Standard Hvac Duct Sizes

Flexible duct work must be stretched tightly for maximum air flow.

Standard hvac duct sizes. In order to maintain velocity reduce duct size. Equivalent diameter rectangular and circular hvac ducts equivalent diameter for rectangular and circular ducts air flows between 100 50000 cfm. The duct size must adequately handle air flow intake and return in order for an hvac system to operate at optimal levels. A comprehensive duct layout indicating sizes design airflows pressure class and routing of the duct system.

For this reason homeowners may want to contact a certified hvac technician or contractor to determine the optimal size of ductwork throughout the home or business environment that also measures up to code standards. Air ducts sizing air flow and required duct area. Maximum size of duct or pipe through steel joists k series joists and maximum size of ducts and pipes. Sizes of circular ventilation air ducts.

Never locate ducts at the end of the trunk line run. Sheet metal connectors inc. Link 1 and link 2. Always stagger take off ducts by 12 to maintain pressure.

Air ducts velocity diagram air flow volume duct. Smc manufactures coil line ductwork in 4 5 6 lengths. These charts hold a lot of information. Standard hvac duct sizes 2 how to size hot water baseboard heaters 3 how to calculate cfm in hvac 4 how to calculate furnace tonnage 5 the air return size for a furnace 6 the location of cold air return vents subscribe for weekly inspiration.

If you don t have one you can find them in the following links. To size the ducts you re going to need a duct sizing chart. Design cfm 4 cfm 6 cfm 8 cfm 10 cfm 12 60 6x4 60 4x6 90 4x8 120 4x10 150 4x12 90 8x4 110 6x6 160 6x8 215 6x10 270 6x12 120 10x4 160 8x6 230 8x8 310 8x10 400 8x12 150 12x4 215 10x6 310 10x8 430 10x10 550 10x12 180 14x4 270 12x6 400 12x8 550 12x10 680 12x12 210 16x4 320 14x6 490 14x8 670 14x10 800 14x12 240 18x4 375 16x6 580 16x8 800 16x10 950 16x12 270 20x4 430 18x6 670 18x8 930 18x10 1100. Air ducts friction loss diagram major loss diagram for air ducts si units.

You can obtain these from ductwork manufacturers or from industry bodies such as cibse and ashrae. Good engineering practices. 11 4 standard duct sizes. Use insulated duct or duct board in unheated spaces.

All ductwork comes standard with stiffening beads. Duct sizing how to size ductwork. Last take off run to be located 12 18 from end. Information required for duct construction 1.

The types of fittings to be used based on the designer s calculations of fitting losses i e square versus 45 entry taps conical versus straight taps etc. Rectangular duct and fittings are one part of our complete line of hvac products. 11 3 aspect ratio.