Ductwork Sizing Chart

Convert rectangular duct to round equivalent.

Ductwork sizing chart. While a duct sizing calculator built for a specific type of ductwork is the best possible method for sizing ducts the attached chart can be used in most single story homes with a centrally located unit and reasonable length duct runs. This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. The chart assumes the blower motor and total effective length of the duct system to be adequate for a 1 friction rate.

Larger volumes or higher static pressures should be dealt with on an individual job basis. As the trunks are reduced use the total cfm of the remaining downstream branches. Most technicians are skeptical about these numbers especially on the return air side of the system.

Air volume equivalent round air volume cfm 4 6 8 10 12 duct inches cfm 50 6 x 4 550 75 6 x 4 675 100 8 x 4 6 x 6 6 100 125 10 x 4 6 x 6 7 125. Ductulator calculats duct dimensions using equal friction method or velocity method. Friction rate velocity friction rate.

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. If you don t have one you can find them in the following links. We can use them to find the pressure drop per meter the.

The sizing chart is designed for estimating the airflow in an average system. Duct system sizes and airflow quick chart created date. These charts hold a lot of information.

To size the branch ducts select the duct size at the intersecting lines of the friction rate and the room cfm. And it shows the velocity and or static pressure loss of air for both types of duct shape. Online ductulator free duct size calculator.

Duct system design guide first edition 2003 mcgill airflow corporation mcgill airflow corporation one mission park groveport ohio 43125 duct system design. Include fittings in the duct tel enter either. In wg duct tel.

Convert diameter to rectangular equivalent. You can obtain these from ductwork manufacturers or from industry bodies such as cibse and ashrae. To size the ducts you re going to need a duct sizing chart.

For sizing the supply and return trunks select the duct size at the intersecting lines of the friction rate and the equipment cfm. It works with i p units united states united kingdom and metric units canada europe russia middle east asia. It calculates both rectangular and round duct dimensions.