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AVS — Type BW Attic Shield

How to Specify

Using tables from the National Fuel Gas Code or our Sizing & Application Guide, determine the diameter of venting required. The Sizing & Application Guide also offers tips on good design including multi-appliance system sizing and design. The System Design and Installation Guide is an additional resource.

Amerivent FAQs

AVS — Type BW Attic Shield

Assets/Details

Installation Instructions (1 MB, PDF)

Required by Los Angeles Code and UMC

The Type BW attic shield is used on a single-story building or on the top story of a multi-story building for Type BW gas vent. A 26-gauge galvanized sleeve should extend from the top of the ceiling plate into the attic. A Type BW attic shield is required by Los Angeles Code and UMC.