This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications.
Round hvac duct sizing chart.
To insure proper distribution of air volume dampers must be used for all branch runs.
The chart is based on metal duct.
Flex duct has a higher pressure drop and as such may require the size shown on this guide be increased by 1 round size for up to 800 cfm and 2 round sizes.
These duct chart are based on equal friction method with a friction loss value 0 1 inch 100ft.
Duct size chart calculate duct dimensions for both rectangular and round ducts.
Flex duct 05 on most metal duct calculator round metal pipe 06 on most metal duct calculators field duct sizing chart rectangular sheet metal duct 07 on most metal duct calculators duct size duct height net inside dimension in inches round duct size estimate.
Convert diameter to rectangular equivalent.
The chart should not be used to design complete duct systems.
Include fittings in the duct tel enter either.
Download free duct sizing chart pdf according to ashrae standard.
Duct system sizes and airflow quick chart created date.
Residential duct sizing guide the following duct sizes are based on a fraction drop of 10 inches per 100 feet of lineal duct.
Larger volumes or higher static pressures should be dealt with on an individual.