Originally Posted by Rhizzlebop
Looking at the panasonic inline fans, looks that's gonna cost me about $200 for the fan. I had planned to drop a 4" duct to the hush box area, but this is making me wonder if I should try to squeeze 6" over there. Some comments were saying the fans were quiet but when you connect 4" duct, the fan gets loud. If I run the duct and go with the inline, then the 4" duct will require I run it about 10 ft.
6" will get you a quiet experience. You will hear noise from the PJ vent off the 4". It won't be loud, but you'll hear it.
Also, if I'm gonna have this expense, I'm now wondering if I should get one large inline fan, and wye off with a 4x4x4 splitter, and connect both the duct to the projector, and the one I previously ran to where the rack is.
Do you mean run 2x 4" flex ducts from PJ hush box to the fan? Can you do two wye's? A 6x4x4 and a 6x6x6? If you can, I would do that. Run 2x 4" flex ducts from PJ hush box to the 6x4x4. Plug the 6 side into your 6x6x6. Plug the other 6's sides of the 6x6x6 into your in-line fan and your 6" from the A/V rack. You will get a bit more pull from the A/V rack, but only because it's closer to the fan. You will get sufficient pull from the hush box.
Another idea would be restrict the pull from the A/V rack, but if you do that you'll increase the velocity (and noise). You'll still pull stronger from it due to proximity to the fan. It would increase flow from PJ hush box, but at expense of noise at A/V rack. If the rack is fully closed up, should be non-issue.
That fan is very quiet. You won't hear it. You will hear some air / wind noise.
Your best bet is a fan that you can control the speed via either onboard controller or a potentiometer (make sure to use one rated for motors).
The next animal is, that my room doesn't have dedicated cooling, and I really don't want to go tapping directly into my AC ductwork. If I dump the heat in my AC closet, I guess it'll slowly just get hotter in there, and eventually push heat out under the door.
I guess as long as the space above the ceiling keeps pulling in ambient air to the hush box, that'll be fine if my AC closet gets warm. This closet is in the basement, so its NOTHING like what an airhandler would see in an attic (like my upstairs unit is).
However, this does give pause to my idea of putting my LED transformers in the AC closet. If I purposely blow heat INTO that closet, it'll specifically make those transformers run hotter in there. That means I now have to figure out somewhere else to put those things.
Between equipment, body heat, and PJ, your room is likely to get hot without HVAC of some sort. A few members who live in cooler climates and don't have HVAC in their room have reported no issues, but much depends on your usage of the room.
Originally Posted by Rhizzlebop
That's an excellent fan.
Makes me wish I had run a 6" to the rack. Thats about 15 ft of 4" flex stretched tight and straight.
If I run 6" to the projector, then i'll pretty much only pull air from the projector and not the rack, so I think a 6x4x4 splitter is the only option.
That's a reasonable plan.
I can hang this thing on a couple iso clips, and wrap it in some dynamat, and if its inside my AC closet, it'll probably be quiet enough. Hopefully a lot of noise wont come down the thin uninsulated duct and reach the room.
Yep. That's going to be your Achilles Heel I'm afraid. The 4" flex duct that is.
So, let me explain my experience with return duct, airflow, and noise. In my build I have the following slightly convoluted setup for my return ducts:
Main grille 16x16 with dual 6" round flex duct
A/V Rack grille 6" round flex duct
Soffit mounted PJ grille 4" round flex duct
My main grille has dual 6" round flex ducts that route to a muffler, which dumps the air into an 8" round flex duct. That runs to my attic, where it feeds into a 8x8x10 "wye." From there it travels along a 10" flex duct for a few feet, then steps down to a 9" flex duct (the original room duct), and from there goes to a 2 cu ft plenum, and from there to a 12" flex duct that leads to the main return plenum.
Meanwhile, the other 8" port on the wye is fed from another wye that is an 8x6x6. The two 6" branches come from the A/V rack and the PJ vent. The PJ vent steps up from 4" to 6" before connecting to the 8/6/6 wye.
The PJ vent uses a 4" flex duct. The A/V rack uses a 6" flex duct.
Now... the part you're waiting for... noise.
I hear NOTHING from my main grille. Absolutely silent. The only reason I know it's working is if I place a piece of paper near it, and it gets sucked up and stuck to the grille. The A/V rack 6", I can hear it only if I'm very close (within 2') and right now there's no equipment in there so I expect it to be silent once the rack is full. The 4" PJ vent in the soffit is a bit of a sore point.
I have an in-line duct fan in the return apparatus. It is an 8" fan, about 8-10' from the step-down to the 9" duct in the attic. Pros and cons of using this fan:
- My ductwork works a bit too well in terms of reducing velocity of the air; when HT room is in use, I really need the in-line fans on or the room gets too warm quickly
- Return fan only adds some additional noise, but only bothers me relative to the 4" flex duct from PJ
- I don't hear the fan itself in the HT room. Noise described above is wind noise.
- I do hear increased noise in the form of wind velocity from the A/V vent and the PJ vent when the fan is on
- Noise from the A/V rack vent (6" flex duct) is still only noticeable up close; I just notice it's stronger/slightly more wind noise when fan on
- Fan on makes noise from 4" PJ vent much more noticeable vs with fan off
When there's any ambient noise in the room (talking, movie, music), I don't hear the PJ vent. It's only when the room is silent. No one else has noticed it. Just me. Go figure.