Your Acoustic First Aid Kit

We’ve all had the call that something is too loud.  The VAV box, the diffuser, the grille.

Before you start looking at anything, consider if a flex change can be effective.

Below are the performance tables for type 1 and type 6 flex by Flexmaster USA.  These products are more expensive than cheapie flex, but they do perform.

Don’t get me wrong, duct silencers are critical to design.  But if you don’t have them, the right flex will equal silencer performance and bail you out of a jam.

Type 1 is high quality standard flex.

Here’s the selection for type 6, the acoustic type

Data table side by side, using 8” round, 6’ length

Some of the data is surprising.  For example, if you extend the flex from 3’ to 6’, some of the insertion losses double or triple.

Remember, the frequency is matched to a wavelength.  The shorter the wavelength, the greater number of times the wave interacts with the flex.

On one hand, too much flex is a problem with pressure drop.  Especially if the flex isn’t properly supported.

On the other hand, 3 feet of flex might not cut it.

Got an acoustic issue that needs solving? Give us a call. (414) 351-1999.