Flex Duct Cfm Ratings

As systems increase in efficiency the tolerances of how we have always done it will no longer be adequate.

Flex duct cfm ratings.

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. Our polyester cores are also. Duct work supplies are located on outside walls. They should not be located in the same area as the furnace nor.

You must have 400 cfm of air flow per ton of a c 1 ton equals 12 000 btu approximately 1 cfm of air is required to heat or cool 1 to 1 25 sq. Adjustment of duct design pressure rate for equivalent lengths. All hart cooley flexible duct products are performance tested in accordance with industry standards to ensure reliability and years of service. Standard elbows will have 1 5 centerline radius.

Our core is tested in accordance with adc fd 72 r1 for actual installation static pressure temperature performance and meets the ratings specified in our catalog. Based on duct diameter. Enter round duct diameter. Enter round duct diameter inches duct airflow cfm duct length and the number of bends.

Use the online duct calculator see references and calculate the needed flex duct size. Read friction loss inches of water and duct velocity fpm. Elbows 14 through 30 shall be. Click calculate and you will see the size of flex duct you need for that room.

Returns are located on inside walls. All round spiral duct and fittings shall be manufactured from g 90 galvanized steel conforming to astm and smacna standards. Enter the desired length of the rectangular duct. Total effective length feet 05 06 08 10 125 14 16 18 20 25 30 34 375 40 50 625 75 1 00 35 44 13 15 20 25 32 35 40 45 50 63 75 85 95 1 00 1 25 1 50 1 90 2 54.

The flex duct size may be different than the hard duct that runs to that room. Input the required cfm in the box below that. Other radii and vaned elbows are available as needed. For instance a 2 5 ton system approximately 400 cfm per ton would require 2 14 flexible return ducts or 1 very short flexible 18 duct to move the 1000 cfm required by the 2 5 ton system.