Document ymo1v4378OzzjvvKxox6k38E

698 CHAPTER 32 1954 Guide Air Duct Design 699 CU FT OF AIR PER MINUTE Fig. 1. Friction of Air in Straight Ducts For Volumes of 10 to 2000 cfm (Based on Standard Air of 0.075 lb per cu ft density flowing through average, clean, round, galvanized a*1! ducta having approximately 40 joints per 100 ft.) No safety factor included. Caution: Do notextrapo*aw> below chart. Fig. 2. Fbiction of 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, galvanized Saetal ducta having approximately 40 joints per 100 ft.) No safety factorincluded* Pigs. 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.F. Re search Laboratory.1 They do not include any safely factor. The charts, Figs. 1 and 2, were constructed from the basic flow equation or the pressure loss in circular ducts (see Chapter 4):