Question

please answer all parts

1- (5 ) Consider a glass window (1mx1m) with a thickness of 10 mm, thermal conductivity k = 1.4 W/m . °C, and emissivity 1. The room and the walls that face the window are maintained at 20°C, and the outside air temperature is 10 °C and the outside surrounding temperature is 5 °C, with no winds. Following is a solution for a similar problem but conditions are different; understand this solution before your solve the following: a) Find the inner and outer surface temperatures of this window. b) Find the total amount of heat loss from the window. What is the percentage that total heat loss due to radiation. c) Solve (b) if the glass window is considered as an isothermal sheet (i.e., the conduction resistance is negligible) d) Consider the above conditions, but with wind speed of 20 km/hr, solve (b) again and discuss. Show the details of your solution. Assume any missing information with justifications.

Answer 1

Problem Diogram- SUNYVunding com = 20°C - Data Given! Inside room -embrature = 20°C Gloss thermal Concurlinity = 1.4 W/mic C Emmisivity = L baloll thickness = 10mm Outside air temprature = 10°C Surrounding lembrature = 56 Assumed Jala' for finding the wol temperature we need to Chrow resistance diagrom ano', por that we need to know Connection Coondiciont o; le Convetion Copy. when no winel = 20 Wmºk C: you porceel Comwe dion velve h will be high). Solutions Port 9 when wind speed 20kmichir = 120 wim? Is. Grimen that Inside room temprature and well temp. ore same so glass window will be in there thermal equilibrrum so . O .Trener surjal = 2

Now drow resistance diogrom; om = 1m2. TE2010.. T-10°C To netion ng - Answer. ownia ha a Aree = 1x! Now by boloning heet for series Commedia 20-0-T 20-10 0.010 0 + 1.4 Tių 20 20-T = 0.01 * C175) 20-T = 1.25 Toutaid = 18.75° Answer Part 6 Total head lose = Head lose by Conduidiont. Head loss by Comwelion et Head loss by radiodion 80; Head loss by Conduction = KA CTG-TO) = *1*(20–18:75). I 0:0) Heat los by Convention shal Turin Tsurtoumbling) . .20x1 (18.75-19) 175. watt . Head loss by Roolihin OACT'ToY in Kelvin scale a =5167x10-8x1 x C291.78 = 175 Watt

= 47.11 word) tals 1957.175 + 47.11 wody Answer B = 3571 I woodet Answer Poditione). - 07.11.xle = 11.864. Answer U7) answer 1 оди 397.11 glass is now replaced as isothermal steel then Conduction resis sonce will be negleséli and inside and outside woll demp. will be some so, - now & Tairs 10c. T:20"C1 T-arc ITIV Head Jocs by Corwelion shA (20-10) - 20x1x10 = 200 wool). Head loss by radiation = 5:67X10-8x1 * (29742889 54.18 wordt Total = 254.19 watt. Ansteuer Radiation) = 54.13 x 10 254.13 = 21-321. Ansa nswer 2S

[ 10U1107 Port O. now for forced Conwedion h = 120 wmile. Head loss by Conduction = 175 'while Head loss hy Convection = 1200) *C18.75-10) 13.1! = 1050 wall: Head loss by Radiation : 47.11 wady Todal : 1272.J! wal? Radiation o% - 3. 70327,