{"product_id":"air-flow-products-77202018-transition-boot-20x20-18-inch","title":"Air Flow Products 77202018 Transition Boot 20x20 18 Inch","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe AIR FLOW PRODUCTS 77202018 is a straight transition boot with flange, designed to connect a square or rectangular duct opening to a round collar in low-pressure supply or return air duct systems. Built to the 77F configuration, it transitions from a 20x20 inch square opening to an 18 inch round collar, allowing installers to adapt plenum or trunk-line duct runs to round branch takeoffs. HVAC technicians and sheet metal contractors install this fitting during new construction or system modification work where a clean, flanged connection is required at the air handler, grille, or diffuser interface.\u003c\/p\u003e\n\u003cp\u003eThis boot is suited for residential and light commercial forced-air HVAC installations. The flanged design simplifies attachment to ceiling, floor, or wall openings, providing a secure mounting surface for grille or diffuser fastening. The straight geometry keeps airflow transitions direct with minimal turbulence, making it appropriate for supply trunk extensions and return air plenums that require a square-to-round adapter at the termination point.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eStraight transition geometry from 20x20 inch square to 18 inch round collar\u003c\/li\u003e\n  \u003cli\u003eFlanged perimeter provides a positive mounting surface for grille or diffuser attachment\u003c\/li\u003e\n  \u003cli\u003e77F configuration designed for direct, low-offset duct transitions\u003c\/li\u003e\n  \u003cli\u003eSized for high-volume branch or trunk terminations in forced-air systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style sheet metal fitting for use in residential and light commercial forced-air duct systems requiring a square-to-round transition at a 20x20 inch duct opening with an 18 inch round collar.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is typically performed by licensed HVAC technicians or sheet metal contractors. Shut down the air handling unit and lock out power before connecting or sealing any duct fitting. Secure the boot to the duct opening with sheet metal screws and seal all joints with UL 181-rated mastic or foil tape per local mechanical code requirements. Verify that the round collar connection to the branch duct is properly supported to prevent stress on the joint.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConfiguration\u003c\/strong\u003e: 77F Straight Transition with Flange\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTransition Type\u003c\/strong\u003e: Square to Round\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSquare Opening Size\u003c\/strong\u003e: 20x20 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRound Collar Diameter\u003c\/strong\u003e: 18 inches\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: 77202018\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"AIR FLOW PRODUCTS","offers":[{"title":"Default Title","offer_id":51345737580850,"sku":"77202018","price":89.93,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310552902.jpg?v=1782062171","url":"https:\/\/voomisupply.com\/products\/air-flow-products-77202018-transition-boot-20x20-18-inch","provider":"Voomi Supply","version":"1.0","type":"link"}