AE700 Cooling system

Discussion in 'Displays' started by Brad-F, Feb 11, 2006.

  1. Brad-F

    Brad-F Stunt Coordinator

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    I have made an observation about my new AE700 and the way it cools after it has been in use..

    When I hit the big Power button, and then it Ok to confirm "Power Off", the AE700 goes into its cool down routine.

    I can hear the fan inside speed up.. and I can feel hot air being pushed out of the front exhaust outlet. So far so good..

    However, I have stood there and felt the hot air coming out, and at the time that the cooling down routine stops, the air coming out is still hot!

    I want it to keep blowing!

    I want the fan to keep blowing until the air coming out is close to room temperature! Why on earth would they have designed this thing any other way?

    It seems like a major design floor to me, that this cooling system stops, while the inside of the machine, (namely the globe) are still VERY hot.

    Is it possible to adjust how long this sequence runs for?
     
  2. DanHal

    DanHal Stunt Coordinator

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    Brad,

    The damage will come from restarting the unit while the bulb is still hot. As long as you shut down the unit per instructions, you shouldn't have any issues. I believe the sequence is all controlled via the projector, so you would have to figure out a way to flash the memory and change the cooling down process, or rig up a switch that would turn on the fan seperately. A non invasive idea would be to simply rig up a small computer fan that you could place near one of the vents to push or pull the air through the unit after the unit's fan shut off. My suggestion though, just let it cool down normally, and don't turn it back on for at least an hour or so.
     
  3. Brad-F

    Brad-F Stunt Coordinator

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    But what is better, cooling it to room temp, or leaving it hot??

    I mean, if what you say is correct, and there is only a problem if you turn the unit on again, what is the point of having the cooling sequence at all. Why not just turn it off at the wall? Assuming I don't turn it on again it would not hurt the unit. Right?

    And if you are suggesting that there is some point where the temp is ok for the active cooling to turn off, what is that point? And how can we be sure that it is not turning it off too soon?
     
  4. DanHal

    DanHal Stunt Coordinator

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    Wowsers! I'm no expert here, but this is my general concensous.

    Projectors have a cooling down process when you turn off the unit to get the bulb down to an acceptable temperature where heat damage and glass distortion won't occur. If you simply unplug your projector from the wall while it's still hot, the glass bulb may cool unevenly and cause stress cracks. If this is the case, I don't know. The number one reason why there is a cool down cycle, to prepare the unit for an immediate restart. Fortunately, most home theater projectors are not going to be subjected to back to back shut downs and restarts like business projectors.

    Now, this is where there is a little debate. I actully would rather have my projector shut down and cool naturally. If I shut off my unit, it's not turning back on for at least two hours. I don't need the capabilities of an immediate restart. Some people think letting the bulb cool down naturally is better than the forced air cool down. The real damage will occur when you restrike the bulb while it is still hot. Most bulbs have to be below 200 degrees celcius for a restrike to occur. For example, turning off the projector and turning it back on within an hour or so. Ideally, projectors would turn off and let the bulb cool naturally, and only run a cool down on bulb striking during the startup process if the bulb isn't cool. Why this is the standard in the industry, I'll have to let someone more informed than me answer that.

    Now, I'm not 100% sure of how Panasonic's cooling down process works. I've never really paid much attention to mine, but I really wouldn't worry about damaging your bulb as long as you follow the instructions in the manual. You could time the cool down sequence to see if it is temperature controlled, or simply a certain amount of time.

    Now, that was way too technical for the average person. My final short advice, shut off your projector per the manufactors instructions. If you ever unplug your projector accidentally or have a power outage, let your bulb cool to room temperature before restriking.
     
  5. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    I use a secondary portable fan that always circulates air close to the projector. It actually keeps the running temp of the projector cooler by 2 to 3 degrees during normal operation.

    Down side ... additional fan noise ...

    Regards
     
  6. Brad-F

    Brad-F Stunt Coordinator

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    "A person regarded as obnoxiously puritanical"

    Really? I'm just a dude interested in looking after his projector.
     
  7. Brad-F

    Brad-F Stunt Coordinator

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    Michael.. That is interesting.. is the potable fan a normal desktop variety? And where do you aim it? Just over the unit, or specifically into an air intake vent?

    Also.. How do you check the temp of the unit? How do you know it is 2 to 3 degrees cooler? Is there a menu setting to check this?

    If keeping the unit cooler is a good thing (which it seems to be from what i have read), then beefing up the cooling is a fine idea.

    Perahps I could rig up a PC fan to just outside the unit, blowing air in. There are some very quite PC fans about now..
     
  8. DanHal

    DanHal Stunt Coordinator

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    Yes, if you aren't able to shut down the projector per the manuals instructions, wait at least an hour for the bulb to cool completly to room temperature before attempting to restrike the bulb. It probably could be restarted sooner, but I wouldn't risk it.

    But what I've really gotten out of this lively debate is that the cooling down cycle on the projectors really isn't to "cool down" the unit, it's there to cool the bulb down to a cool enough temperature to where the bulb can be restruck again for a restart. Like I said earlier, I don't know why it's not the other way around, perhaps someone else can chime in on that.

    Wowsers, is that really the definition? I guess I've never thought much about it, I think I must have heard it from one of my old cartoons. And, no I don't watch cartoons on my projector. . .hehehe.

    This is gotten way over my head, now you have me second guessing myself. :) The temperature of the unit can be accessed through the OSD under unit self check I believe. Check your before and after temperatures if you do rig up some sort of a cooling unit, and post your results please!
     
  9. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    My projector is mounted on a shelf at the back of the room. The second fan is a typical $10 portable clip fan clipped to the shelf. It circulates air around the back of the projector ... since there is not much space between the rear of the projector and the back wall.

    The Benq projector has operating temp shown in the user menu system. I have run it with and with out and the temp changes from the usual 41/42C to 38/39 C with the fan in action.

    Regards
     

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