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I use a 4" "project fan" that I purchased at radio shack to supplement the fan in my lcd projector. I have it placed in front of the exhaust fan where it helps to pull more air thru the projector. It is 110v version and is plugged into a switch and automatically turns on and off with the projector. I think that it is a good idea to use one of these if you have an lcd projector. My model projector tends to burn up polarizer plates, which can be a costly repair.
 

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Sorry, i could not resist. It is best to remove hot, than add cool. At least that is what i seem to recall works best. Blowing adds dust and other nasties to the mix at high speed.
 

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I have an in-line duct fan that pulls heat out of my hush box (it sucks right from the outflow on my Plus DLP fan). Pulling hot air away is better than blowing towards it.




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Lex MC1/Sunfire CG/Hales Rev3's x3/M&K SS150 tripoles/Quadscan/Plus UP1100/Homemade screen
 

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Assuming 'chrisl' is considering building a hushbox...


I'm starting to design a hushbox for our newly acquired LT150, and leaning toward using a couple of 12V squirrel cage blowers located on the inlet side to pressurize the hushbox. My thinking is this: I want to filter the air supply, and by pressurizing the box any leaks will be clean air leaking out, not dirty air leaking in. Blowers instead of fans because they can overcome higher static pressure, a problem with noise reduction labyrinths and air filters.


In general, you want your air flow path to match the projector's -- it isn't going to help anything if your auxiliary fan is blowing against the projector's exhaust fan. And I'd think you want the air flow capability of the hushbox fans to at least equal those internal to the projector.
 

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Quote:
Originally posted by OldDave:
My thinking is this: I want to filter the air supply, and by pressurizing the box any leaks will be clean air leaking out, not dirty air leaking in.
Of course, this is exactly the principle used by electronic "clean rooms" and paint booths. It's easier to filter the air at the intake of the fan.





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DVI/HDCP makes your HDTV not ready
 

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Chris,


As long as you ensure that the total input or output

of the fan is going toward augmenting the air flow

through the projector - it really doesn't matter

if the fan is an exhaust fan or inlet fan.


If you wanted to be real picky - then the inlet fan with

cooler and hence denser air would provide more mass flow

rate - but that effect is too trivial to worry about or

base a decision on.


Dr. Gregory Greenman

Physicist
 

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OldDave and others,

I hope you can keep adding ideas on a hushbox for the LT 150;

Looks like I need one, and smaller the better.

BTW, the inlet side is the same as the outlet side (there is a vent on top and bottom also).

How does one you ensure that the total input or output

of the fan is going toward augmenting the air flow

through the projector?


"Inlet fan with cooler"


How does that work?


Thanks.



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Jim Story

Live long and Prosper
 

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Quote:
Originally posted by Jim Story:
BTW, the inlet side is the same as the outlet side (there is a vent on top and bottom also).

How does one you ensure that the total input or output

of the fan is going toward augmenting the air flow

through the projector?
While there is a small inlet near the outlet port, I believe the main inlet is on the opposite side of the projector. I'm planning to have the air flow originating from this side of the projector, with the exit port aligned with the projector's outlet fans -- I don't want any of the hot exhaust air recirculating inside the box.


I'm still torn between hanging the LT150 on a small plate internal to the hushbox using the three M4 screw points, or having the normal top of the projector rest on three or four small pads. The second method would be better if there are occasional road trips in the thing's future.


You mentioned you wanted a small hushbox -- how small?
Quote:


"Inlet fan with cooler"


How does that work?
The original phrase was "Inlet fan with cooler, and hence denser air". Morbius' comment was than cool air is denser than hot air, and because of that a fan will push more cold air than hot air over a given period of time -- not that there is some magical fan with a built in cooler.
 

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As long as you are looking for ideas for hushboxes -

make sure filters are in your plan.


Since you are going to be dragging a lot of air past

and through your projector for cooling - keep in mind

that the projector is an optical device - and the

immediate vicinity should be as clean as possible.


Ambient air contains suspended contaminants that will

build up in your projector and hushbox. Just look at

the vents and ducting of your house's heating and cooling

system.


You might want to make provisions in your hushbox to

accept HEPA filter cartridges or the electrostatically

charged furnace air filters. See what your local hardware

store has in stock.


Dr. Gregory Greenman

Physicist
 

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Thank you for your comments and ideas.

I'm still concerned about the inlet ports, in the manual,

it does not show an inlet on the opposite side of the projector; so pulling air from the outlet side would also pull air away from the inlet on that same side and may result in less air inside the pj??

I was hoping to fit the lt150 in a hushbox in a wide arm on my sectional, but I don't think that will work, due to the small size it would require. If someone comes up with a very small hushbox that handles the heat well, I could sure use the design.

Thanks again.


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Jim Story

Live long and Prosper
 

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Quote:
Originally posted by Jim Story:
in the manual,

it does not show an inlet on the opposite side of the projector; so pulling air from the outlet side would also pull air away from the inlet on that same side and may result in less air inside the pj??
It doesn't? Look at pages E-8 and E-9 -- I'm referring to the inlet mentioned in the drawing on page E-8. I do share your concern with the inlet adjacent to the exhaust port.


"Thumper" has disassembled a LT150 and commented on the cooling design. See: http://www.avsforum.com/ubb/Forum10/HTML/008011.html


If size is a strong consideration, perhaps you could use a box with a detached, hose connected blower/fan hiding behind the couch? How much room do you have in this arm?

 

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Time for an eye checkup!

I totally missed that inlet on pg E8,

thanks for letting me know.

I thought about some kind of attachment,

I may try that experiment one of these days,

but for now, I'm gonna just use the pj at my feet;

the screen will be smaller (72" wide vs 96").

The upside is, I can stay with my present screen

for now.

Thanks again.


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Jim Story

Live long and Prosper
 
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