Does Venting Through Attic Need To Be Insulated

The model building codes allow both vented and unvented roof assemblies.

Does venting through attic need to be insulated.

Otherwise the exhaust duct gets too cold when it runs through the attic. A combination of air sealing and insulating the attic floor while providing ventilation considerably reduces potential for condensation as warm moist air is less likely to enter the space and condense on cold surfaces. The solution properly insulate the vent ducts. In un conditioned space such as an attic where otherwise your fan duct will be exposed to cold attic air in winter use insulated solid metal ducting or insulated flex duct.

To completely cover your attic floor with insulation out to the eaves you need to install rafter vents also called insulation baffles. The choice of venting or not venting is a design and construction choice not a requirement determined by the physics or by the building code. The reason exhaust pipes are insulated in unconditioned spaces your attic is because they carry warm and moist air from your home to outside. If you plan to install insulation on your attic floor then most building codes require that the attic be vented.

Insulate the bathroom exhaust vent fan ducts. For example see section r806 1 of the 2015 international residential code. A cold duct allows condensation of moist indoor air leading to drips from the exhaust fan. Attics or roofs can be designed and constructed to be either vented or unvented in any hygro thermal zone map 1.

All ducts should be insulated and sealed air tight. At first glance it can seem counter intuitive. Make sure the air handler giant rectangular fan unit for the ac is sealed. Complete coverage of the attic floor along with sealing air leaks will ensure you get the best performance from your insulation.

To completely cover your attic floor with insulation out to the eaves you need to install rafter vents also called insulation baffles. If this pipe is not insulated the heat carried in the air transferred to the pipe will cause condensation and potentially cause water damage at your ceiling or in your attic. Inspect the hvac system and ducts in the attic. In no case should bath fans blow air directly into the attic.