Standard HVAC ductwork connections and fittings include rectangular-to-round takeoffs, shoe taps, bell mouths, and duct elbows. Full radius 90-degree and 45-degree elbows incorporate turning vanes with specific radius and spacing dimensions, while square 90-degree elbows are detailed for tight space conditions. Transitions feature slope restrictions not to exceed one inch in three inches. A specific note requires cutting holes in rectangular ducts large enough so rough metal edges do not project into the air stream.
ROUND DUCT CONICAL TEE FITTING WITH FLANGE RECTANGULAR DUCT AIR FLOW AIR FLOW RECTANGULAR DUCT ROUND DUCT TYPICAL TAKEOFF FROM RECTANGULAR TO ROUND DUCT - SHOE TAP TYPICAL TAKEOFF FROM RECTANGULAR TO RECTANGULAR DUCT - SHOE TAP RECTANGULAR DUCT AIR FLOW TYPICAL TAKEOFF FROM RECTANGULAR TO ROUND DUCT - BELL MOUTH 45° 45° 1-1/2" 1-1/2" ROUND DUCT RECTANGULAR DUCT TYPICAL RECTANGULAR TRANSITION TYPICAL RECTANGULAR TO ROUND TRANSITION DETAIL OF TURNING VANES SLOPE NOT TO EXCEED 1" IN 3" SLOPE NOT TO EXCEED 1" IN 3" 2" R W W W W W W C L C L SQUARE 90° ELBOW C L C L CONSTRUCTION OF 90° ELBOW 1 1/2 W FULL RADIUS 90° ELBOW FULL RADIUS 45° ELBOW TURNING VANES ( SEE DETAIL THIS SHEET ) USE THIS DESIGN WHERE 90° ROUND OR RECTANGULAR RADIUS ELS ARE SHOWN ON PLANS USE THIS DESIGN WHERE SQUARE 90° ELS ARE SHOWN ON PLANS OR IF SPACE CONDITIONS DO NOT PERMIT INSTALLATION OF RADIUS 90° ELS USE THIS DESIGN WHERE 45° ROUND OR RECTANGULAR RADIUS ELS ARE SHOWN ON PLANS 1 1/2 W NOTES: HOLE IN RECTANGULAR DUCT SHALL BE CUT LARGE ENOUGH SO THAT ROUGH METAL EDGE SHALL NOT PROJECT INTO AIR STREAM. 1.
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