Hvac Flex Duct Sizing Chart

Metal ductboard flex size by.

Hvac flex duct sizing chart. 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. In wg duct tel. Include fittings in the duct tel enter either. 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.

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. Convert rectangular duct to round equivalent. The chart assumes the blower motor and total effective length of the duct system to be adequate for a 1 friction rate. To size a flex duct you utilize the same methods as if you were sizing regular hvac rigid duct.

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. Larger volumes or higher static pressures should be dealt with on an individual. Duct system sizes and airflow quick chart created date.

Friction rate velocity friction rate. 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.