Sound proofing HVAC return duct

[General Lee]

I'm about to have a sound proofing liner installed in my HVAC return duct. My return is a little undersized and I simply cannot take the air noise any longer. The return is above my recliner and I'm limited in options of where I can relocate it.

I'm having the same return duct enlarged in the basement because it's exposed but in side the drywalled chase will remain the same with the exception of enlarging the opening behind the grill. HVAC tech is also going to line the new duct with a HVAC sound proofing liner and the duct in the chase as far he can reach. This is my cheapest and easiest option to make an improvement.

Anyone know anything about the this "liner"? Does it help with air noise? There is no buckle sound just loud inrush of air.

 

[KTurner]

My return is a little undersized and I simply cannot take the air noise any longer.

We had our heat pump and ductwork replaced last year. One of the installers mentioned that if the noise at the return duct was too loud, I could bend the fins of the return grill (which I have NOT done as the noise isn't bad). It seems like it'd be easy to see if this might help by opening the grill while it was running.

Keith

 

[General Lee]

I have heard of that option sometimes working but its not gonna help mine. I have a 3.5 ton unit and only have ONE return that is 14x16 even though the grill and filter is 20x20. That is simply to small for that tonnage and my fan is huge, its pulls a lot of air.

 

[dex3361]

You might try a different speed on the fan. I had to reduce the speed because of noise. It is usually a wire swap in the fan housing. mine has 3 different speeds.

 

[radioman]

I think I have one of those liners . Its just a plastic/vinyl connector to connect ducts but what it does is eliminate the vibration from furnace fan from continuing between metal connectors. Can post a pic if you want. As for changing speeds, it can help, but you need to know if your fan is capable of it. My old furnace wasnt, and my new one is.

 

[General Lee]

This liner goes inside the duct and is for acoustic purposes no insulating effect. I've seen the rubber boot connectors, I actually have one on one section of the duct. This liner is supposed to dampen the continuous "whoosh" sound as apparently even though its only air rushing through, the duct amplifies the sound. I've also tried different fan speeds, LOW/MED and MED/HIGH, only 2 speeds and there isn't much difference between the two.

I'm tired of having to keep turning up the volume to the TV when air is on and turning it down when its stops. I've researched the liner a bit and from what I've read it helps. HVAC tech says it will definitely help, but how much to your liking won't be determined until its installed. So in short we are enlarging what we can and can get to before tearing holes in walls or cutting holes in the floor and ceiling for a new located return.

 

[hosspuller]

The noise is related to the air velocity. Insulation on the inside of the duct may help but the reduced duct size will increase the noise. Don't try to change the volume of air. That will decrease the cooling. Look at installing another return duct to the unit. You didn't mention the outlets, but the same applies. More ducts = reduced air velocity = less noise.

 

[s219]

Yeah, can you put another return elsewhere in the house?

 

[Ed of all trades]

Was HVAC install foreman for a couple of years. Don't see how a liner is going to help, most of the air noise is at the intake not down in the duct. I would tear out the drywall and do it right or I would learn to live with the sound. I think the liner is a waste of time and money, your money.

 

[kenmac]

I don't know how thick this noise reducing fabric is but, It may reduce the size of the return even more. I wouldn't change the fan speed with out having someone check your unit . You could flood your comperssor with refrigerant /change your SH/SC #'s Your #'s may be off now with the return being small