Hvac Flex Duct Sizing Chart

Like regular hvac duct flex duct work needs to be sized appropriately in order to flow the air volume which is measured in cubic feet per minute cfm correctly.

Hvac flex duct sizing chart.

In wg duct tel. 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. Duct sizing chart hey rick i heard that flex duct doesn t move the same amount of air as metal duct and my company primarily installs flex duct is that bad no replied rick but all ductwork needs to be sized differently and many of the rules have not been fully brought into practice. Include fittings in the duct tel enter either.

To size a flex duct you utilize the same methods as if you were sizing regular hvac rigid 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 round duct size estimate. Larger volumes or higher static pressures should be dealt with on an individual. Residential duct sizing guide key points to remember when using this guide the sizing chart is designed for estimating the airflow in an average system.

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. Metal ductboard flex size by. 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 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. Residential duct sizing guide the following duct sizes are based on a fraction drop of 10 inches per 100 feet of lineal duct.

Friction rate velocity friction rate. The chart assumes the blower motor and total effective length of the duct system to be adequate for a 1 friction rate. Velocity duct sizing chart residential main supply trunk ducts non zoned systems target velocity of 800fpm used listed by air quantity round duct size and nearest square duct size 500cfm 11 ø or 10 x 10 1 300cfm 16 ø or 14 x 16 600cfm 12 ø or 10 x 12 1 400cfm 18 ø or 16 x 16.