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Dealing with HVAC vent air flow noise?

We've just replaced our split HVAC system with upgraded capacity and higher quality/efficiency components. One aspect of the upgrade is a 1/2 ton higher capacity air handler with a multiple speed blower. While the system is much quieter overall than the previous one, during the heat of the day when the air flow is ramped up to it's greatest arflow, I notice more air noise than before coming from the vents. It seems that if a larger outlet or an additional outlet were installed, resulting lower air volume/friction/turbulence would reduce noise in the listening area. Have any of you dealt with a similar problem? What worked for you?
photon46
photon46 OP
1,008 posts
 
We're going to have the contractor start by making adjustments to the blower speed programming. While researching the issue, I found www.softairediffusers.com offers airflow diffusers that look to be of interest to anyone looking to tame noisy vents. They have engineering specs listed that show how effectively they reduce vent noise at a given cfm airflow.
essentialaudio
1,147 posts
 
Reducing the fan speed can help when the full capacity isn't needed, but the full airflow should be provided when the full capacity is needed and as such won't reduce the noise.
photon46 OP
1,008 posts
 
Essentialaudio, that's right. The blower is 17 speeds & programable with two differential stages. The plan is to reduce the blower speeds in the first differential stage when there's a 1 degrees variance from the programmed thermostat setting. When the second stage differential of 2 degrees variance happens, then the higher blower speeds will come into play.
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