of some of the chips. I don't know how Barcos are made, but there are probably some critical STK chips or something like that. Measuring the temps of those would be more informative than the air temps.

But if the air temps around the tubes are only 30-40C, that sounds to me like a perfectly safe arrangement. I ran projectors much hotter than that. How stable is your convergence?

**kal** · Posted: Fri Feb 29, 2008 1:35 am Post subject:

IMHO, there's no such thing as "safe" temperature.

The higher the temp, the faster you'll kill the projector. The caps will dry out faster, electronics will not run as stable, etc.

A properly ventilated hushbox should keep the projector as cool if not cooler than the projector running out in the open.

Kal

KennyG · Joined: 10 Feb 2007 Posts: 254

I have done cooling mod's to Marquees, Ampros, and my XG's...the most resent has been to remove all the fans except the H-def (which I enlarged and slowed down) and the two power supply fans. I could do this because I have a 100 cfm axial flow fan located up in my attic which starts automatically when the pj powers up.
With all the mod's I've ever done, I would never make changes without getting baseline readings. If you don't have stock temp readings, how can you know if your causing a temp increase that will cause a failure sometime down the road?
Something to realize...the best place to get your temp readings is right off the heatsinks. This will tell you if the heat producing components are getting hotter, and by how much. One other point, if the heatsink is getting 10-15 degrees hotter (F) this actually means the core of the heat producing component is getting several degrees hotter than that, so if your heatsink temp has increased by 15-20 degrees, it's not unreasonable to think the core temp is up by 25-30 degrees.
When doing any kind of cooling mod's, I use 5 or 6 digital temp sensors, one is out in the tube cavity, but the rest are directly on the hottest heatsinks.
One last thing in regards to H-boxes...the air inlet WILL change the way your pj cools. If you mount three Temp sensors in different areas of the tube cavity, you'll find that these will change temps by as much as 5 degrees (F) with a front air inlet vs. a rear inlet, vs. a rear upper, or opening at the lenses...even the distance from the H-box floor and side to the PJ will change air flow characteristics, and therefore "hot spots".