Document ypr9NZgpRZ1Q2dVLmXwM3B7J6

474 CHAPTER 20 -i-JDRiO-iUilPor*1 WEAORuMivALAEIRNTANCD.ENRCETTi!oURBNASAEIDR-W0OjNrNEDETPTOHR OPfLEDNUUCTM. 1955 Guide Forced Warm Air Systems 475 I NOT RECOMMgHOCe GROUPS' Angles and Elbows tor trunk ducts, name raws '/ width.of duct. EQUIVALEN T LENGTHS ttASEO ON 8: DEPTH OF OUCT ^ A, , 'Tv . 4 20 TO TO TO 15 27* 22* 8 , U n * rt - ' . i ** W0TN' * TO II a #0 t9. I 12 TO 21 *. S T 22 to 27 20 -; 29 TO 32*25 ...-V .,^*r WIDTH' 4 TO 20 co. rr. >. ;.7 to n . 40. 12 TO 15 " 55 .I .' io'.TD 2l * 75 22 TO 27 - IOO. 20 TO 32.* 125 Ni*'# .. 4 TO II iS t0.ri (2 TO 21 * 20 22 TO 27* 25 20 TO 32 40 GROUP 5^ "c="===*" STACK ANGLES, ELBOWS, AND COMBINATIONS. A AND a HAVE 3" THROAT RADIUS O AND E HAVE 5" THROAT RADIUS tFig.' . Equivalent Length* op Fittings RETURN AIR LINER TO DUCT. STUD SPACE TO LINER. STUD SPACE TO LINER. Fig. 4. Equivalent Length of Fittings (Continued) r: i- Design of duct system'.............. ....... - --' ........... A. Warm air branches. - ~ a. Use Table'7 to select maximum 'bonnet' pressure usually required for the trunk carrying the maximum volume of air (cfm). If the maximum ft