Flex Duct 90 Degree

Avoid installations where exposure to direct sunlight.

Flex duct 90 degree.

90 degree register box creates a right angle 90 degree transition from 6 in. On the vent end it connects to a boot usually made of sheet metal. Each 90 degree bend if properly made equates to about ten feet of flex duct so this little arrangement would normally equal 30 feet of flex duct. It can be installed with sheet metal screws.

Find flexible hvac duct fittings at lowe s today. Position one end of flexright elbow around neck of air device and the other under the flexible duct to form 90 elbow. Air register or grille. Master flow s adjustable elbows are used to make turns in runs of round pipe and flexible duct through 90.

The master flow 12 in. Using cable tie tensioning tool fasten cable tie around neck of air device to secure flexright. Round pipe or insulated flexible duct to a 12 in. Use greenseam snap pipe duct and fittings from grainger to help with your commercial and residential hvac applications.

Properly account for bends in the duct runs. For best results keep duct insulation out from under cable tie as it is tightened. Resistance to flow through bends is expressed in feet of straight flex duct. If a piece of flex duct is coming in horizontally and the boot opens up vertically the installer usually turns the flex duct to make a 90 degree angle right there at the boot.

After fixing so many bad flex jobs i have learned that flex has to be sized correctly be hung properly be stright as an arrow pulled as tight as is humanly possible and bends should be metal in your case two 90 metal ells put together will give you your 180 degree bend with the least amount of pressure loss. Simply strap the one size fits all flexflow elbow over the outer jacket of the flexible duct. Flexible duct shall not be installed to allow for possible future relocations of air terminal devices. This register box is made of 30 gauge galvanized steel to provide strength and durability.

A 90 degree bend has pressure drop equal to approximately twenty 20 lineal feet of flexi ble duct. Engineered with a leed qualifying zero voc gasket this ductwork can eliminate the need for additional sealing along the longitudinal seams and transverse joint. Generally i avoid flex if at all possible even though it costs more i do metal duct. The flexflow elbow maximizes airflow by economically forming any brand and any size of commercial or residential flexible duct into a highly efficient 90 degree elbow.

They are also crimped on one end to easily fit into a pipe or other fitting of the same diameter. Given the crimping at the lower left it s probably 100 feet or more. So each 90 degree bend will add. As you can see in the photo at right that puts stress on the flex duct which can lead to failure.