Therwen Backdraft Damper 8-Inch Manual Duct Damper for Air Balancing | Galvanized Steel

Therwen 8-Inch Backdraft Damper for Air Balancing

Therwen's Backdraft Damper delivers reliable, manual control for ducted airflow across multiple branches. This 8-inch damper is built with a galvanized iron sleeve for durability and is designed to be inserted into standard ventilation runs, helping you balance airflow where it's most needed. The bend end interface measures about 7-7/8 inches (20 cm) in diameter on one side, while the opposite end is about 8 inches (20.32 cm) wide and the unit stands roughly 6 inches (15.24 cm) tall. This geometry supports straightforward retrofits in many homes and commercial spaces, including range hoods, fans, and other HVAC branches.

Easy to install: simply slide the damper into the pipe, align it with the chosen position, and screw it in. Sealing all joints with pipe sealant can minimize air leaks and help improve overall HVAC efficiency. The design is not intended as a complete air termination device; instead, it enables practical balancing by letting you redirect portions of the flow to specific locations.

Durable construction meets demand: the 8-inch damper is wrapped in a galvanized iron sleeve, offering high hardness and temperature resistance. This helps resist deformation and moisture, supporting longer service life even in challenging environments. The damper is compatible with a wide range of applications, including air conditioning, dryer vents, exhausts, range hoods, heating systems, and other residential, commercial, or light industrial HVAC setups.

Key benefits and typical uses

• Manual adjustment allows on-demand airflow control without complex controls
• Simple installation with basic tools and quick positioning
• Galvanized iron sleeve provides durable, moisture-resistant housing
• Not a sealed termination device; useful for achieving balanced airflow across branches
• Fits 8-inch ventilation ducts and compatible with most standard systems

Practical tips for installation and maintenance

• Slide the damper into the pipe, screw it to the desired position, and seal the seam with tape
• Seal all connections with pipe sealant to reduce leaks and improve efficiency
• Check seals periodically and re-seal as needed to maintain performance

In real-world setups, the damper offers flexibility to balance airflow between rooms or appliances without extensive ductwork changes. If you plan multiple dampers, install each on its own branch to fine-tune the overall system performance.