{"product_id":"air-flow-products-re043-reducer-increaser-4-to-3-inch","title":"Air Flow Products RE043 Reducer Increaser 4 to 3 Inch","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe AIR FLOW PRODUCTS RE043 is a duct reducer-increaser fitting designed to transition between 4-inch and 3-inch round duct sections in forced-air ventilation and HVAC distribution systems. This type of fitting is used wherever airflow must be stepped down or stepped up between differing duct diameters, maintaining system balance and minimizing turbulence at the transition point. HVAC installers and sheet metal mechanics use fittings like this during new construction, retrofit, and duct modification work to connect branches of different sizes without fabricating custom transitions on site.\u003c\/p\u003e\n\u003cp\u003eThe RE043 is suited for residential and light commercial forced-air duct systems where a 4-inch to 3-inch transition is required. Common install scenarios include connecting supply trunk lines to smaller branch runs, adapting register boots to existing ductwork, or modifying duct layouts during renovation work. This fitting is appropriate for standard round duct systems using sheet metal or flexible duct connections.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eTransitions between 4-inch and 3-inch round duct diameters\u003c\/li\u003e\n  \u003cli\u003eDesigned for use in forced-air HVAC distribution and ventilation systems\u003c\/li\u003e\n  \u003cli\u003eEliminates the need for custom on-site fabrication at transition points\u003c\/li\u003e\n  \u003cli\u003eCompact form factor suited to tight mechanical spaces\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style replacement and standard fitting for residential and light commercial round duct systems requiring a 4-inch to 3-inch diameter transition.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation should be performed by a licensed HVAC technician or qualified sheet metal mechanic. Shut down the air handling unit and confirm the system is de-energized before beginning any duct modification. Secure the fitting using sheet metal screws and seal all joints with UL-listed duct tape or mastic sealant per local mechanical code requirements. Verify airflow direction and duct layout before finalizing the connection.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInlet Diameter\u003c\/strong\u003e: 4 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOutlet Diameter\u003c\/strong\u003e: 3 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFitting Type\u003c\/strong\u003e: Reducer-Increaser\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: AIR FLOW PRODUCTS\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: RE043\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"AIR FLOW PRODUCTS","offers":[{"title":"Default Title","offer_id":51344221077810,"sku":"RE043","price":19.57,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310554505.jpg?v=1782032212","url":"https:\/\/voomisupply.com\/products\/air-flow-products-re043-reducer-increaser-4-to-3-inch","provider":"Voomi Supply","version":"1.0","type":"link"}