Fantech FIDT Flexible Insulated Duct

Flexible, insulated duct is the preferred duct for bathoom exhaust systems.  It has almost no leakage, and the insulation helps minimize condensation.  In addition the noise attenuating properties of this duct help inline and remote exhaust fans achieve such low sound levels in the bathroom.

This duct is also used for general air distribution. However, it is NOT suitable for kitchen exhaust.

model description usually ships price QTY
FIDT 4 Insulated Flexible Duct. 4" Round Duct. UL Listed. 25 Foot Length. 1 Day. In-stock $49.90
FIDT 5 Insulated Flexible Duct. 5" Round Duct. UL Listed. 25 Foot Length. 1 Day. In-stock $55.60
FIDT 6 Insulated Flexible Duct. 6" Round Duct. UL Listed. 25 Foot Length. 1 Day. In-stock $59.30
FIDT 8 Insulated Flexible Duct. 8" Round Duct. UL Listed. 25 Foot Length. 1 Day. In-stock $64.80
FIDT 10 Insulated Flexible Duct. 10" Round Duct. UL Listed. 25 Foot Length. 1 Day. In-stock $85.90
FIDT 12 Insulated Flexible Duct. 12" Round Duct. UL Listed. 25 Foot Length. 1 Day. In-stock $96.00
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Stocked in both Oregon and New York state. See transit maps below.

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Do you have questions about the products on this page?

Click on the ? image on the left or this link to ask us your questions!
#1 Q:   Is this good to ideal for HRV supply and extract ducting? I realize it likely depends on routing/turns, but is technical information available giving pressure drop per length, per ID at various flow rates?
A:   Yes, this duct is great for HRV/ERV ducting. This manufacturer does not publish pressure drop specs but in general you can expect flexible duct to give you twice the pressure drop per length compared to smooth rigid duct.

       Asked on 2023-11-06 by CB
#2 Q:   Would traditional rigid ducting w/ insulation wrap be much better than this flexible duct in terms of flow and sound?
A:   Rigid duct will be better in terms of flow since its smooth. It will be much, much worse in terms of sound. Flexible insulated duct is very effective as a sound attenuator, unlike rigid duct which just transports the sound.

       Asked on 2019-07-05 by NT
#3 Q:   What is the outer diameter of the 4 and 5 ducts?
A:   Its about an inch of insulation all around so 4 inch duct is 6 inches outer diameter, and so on.

       Asked on 2018-09-13 by Carl
#4 Q:   Is the interior smooth or ribbed?
A:   The interior is ribbed as is all flexible insulated duct like this. The ribbing comes from the wire coil required to keep the duct from collapsing.

       Asked on 2017-04-24 by ROb
A:   It is, as it keeps noise to a minimum as well as keeps the heat or cool you just recaptured in...The R value is 4.2.

       Asked on 2013-12-17 by ERIC
#6 Q:   Is the fan tech fidt insulated flex duct suitable for bathroom exhaust? My contractor said it will hold the condensation.
A:   It is used for baths quite a lot. There is a poly liner to keep the moisture from the insulation, and we do recommend running the fan for a few extra minutes to ensure the duct is dried.

       Asked on 2013-07-02 by Rich

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