Document 4v6OZZYp9k63r1Jkd1aJd3G2a

642 CHAPTER 31 1950 Guide Air Duct Design - 643 CU. FT OF AIR PER MINUTE CU FT OF AIR PER MINUTE .. . , - ' For Volumes of'10 to 2000 cfm . i(Based on Standard Air of 0.075 lb per cu ft density flawing through average, cleans round; galvanized mutwl ducts having approximately 40 joints per 100 ft.) No safety factor included. Caution: Do not extrapo late below chart. Fio. 2. Friction op Air in Straight Ducts For Volumes of 1000 to 100,000 cfm (Based on Standard Air of 0.075 lb per cu ft density flowing-through average, clean, round, galvanized1 metal ducts having approximately 40 joints per 100 ft.) No safety factor Included. Caution- Do not extrapolate below chart. Figs. 1 and 2, covering volume ranges of 10 to 2000 cfm, and 1000 to 100,000 . cfm', respectively. These charts were developed by the A.S.H.V.E. Re search Laboratory.! They do not include any safety factor. .The charts, Figs. 1 and 2, were constructed from the basic flow equationfor the pressure loss in circular ducts (see Chapter 4):