Fairly whooshy vent return problem

[Poodle Head Mikey]

It does seems impossible as described and as I understand the issue.

On one hand we have excessive noise. Which typically results from a lot of air flow.

On the other hand we have the description that air is flowing Out of the return duct.

I am just having a problem reconciling that both things are happening simultaneously. <g>

And let's go back to wht I said originally - let's make sure that you do, in fact; have the correct air flow to start with.

Then, if you do, we can start on how to first minimize the noise, and then to break the sound-path of the noise, if neccessary.

PHM
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QUOTE=caslon;1925488]First of all, I know it sounds wierd, but I am guessing you CAN have an uptake of air at the return and at the same time some kind of backpressure or whatever where you can feel air being driven back down into that return cavity and out of the grill. We can go no further if you think this is an absolute impossibilty.

Second of all, I am a painting contractor, not an HVAC contractor, so I may have jumped ahead as to what is causing it or the mechanics of it all. Sorry.

It's almost as if there IS air being correctly sucked in, but at the same time, so much so that some is actually being forced back down into that same return area.

Trust me when I say I can feel air being expelled from the return intake grate.
That air rises up to the thermostat directly across from the intake grate and affects the current reading temp of the thermostat.

At least read back my entire post, all of you. Someone reads my latest post and tells me to get a bigger intake grill, then repeats the same suggestion.

Any and all info you want me to provide, I will. Read back to the beginning and at least check out my freaking pics.[/QUOTE]

[caslon]

Poodlehead, that's exactly what I am calling them back for. I'm not sure I do have the correct air flow. They installed it and left...it's only later that I noticed this airflow problem.

That is...an inordinate amount of airflow felt coming out of the return vent just below the AC/Heater closet.

Maybe it's just normal airflow uptake that is causing what I feel as air coming out of my return vent.
Seeing as its such a large cavity return area, but I swear I feel air forcing back down.

Something needs tweaking a little. I've never held my hand over a return vent and felt air coming out.
I have no doubt that if you were here on the scene, you could size it up immediately.

[Poodle Head Mikey]

But how about this -

Can you make a piece of paper move Away from the return by holding it where you feel the air coming out?

I ask because sometimes it does feel like air is flowing out - when it is flowing in. You feel the air on the back of your hand and mis-interpret what is actually happening.

And I'm just trying to help here - let's just walk this thing through. <g>

[caslon]

I'll try it now. Thanks.

There WAS uptake of a paper inside the cavity at the filter, I did that.
(at the same time there was air seemingly forced down so much that small
debris was blowing around inside the cavity. I may be wrong, but I think it was
downward air somehow causing that light debris to move around.

Anyways...will test it now.

[caslon]

Actually..the paper DOES stick to the grill vent. WOW.

Why did it feel as if there was downward pressure of air coming into that
large return vent cavity area with the AC/Heater just above?

Is that the reason? The close proximity of the two?

I'm still getting higher than expected thermostat readings in my hallway.
That's probably due to lots of warm air collecting there? My kitchen and
fridge and all my living room pc's heat making for a hallway higher than normal reading?

Having a small condo with an AC closet and a large return right below it probably threw me off?

Thanks dude. I still have some small leaks they need to take care of.

I also have another question about putting in a larger register in my living area. I'll save that for a seperate post and pics to show what I mean.

Part of what solved this (maybe) was my putting a USPS box at the front of the cavity filter intake.
I will post later what I mean. After I did that...lots less "feeling of air being forced out."

Thanks again. Hang on...pic coming up about my USPS box temp fix.

EDIT:

Try and check out my earlier pic of the return "cavity."
I put in a rug and just this "experimental quick attempt"
You'd be surprised how much it reduced the sound "whoosh" and the feeling of air coming out of the vent. It's just a temp experiment fix..but wow...drastic improvement.
I stuck a USPS box at the front and one other box at the left to break up the movement of air.
Huge difference!

[TrueAirBC]

Because the cavity is so large what you are likely feeling is such of a rolling effect. The air is "whoshing" around in that cavity.
The air is being pulled up so strongly becasue it has no where else to draw from, if it were directly ducted to the grill it would likely pull in any small pets you have. lol
Is there any way you could put anyother return air on the opposite side of the wall that the grill is on?
I did read your post front to back and looked at your pics prior to my statements.
My response about the grill size is only becasue I have seen this before more than once. Your furnace is starving for air and likely has a higher than normal temperature rise. Also I am not saying to get a larger grill only one that has more space in between the blades (free area for the air to travel through).

[caslon]

I may get a bar grill..ok. I think it was just a matter of the whole setup being right above the return area. Putting in my simple temp baffle and rug made a huge difference.

[dash]

Your baffle looks like it way be too restrictive for proper air flow,or raise the static too much.

Using vanes and coming out from them to the grille will eliminate turbulence.

What ever you do,seal off those wall cavities in the return box ,as they are likely drawing air from places outside the envelope.