Exhaust Fans

[Bryce_H]

Hola All,
Well I'm am finishing my basement into a dedicated home theater and want to install 2 exhaust fans. One for my projector hush box and one for my component cabinet. I know what I want to do, just not exactly how to do it or where to buy the parts

Hush Box: I will have an air intake in the projector hush box, run flexible vent tubing (with several bend to decrease noise transmission) to an exhaust port in another room. The exhaust port end will have the fan on it. I would like the fan hard wired but triggered by my Sony VPL-400Q 5v DC control (why sony picked 5v instead of 12v - who knows!!). Not a current concern, but will replace with a 12v trigger when I get a new projector.

Component cabinet: similar setup to above, but will be powered and triggered by the switched outlet on my receiver (Yamaha DSP-A3090)

So where can I buy the fans?. Looking for good CFM (>50) and low noise. I first thought about computer fans, but they all run off 12v. I checked the bathroom fans at Home Depot and Lowes, but they all seems overkill for what I need - plus their loud (unless you drop some cash), and the fans is at the intake end.

Basic question: Where can I buy 120v (household current) fans - preferrable at a resonable cost.

Thanks.

 

[Swerd]

Where can I buy 120v (household current) fans - preferrable at a resonable cost.

Parts Express has 115 volt AC fans, 100 CFM, for $13-16 each.
http://www.partsexpress.com/webpage.cfm?DID=7&WebPage_ID=3&Start=2&ObjectGroup_ID=231&sm=1&so=2&search_type=70477056&desc=ASC

 

[Bryce_H]

Sweet thanks - any idea how to hook it up to a trigger??

 

[JohnA]

Sweet thanks - any idea how to hook it up to a trigger??

Is the trigger a stanard AC plug, like the ones on the back of your receiver?

If so try these:

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=250-050

and then add a plug end.

I hope that helps

 

[Bryce_H]

No, the trigger is a like a mini-headphone jack that sends an impulse signal to something to turn it on or off. For example: you turn your projector on and it send a signal to a mechanism to open the curtains over your screen. As opposed to actually providing the power for the curtains. It's like a switch.

I am already thinking that the extended plug might be the best option.

Thanks.

 

[HookedOnSound]

Hush Box: I will have an air intake in the projector hush box, run flexible vent tubing (with several bend to decrease noise transmission) to an exhaust port in another room. The exhaust port end will have the fan on it.

I could be wrong here but I think it's actually harder on the motor to pull than to push. I think you might have to put your fan in the hush box (put a larger fan/vanes but with lower RPM to reduce noise).

You might have to experiment, at the very least make sure you to use a thermometer (like the ones for a fridge are pretty accurate and cheap$) and check you temp. while testing....

Good Luck

 

[mustang_steve]

Intake/exhaust doesnt matter as much, the fan will still see a static load on one side of the fan, and with axial fans, static load will bog it down regardless of whether it's in front or back.

Just place it where you will, or if your really worried about it, get two fans each and run a multi-ducted air in/out setup for each. That way you get zero noise from the air intake or exhaust.

 

[BMXTRIX]

Mustand Steve is dead on. You definitely want air intake and output to be outside the theater so the projector is completely isolated. Fans inside projectors these days typically are much quieter than the one inside your PC because of how noisy they used to be.

With that in mind, whatever outboard fan you use will likely be far louder than the one inside your projector already. It makes a lot of sense to keep any air intake or output vents in another room.

You basically need a low voltage triggerable 120v switch. I'm pretty sure you can find those on parts expresss. I know I have seen them around, but haven't looked. There are also some of the better Monster Power centers that have 12v input triggers on them to trigger some of the 120v outputs. I believe the 3600 has it.

 

[Bryce_H]

I'll look around part express for the triggers. Also appreciate the feedback about the where to locate the fan. The plan had always been to put them outside the theater.

In term of the power center, I just bought a Pananmax 5510 (I'm not a fan of Monster, mostly because of their business practices)

 

[BMXTRIX]

That's a pretty surge protector. I just worked at a place that sold Monster for incredible markup but also knew the product had 12 volt triggerable outputs that could be assigned to specific outlets.

Surgex also has some similar surge supressors that allow that.

I know there are some 12v triggerable switches fairly inexpensive available though. Just not sure where.

 

[Bryce_H]

Well, I got everything installed and here is what I ended up with

1 dedicated 4 inch intake duct (~15 feet long) to the hush box (no fan) from the rec room

1 dedicated 7 inch exhaust duct (~20 feet long) with an 8 inch duct booster (500cfm) at the far end (away from the future hush box)

The duct booster will be on a light switch dimmer with power provided from the switched outlets on my reciever or panamax. this will allow my to control the volume of air and have it only running while using the projector.

The hush box will be completely enclosed with complete air exchanges from the rec room. This will help isolate the sound of the air exchanges and the projector fan noise.

The hush box (not built yet) will be lined with acoustic carpet (from parts express).

If I find the projector is overheating I will redesign the hush box to have an air intake in one of the sides - this way it will be pulling air from the rec room and the HT room.


What do people think??

 

[FredT300B]

Try Ebay

Do an Ebay search under consumer electronics / cooling fans. You will see many options like this one, which worked nicely for me. It's a 12 volt fan powered by a 5V wall wart so it runs slower and quieter. They're very affordable and someone else has done all the work of matching the power supply to the fan.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=71550&item=5768322992&rd=1