Does Venting Through Attic Need To Be Insulated

Inspect the hvac system and ducts in the attic.

Does venting through attic need to be insulated.

The reason exhaust pipes are insulated in unconditioned spaces your attic is because they carry warm and moist air from your home to outside. To completely cover your attic floor with insulation out to the eaves you need to install rafter vents also called insulation baffles. You insulate your home to reduce temperature fluctuations and save on utility bills but then you allow fresh air to flow through the attic no matter. A cold duct allows condensation of moist indoor air leading to drips from the exhaust fan.

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. Insulate the bathroom exhaust vent fan ducts. 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. At first glance it can seem counter intuitive.

To completely cover your attic floor with insulation out to the eaves you need to install rafter vents also called insulation baffles. Otherwise the exhaust duct gets too cold when it runs through the attic. Attics or roofs can be designed and constructed to be either vented or unvented in any hygro thermal zone map 1. In no case should bath fans blow air directly into the attic.

The model building codes allow both vented and unvented roof assemblies. 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. Does bathroom vent piping need to be insulated.

The solution properly insulate the vent ducts. For example see section r806 1 of the 2015 international residential code. 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. All ducts should be insulated and sealed air tight.