Lennox X4257 Zone Damper, Rectangular Bottom Mount, 8 Inch x 20 Inch, 6817L

The Lennox X4257 is a factory-engineered rectangular zone damper designed to optimize airflow control in residential and light commercial HVAC zoning systems. Featuring an 8 inch by 20 inch opening and bottom-mount design, this damper helps balance temperature across multiple zones, improving comfort and system efficiency.

Manufactured to Lennox specifications, the X4257 ensures a secure fit, smooth operation, and reliable sealing performance when integrated into compatible zoning equipment. It is commonly used in retrofit and new-construction ducting applications where precise air distribution is required.

Key Features:
• Rectangular 8 x 20 inch configuration for controlled airflow management
• Bottom-mount design for simplified installation in tight duct runs
• Lennox part X4257, reference 6817L
• Compatible with Lennox zoning systems and select forced-air HVAC setups
• Helps reduce hot and cold spots and enhances thermostat accuracy
• Durable construction for long-term performance

Applications:
• Multi-zone residential HVAC systems
• Light commercial air distribution
• Retrofit duct installations
• Variable airflow temperature control

Specifications:
• Part number: X4257
• Reference number: 6817L
• Style: Rectangular zone damper
• Mounting type: Bottom mount
• Size: 8 inch x 20 inch