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Discussion Starter · #1 · (Edited)
Hey guys,

I'm in the process of designing a basement HT (non dedicated) - and one big problem I don't want to have to deal with is projector noise. That's a problem because I want a large screen and that means a bright, noisy, hot projector. I believe I've eliminated most other noises within the design, through things like housing all the amps / receivers / equipment in an adjacent room.

I've got the opportunity to re-route or redesign the placement and routing of (currently) 3 fancoils and ducting, or to add an additional unit if needed.

For the sake of argument, if I took say a Z1 projector, does it make sense to mount it within the soffits behind some high quality glass, completely isolated from the room, and then have an inlet / outlet for a single dedicated fancoil (housed in a different room) keeping it nice and cool? What kind of cooling power would be needed for something like that?

If that doesn't make sense, what does? Could/should I just add a vent from existing ducting which runs past the projector location anyway? Or is it a bad idea in general to associate air conditioning with projectors?

Any advice or thoughts much appreciated!
 

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I asked about this in the dedicated theater forum and was basically told that my only good options were to build a conventional hush box or get used to the fan noise.

It turns out I have mostly gotten used to the fan noise though I haven't ruled out taking additional cooling/quieting measures in the future. I've seen a few old posts where people dropped the exhaust temps on their projectors substantially by just putting a couple PC fans on the ceiling to move the air around behind the projector so that the warm air doesn't pool there.

I see no problem with having your projector in an enclosure with dedicated cooling. I think the biggest risks are introducing moisture or excess dust.
 

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Keeping the projector in a space isolated from the viewing room will definitely make it inaudible. Even if you don't use a glass and have just a hole for the lens, it will very likely be inaudible from the viewing room. The inner surfaces of the soffit may need to be covered in a soft material to prevent reverberation, and it's important that you leave the recommended space around the projector (see the manual) and that you keep the air flowing. A small fan should be enough to keep the air moving, and many people regulate the air conditioner in their theaters to keep ambient temperature adequate for the projector, but as the poster above mentioned it may not be a good idea to have a duct from the air conditioning system releasing air with potential particles and moisture directly onto the projector.
 

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Discussion Starter · #5 ·
Thanks very much guys.

I'm going to talk to my installation company about their recommendations on how to deal with this. I'm not sure on whether the air conditioning method will introduce any moisture or particles - so first step for me will be to find out more about that.

The approach, with fancoils and ducting - I believe dehumidifies the air - and collects it in a drip dray in the fancoil itself. But I'll check this.

Also great advice to leave sufficient space around - I haven't picked a projector yet and I want to be future proof, so I'll leave a decent space which should accommodate a variety of projectors. I'll also try without glass and see if the noise is audible, before going down that road :)

I'll update this thread when I get a proposal together :)
 

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Are you considering cooling the projector below room temperature?

If so, even if air conditioning removes moisture from the air while it is on, once the projector and air conditioning are turned off, there's a possibility that air around the projector will get replaced with warmer air from elsewhere with higher moisture content, and if its dew point is higher than temperature of projector parts, you would get condensation which could damage the projector.

On the other hand, I wonder if this setup could help prolong lamp life.
 

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Discussion Starter · #8 ·
Are you considering cooling the projector below room temperature?

If so, even if air conditioning removes moisture from the air while it is on, once the projector and air conditioning are turned off, there's a possibility that air around the projector will get replaced with warmer air from elsewhere with higher moisture content, and if its dew point is higher than temperature of projector parts, you would get condensation which could damage the projector.

On the other hand, I wonder if this setup could help prolong lamp life.
I'm currently getting advice on this. If I do cool, it'll be to a 'typical' room temperature, rather than aiming to be colder. It'll mainly be to counteract the heat that the projector generates - to maintain room temp.

It might not be necessary, so I'm also looking into an externally mounted fan to just suck the hot air away.
 

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i have the return air duct for our ac system above the projector in the cove at the back of the room where it sits. works fairly well but in the winter, the fan for our AC barely is ever on since our heating system is rarely on (we use a heated floor system). Unless I have a constantly running in-line fan or one that activates when the projector turns on, there won't be enough airflow to seal the cavity.

I have not investigated the possibility of using a piece of glass in front of the projector (assuming constant ventilation). How effective is glass and how much image degradation or refraction would I have?
 

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Discussion Starter · #10 ·
i have the return air duct for our ac system above the projector in the cove at the back of the room where it sits. works fairly well but in the winter, the fan for our AC barely is ever on since our heating system is rarely on (we use a heated floor system). Unless I have a constantly running in-line fan or one that activates when the projector turns on, there won't be enough airflow to seal the cavity.

I have not investigated the possibility of using a piece of glass in front of the projector (assuming constant ventilation). How effective is glass and how much image degradation or refraction would I have?
My understanding is that an Edmund Optics glass panel (3mm) not exactly perpendicular with the projector (off by 7 degrees) basically doesn't visually impact the picture, yet does shield the noise. I think it allows 99.x% of the projector light through if done properly.
 

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My understanding is that an Edmund Optics glass panel (3mm) not exactly perpendicular with the projector (off by 7 degrees) basically doesn't visually impact the picture, yet does shield the noise. I think it allows 99.x% of the projector light through if done properly.
I would much rather just have a hole for the lens and add a rubber band to seal the space between the lens and the hole. I really don't think much audible noise (if any) is going to pass through the lens hole. On the other hand, if the projector exhausts the air from the front, as many do, it will be necessary to push the projector back to leave space on its front (thus having to open a larger hole. But still, I would test the noise without the glass first.
 

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My understanding is that an Edmund Optics glass panel (3mm) not exactly perpendicular with the projector (off by 7 degrees) basically doesn't visually impact the picture, yet does shield the noise. I think it allows 99.x% of the projector light through if done properly.
I have my projector mounted in a hush box using the Edmunds glass. Ideally you want an angle to the glass such that none of the image reflects back into the lens. Also, take advantage of the optical path through the lens to help reduce the tilt angle of the glass. For example, If you have a projector mounted in the top half of the screen such that most of the image is projected downward from the projector, then angle the glass to reflect the image downward below the lens. This will take substantially less angle than trying to aim the reflection above the lens.

The attached images have the port glass at zero degrees, minus 12 degrees and plus 12 degrees. The solid black bar represents the lens and the red area is the reflection off of the port glass (white). I've also enclosed two photos so you can see the angles involved.

Mike

EDIT - Well somehow the photos came out sideways....:mad: FIXED!
 

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Subbed!

I've always wanted a hushbox as pj noise has been an issue since my first and I like the idea of sticking it in a closet. Do you have you other av kit in there, Craig?
 

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I've always wanted a hushbox as pj noise has been an issue since my first and I like the idea of sticking it in a closet. Do you have you other av kit in there, Craig?
I could have put everything in the closet, but it's in a rack where it gets better ventilation.
 

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Hush box building is such a lost art, kinda like anamorphic lenses, that you either have to search the real old posts/threads and get ideas or just build one and pray for the best. I decided to do both. I spent may weeks/months looking at old threads and newer ones from people that have built one recently (not many around).

Also, while at CEDIA this past year, I spent quite a bit of time picking the brains of the tech guy from Draper who was there. They were showing off their hush boxes and he happen to be one of the technical design guys. No way I was spending that much for a hush box so I asked if I could get some pointers for a DIY solution. He was more than happy to give some advice. His take was "keep air moving" to keep it cool. As long as the hot air is being replaced with "not hot" air then you will not have any issues. He said that it is best to use thermal properties to help you. Heat rises so keep the exhaust on the top and try to draw cooler air from the bottom. He said that a dedicated AC is not really needed if your temps in the 70's since the projector would have been in that room, without a hush box, and there would be no issues. As long as the air is moving (in a hush box moving means heat going out as fast as cooler air is being added) you will keep the projector happy.

So my hush box design is just that...keeping the air moving from the back bottom, where the JVC gets its air (with the help of additional fans) and exhausted on top by an inline fan that sucks out just as much hot air as possible. AC Infinity T6 are pretty awesome inline fans that I already torture tested in my server room and it keeps that room quite comfortable (or at least the drives are happy). Two 6-inch ports exhaust hot air through the attic into an outside roof vent. The projector sits towards the bottom of the box with about 18"-24" above it so the hot air rises and stays away from the projector at all times.

I haven't added the port window yet or the rear fan ports since I still have to paint the room and the MDF requires priming before painting.
 

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Let me know if I should put this in a separate thread.

I'm also interested projector cooling.


I will have a gas fireplace in my basement theater room (I like to be cozy in frigid Wisconsin winters when watching a show) . My projector will be very low. It needs to be mounted below a HVAC soffit so I don't have the additional room to build a large hush box.

Does it make sense to install an AC infinity T4 or T6 with flex duct dumping cool air from an unfinished part of my basement right behind the projector so that the intake fans can suck it in? I don't want to overheat the projector.

Can cool air venting help without a hushbox if it exhausts right behind the projector intake?

Thanks
 

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Hush box building is such a lost art, kinda like anamorphic lenses, that you either have to search the real old posts/threads and get ideas or just build one and pray for the best. I decided to do both. I spent may weeks/months looking at old threads and newer ones from people that have built one recently (not many around).

Also, while at CEDIA this past year, I spent quite a bit of time picking the brains of the tech guy from Draper who was there. They were showing off their hush boxes and he happen to be one of the technical design guys. No way I was spending that much for a hush box so I asked if I could get some pointers for a DIY solution. He was more than happy to give some advice. His take was "keep air moving" to keep it cool. As long as the hot air is being replaced with "not hot" air then you will not have any issues. He said that it is best to use thermal properties to help you. Heat rises so keep the exhaust on the top and try to draw cooler air from the bottom. He said that a dedicated AC is not really needed if your temps in the 70's since the projector would have been in that room, without a hush box, and there would be no issues. As long as the air is moving (in a hush box moving means heat going out as fast as cooler air is being added) you will keep the projector happy.

So my hush box design is just that...keeping the air moving from the back bottom, where the JVC gets its air (with the help of additional fans) and exhausted on top by an inline fan that sucks out just as much hot air as possible. AC Infinity T6 are pretty awesome inline fans that I already torture tested in my server room and it keeps that room quite comfortable (or at least the drives are happy). Two 6-inch ports exhaust hot air through the attic into an outside roof vent. The projector sits towards the bottom of the box with about 18"-24" above it so the hot air rises and stays away from the projector at all times.

I haven't added the port window yet or the rear fan ports since I still have to paint the room and the MDF requires priming before painting.
Why add port glass at all ? I find the sound non existent without it.
 
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