Hvac Duct Sizing Chart

Using an hvac duct sizing calculator your overall ducting size comes from combining the size cfm and friction loss of your home meaning it ends up being a pretty complicated calculation.

Hvac duct sizing chart. Larger volumes or higher static pressures should be dealt with on an individual. Step 4 determine the cubic feet per minute and duct sizes for all the rooms. The velocity reduction method can be used when sizing air 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.

Select suitable velocities for main and branch ducts from the table below. Field duct sizing chart rectangular sheet metal duct 07 on most metal duct calculators step one identify the volume of air that will be passing through the duct step two select the duct size from the table that can carry that volume of air step three if desired airflow exceeds the cfm rating increase to the next duct size. Most technicians are skeptical about these numbers especially on the return air side of the system. Hvac calculations and duct sizing 2012 instructor.

Find the sizes of main and branch ducts from the air flow rates and the velocities by using eq. The method can be summarized to. This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. 1 and the charts below.

You can also do this by checking for them online or by using a manual that is sold by distributors. Pdh online pdh center 5272 meadow estates drive fairfax va 22030 6658 phone fax. Residential duct sizing guide the following duct sizes are based on a fraction drop of 10 inches per 100 feet of lineal duct. Duct system sizes and airflow quick chart created date.

If a room is 250 square feet the result will be a duct size of 8 inch round.