Using Flex on Branch Runs?

[banzaitoyota]

The latest estimate I have received has 5' of flex on each rigid branch for noise isolation. I realize this is cheap and quick, but isn't using a flexible duct connector system such as insulflex (http://www.durodyne.com/xephr/list/DUCT_CONNECTOR) a better insulation method?

[beenthere]

No.

Flex duct can have a rating of R4.2(same as the connetor you linked to) to R8, and I believe special ordered, it can have a R10 value.

That connector is good for isolation of vibration.

But thats not going to help prevent air noise.

The flex duct will minimize both air noise, and prevent duct vibration noise at the registers.

The flex connector you linked to can only prevent vibration noise. And would be a waste of money and time using it for what your contractor is trying to acomplish.

[banzaitoyota]

Thanks for the info. I'm just trying to make sure I get the best system possible for the $$$$$