Unformatted text preview: W 666 C/W 02253 . C ) 8 23 ( ins no total, 2 1 = ° ° − = − = ∞ R T T Q & ( a ) The rate of heat transfer after insulation is W 9 . 99 666 15 . 15 . ins no ins = × = = Q Q & & The total thermal resistance with the foam insulation is C) W.m/ 42 . ( C/W 02253 . ) m C)(16.8 W/m. 025 . ( C/W 02253 . 4 2 4 conv,2 foam 3 2 1 total ° + ° = ° + ° = + + + + = L L R R R R R R T 1 T ∞ 2 R 2 R 3 R 1 R ins R o The thickness of insulation is determined from cm 5.4 m 0.054 = = ⎯→ ⎯ ° + ° ° − = ⎯→ ⎯ − = ∞ 4 4 total 2 1 ins C) W.m/ 42 . ( C/W 02253 . C ) 8 23 ( W 9 . 99 L L R T T Q & The outer surface temperature of the wall is determined from C 8.3 ° = ⎯→ ⎯ ° ° − = ⎯→ ⎯ − = ∞ 2 2 conv 2 2 ins C/W 00350 . C ) 8 ( W 9 . 99 T T R T T Q & 3123...
View
Full Document
 Fall '10
 Dr.DanielArenas
 Thermodynamics, Mass, Heat, Heat Transfer, outer surface temperature, Qins

Click to edit the document details