Q.2 A cooling coil with a face area of 40 ft² is supplied with chilled water at 42° F. The coil has a performance data as shown in Table 8.1 of textbook on page 469. It is desired to cool air entering the coil at 95° F db and 750 wb with a face velocity of 500 fpm to 60.3° F db, Assume that water temperature rise 10° F and water velocity = 6 ft/s, Determine the (a) the number rows of tubes required (b) the number of fins per foot (c) the final wet-bulb temperature (d) the heat transfer rate to the water, tons (e) the amount of water vapor dehumidified from the incoming air in lbm/hr (f) sensible and latent loads of the coil. - Answers: (a) # rows = 4 (b) FPF =120 (c) 58.6°F (d) 96.7 tons (e) water dehumidified=360.84 lbm/hr (f) qs = 63.62 tons; qu = 34.6 tons OTE N 2 FPS NOW F 31.6 Table 8.1 A Typical Catalog Data of a Chilled Water Cooling Coil (42°F, EWT) WTR 8 (By courtesy of Trane) " EDB/EWB 95/75 WTR 10 MEH LOB LWB MSH LOB LWB 120 12.8 683 11.3 763 3 MOH LOB LW 120 77 78.0 13.8 774 2 14.3 4. 714 15.7 STA 154 767 751 114 MA 144 726 TOS T 242 38 26.2 $5.4 204 BL L 36.7 54.5 36.4 14.3 37.5 $2.1 10 48 41.4 40.1 * 34.5 $23 1000 34.5 45.845A 451 450 MB MB Coll Face Area WTR Water Temperature Rise (F) Ips Water Velocity (sec) AT 30.3 14.1 LDB-Leaving Dry Bub LWB Leaving Wel Bub (F) EWT Entering Water Temperature When using turbulators, make selection based on double the actual water velocity 13 233 583 224 433 258 67.3 657 4 N