{"product_id":"systemair-411114-backdraft-damper-6-inch-circular-duct","title":"Systemair 411114 Backdraft Damper 6 Inch Circular Duct","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe SYSTEMAIR 411114 is a 6-inch backdraft damper designed for circular duct systems in mechanical ventilation applications. It prevents reverse airflow when the fan or air handler is not running, protecting system performance and indoor air quality. The damper mounts inline within round ductwork and operates passively — gravity or differential pressure opens and closes the blades without any external power or controls. HVAC technicians and sheet metal contractors typically specify this component in exhaust, supply, and makeup-air systems where backflow prevention is required.\u003c\/p\u003e\n\u003cp\u003eThis damper is suited for residential and light commercial ventilation systems using 6-inch round duct. Common install scenarios include bathroom exhaust fans, kitchen range hoods, ERV and HRV ducting, and inline fan discharge points. The single-piece construction simplifies installation in new construction and retrofit applications alike.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e6-inch diameter fits standard circular ductwork\u003c\/li\u003e\n  \u003cli\u003ePassive operation — no motor, actuator, or low-voltage wiring required\u003c\/li\u003e\n  \u003cli\u003ePrevents reverse airflow when ventilation equipment is off\u003c\/li\u003e\n  \u003cli\u003eDomestic manufacture — country of origin: USA\u003c\/li\u003e\n  \u003cli\u003eLightweight at 1 pound for easy single-tech handling\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style replacement or new-installation backdraft damper for 6-inch round circular duct systems in residential and light commercial ventilation applications.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is typically performed by a licensed HVAC technician or sheet metal contractor. Power down all connected fans and air-handling equipment before installing or replacing the damper. Secure the damper in the duct run using sheet metal screws and foil-backed tape per SMACNA duct construction standards. Verify that airflow direction arrows, if present on the damper body, align with the intended supply or exhaust direction before fastening.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDuct Diameter\u003c\/strong\u003e: 6 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDuct Type\u003c\/strong\u003e: Circular\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProduct Height\u003c\/strong\u003e: 5.984 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProduct Width\u003c\/strong\u003e: 7.007 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 1 pound\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCountry of Origin\u003c\/strong\u003e: USA\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUPC\u003c\/strong\u003e: 65073769060\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: SYSTEMAIR\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 411114\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SYSTEMAIR","offers":[{"title":"Default Title","offer_id":51383667753266,"sku":"411114","price":47.19,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/312670694.jpg?v=1782603774","url":"https:\/\/voomisupply.com\/products\/systemair-411114-backdraft-damper-6-inch-circular-duct","provider":"Voomi Supply","version":"1.0","type":"link"}