Hvac Flex Duct Calculator

While this may be true in most cases for a metal supply air duct it is not for a metal return nor a 6 flexible duct on supply or return.

Hvac flex duct calculator.

Use the online duct calculator see references and calculate the needed flex duct size. Select the duct type on the pull down menu. Sheet metal duct friction loss calculator. Friction rate velocity friction rate.

Read round duct diameter inches and friction loss per 100 of duct inches of water. Convert rectangular duct to round equivalent. The furnace s british thermal units btus will help calculate the size it needs. Flexible duct round metal pipe 750 1200 14 16 design airflow 50 85 125 1500 2000 180 240 325.

If ashrae 2013 is selected flexible roughness is 0 003 ft when straight and fully stretched tight at 0 compression adjusted at other compressions otherwise the. This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. Residential duct sizing guide the following duct sizes are based on a fraction drop of 10 inches per 100 feet of lineal duct. In wg duct tel.

Calculations are for 60 f dry air at sea level from 5 to 3000 cfm approximately standard air which is 0 075lb da ft. Based on duct diameter. Read duct diameter inches and duct velocity fpm. Input the required cfm in the box below that.

Include fittings in the duct tel enter either. Larger volumes or higher static pressures should be dealt with on an individual. Enter duct airflow cfm duct velocity fpm duct length and the number of bends. Metal ductboard flex size by.

In order for your forced air furnace to work properly you have to have the right sizes of duct vents in each room expelling air. A round duct with a cross sectional area of 0 6m2 has a perimeter of 2 75m a rectangular duct with an equal cross sectional area has a perimeter of 3 87m the rectangular duct therefore requires more metal for its construction this adds more weight and costs to the design. Rectangular duct is rounded up to the nearest 1 4 inch. Enter the desired length of the rectangular 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 duct height net inside dimension in inches. Enter round duct diameter. Click calculate and you will see the size of flex duct you need for that room. The flex duct size may be different than the hard duct that runs to that room.

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.