Insulating exhaust fan vent pipes

[JesseWBryant]

Is there a code to support the need to insulate bathroom exhaust fan vent pipes to prevent condensation inside, or is this simply a regional suggestion?

[Brandon Chew]

From my copy of the 2000 IRC. Italics are mine.

§N1103.3 Duct insulation. All portions of the air distribution system shall be installed in accordance with §M1601 and be insulated to an installed R-5 when system components are located within the building but outside of conditioned space, and R-8 when located outside of the building. When located within a building envelope assembly, at least R-8 shall be applied between the duct and that portion of the assembly furthest from conditioned space.

EXCEPTIONS:

1. Exhaust air ducts and portions of the air distribution system within appliances or equipment.

2. Ducts within the building envelope located in detached one- and two-family dwellings or townhouses.

[Bill Kibbel]

Originally posted by JesseWBryant

Is there a code to support the need to insulate bathroom exhaust fan vent pipes to prevent condensation...?

So, If you don't keep your farts warm they generate condensation?

Sorry, I'm not being helpful. [:-dunce]

I would think that it would be required on dryer vents before bath exhaust vents.