Rectangular duct sizes Common HVAC duct sizes for home systems range from 8x8 inches to 24x24 inches, with smaller ducts used for branch lines and larger ducts for main trunks. Example: How many CFM does a 6-inch duct have? A rectangular 6×6-inch duct has an airflow of 110 CFM. rectangular duct and fittings are one part of our complete line of HVAC products. However, non-professionals can use the round duct friction loss chart to calculate the round duct size and then, convert it into rectangular duct size if needed. All rectangular duct fittings are fabricated with stiffening beads on duct sizes 19” wide and larger which have more than 10 square feet of unbraced panel. 05" on most metal duct calculator Round metal pipe = . Oct 2, 2020 · These are often used when the depth of the rectangular duct is less than the round size of the branch being connected. HVAC – How to Enter an internal duct size (this must be limited to a maximum aspect ratio of 5:1 for the results to be valid) The resulting vel ocity and pressure drop per unit length are displayed in the blue box. Flex duct = . Fittings are manufactured on our state of the art fabrica-tion equipment. PRESSURE LOSSES IN AIR DISTRIBUTION SYSTEM . Sep 23, 2021 · Rectangular HVAC Duct Sizing. 4 Equivalent Diameter . 07" on most metal duct calculators Duct Size “What size should my ducts be?” The dimensions of ducts (be it flex, metal, round, or rectangular) determines the airflow (measured in CFM). All fittings are fabricated with stiffening beads on duct sizes 19” wide and larger which have more than 10 Rectangular Duct Fittings Sheet Metal Connectors, Inc. 3 Static Regain Method . These include: Round flex duct: 5 inch – 20 inch; Metal round pipe: 5 inch – 20 inch; 4 inch rectangular duct: 6 inch – 24 inch diameter; 6 inch rectangular duct: 4 inch – 30 inch diameter; 8 inch rectangular duct: 4 inch – 36 inch diameter Commonly used rectangular duct sizes in air handling ventilation systems: Rectangular Ducts - Dimensions; Width (mm) Height (mm) 100 150 200 250 300 400 500 600 800 1000 Dec 31, 2024 · Duct Size Chart. This is the Tujiha Ducts range of rectangular ducts and fittings for HVAC systems. 2 Rectangular Ducts . All ductwork comes standard with stiffening beads. Duct work is otherwise called as duct system. 0. 7mm to 0. One size is given for round ducts, its diameter. SMC manufactures coil line ductwork in 4’-5’-6’ lengths. 1 Duct Friction Losses . 3 The Concept of Duct Equivalent Length . We have coil lines that fabricate straight duct with the following options: Fittings Snap-Rite manufactures rectangular fittings in most sizes & configurations. This catalog presents the rectangular ducts and fittings sized in accordance with SMACNA- Sheet Metal and Air conditioning Contractors' National Association Inc-" HVAC Duct Construction Standards- Metal and Flexible"-THIRD EDITION -2005, U. (SMC) TDC, Slip/Drive and Raw Sheet Metal Connectors, Inc. This type of fitting also offers the additional benefit of providing better air flow characteristics. Provided here is the rectangular duct sizes chart for your personal reference and this chart / table shows the duct size (cfm) and their equivalent diameter in inches. Select the duct material from the drop-down list (most duct sizing tools are typically based on galvanised steel ducting by default) Enter the air flowrate in cubic feet per minute (CFM) Enter an internal duct size in inches (this must be limited to a maximum aspect ratio of 5:1 for the results to be valid) Mar 10, 2025 · Rectangular Duct Sizes. You have two or three options for rectangular ducts that give you the same or nearly the same square footage per duct. Sheet Metal Connectors, Inc. 2 Velocity Reduction Method . 9mm galvanised mild steel depending on size. manufactures rectangular duct fittings in most sizes and configurations on state-of-the-art fabrication equipment. Rectangular Duct and Fittings McGill AirFlow Corporation’s single-wall, rectangular duct and fittings are factory fabricated to furnish you with a high-quality line of products in a broad range of standard sizes. 1 Equal friction method . Additionally, by offering flexibility in duct shape options such as round equivalent and rectangular equivalent diameter, the calculator ensures that users can accurately size ductwork for a wide range of HVAC applications, from residential homes to commercial buildings. Feb 19, 2024 · Standard Air Duct Sizes. The length of the rectangular duct size would range from 0. Rectangular or square ducting comes in standard sizes ranging from 3 inches by 7 inches to 35 inches by 40 inches. . 6. 2 Duct Fitting Dynamic Losses . The equivalent diameter is the diameter of a circular duct or pipe that gives the same pressure loss as an equivalent rectangular duct or pipe. The table below can be used to compare equivalent diameters for rectangular and round circular ducts. 3 Oval Ducts . For example this allows for a 12” round spiral duct to be attached to the side of a rectangular duct that is only 10” high. 5. 06" on most metal duct calculators Rectangular sheet metal duct = . 4. In this guide, we will cover the importance of accurate duct sizing, the consequences of incorrect sizing, an overview of typical sizes, and detailed formulas and examples for circular and rectangular ducts. We have included charts for most of the popular standard air duct sizes. Do your own calculations and compare them to our chart – or use the chart for quick, accurate calculations for duct size based on CFM needed for a room. Rectangular duct Mar 26, 2024 · So, how do you calculate the size of round ducts and rectangular ducts? Normally, engineers use simple software or a ductulator (provided by suppliers) to determine the size of a duct. Rectangular ducts and fittings are designed for low- and medium Rectangular Single Wall Duct (Ductwork) & Fittings. Bigger 6×12-inch ducts can handle 270 CFM airflow. Rectangular or square duct sizes vary widely and are chosen based on airflow requirements and spatial restraints. Understanding how to calculate duct size for your HVAC system is crucial for ensuring efficiency, performance, and longevity. DUCT SIZING . SA. The table is based on the ducts friction loss formula. To minimize field-assembly costs, rectangular duct is supplied in lengths up to 6 feet. hops cvgtw mqzgi iyuahvs aqfki dxrc ddqd unutf aaawtn kzjyu rhdy osferao swqlo dvuevxxc yuili