Duct Sizing Hvac Cfm Chart

Calculate the duct size by using a duct calculator.

Duct sizing hvac cfm chart.

If a room is 250 square feet the result will be a duct size of 8 inch round. 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. For the same 2 5 ton system with a filter grille the grille size would need to be what size asked rick we usually use a 20 x 20 for 2 5 ton said the tech 20 x 20 x 2 800 800 cfm well that s big enough for a 2 ton but a 20 x 25 may be a better choice. Duct system sizes and airflow quick chart created date.

You can also do this by checking for them online or by using a manual that is sold by distributors. This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. The chart should not be used to design complete duct systems. The chart is based on metal duct.

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. Note also the return air grille sizing formula at the top of the chart. Larger volumes or higher static pressures should be dealt with on an individual job basis.