A composite plane wall consists of a 5-in.-thick layer of insulation (k, = 0.029 Btu/h ft R) and a 0.75-in-thick layer of siding (k, = 0.058 Btu/h-ft- °R). The inner temperature of the insulation is 67°F. The outer temperature of the siding is 8°F. Determine at steady state (a) the temperature at the interface of the two layers, in °F, and (b) the rate of heat transfer through the wall in Btu/h-ft2 of surface area. Part A Determine at steady state the temperature at the interface of the two layers, in °F. T₂= °F Part B The parts of this question must be completed in order. This part will be available when you complete the part above.

A composite plane wall consists of a 5-in.-thick layer of insulation (k, = 0.029 Btu/h ft R) and a 0.75-in-thick layer of siding (k, = 0.058 Btu/h-ft- °R). The inner temperature of the insulation is 67°F. The outer temperature of the siding is 8°F. Determine at steady state (a) the temperature at the interface of the two layers, in °F, and (b) the rate of heat transfer through the wall in Btu/h-ft2 of surface area. Part A Determine at steady state the temperature at the interface of the two layers, in °F. T₂= °F Part B The parts of this question must be completed in order. This part will be available when you complete the part above.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter2: Steady Heat Conduction

Section: Chapter Questions

Problem 2.2P: 2.2 A small dam, which is idealized by a large slab 1.2 m thick, is to be completely poured in a...

See similar textbooks

Similar questions

2.34 Show that the temperature distribution in a sphere of radius . made of a homogeneous material in which energy is released at a uniform rate per unit volume , is
2.55 A long, 1-cm-diameter electric copper cable is embedded in the center of a 25-cm-square concrete block. If the outside temperature of the concrete is 25oC and the rate of electrical energy dissipation in the cable is 150 W per meter length, determine temperatures at the outer surface and at the center of the cable.
A 0.6-cm-diameter mild steel rod at 38°C is suddenly immersed in a liquid at 93°C with h=110 W/m2 K. Determine the time required for the rod to warm to 88°C. Thermal conductivity (k) = 43 W/(m K); Specific heat (c) = 473 J/(kg K); Density = 7801 kg/m3 Thermal diffusivity (α) = 1.172 *10–5 m2/s.
3. A lumped system with a volume of 0.003 m³ and a surface area of 0.08 m² is made of a material with density of 3800 kg/m³, thermal conductivity of 300 W/m K, and specific heat of 200 J/kg K. If the system is exposed to a convection environment with h = 60 W/m2 K, what is the approximate time it will take for this system to reach equilibrium with the environment? Express your answer in minutes.
The inner and outer surfaces of a 0.5-cm-thick 2-m × 2-m window glass in winter are 15°C and 6°C, respectively. If the thermal conductivity of the glass is 0.78 W/m·°C, determine the amount of heat loss, in kJ, that occurs through the glass over a period of 10 h. What would your answer be if the glass were 1 cm thick?
THERMOFLUID A student living in a 3-m X 4-m X 4-m dormitory room turns on her 100-W fan before she leaves the room on a summer day, hoping that the room will be cooler when she comes back in the evening. Assuming all the doors and heat trans windows are tightly closed and disregarding any heat fer let through the walls and the windows, determine the temperature in the room when she comes back 8 h later. Use specific heat values at room temperature, and assume room to be at 100 kPa and 20°C in the morning she leaves.
Q 1.1: The inner and outer surfaces of a 5-m x 6-m brick wall of thickness 30 cm and thermal conductivity 0.69 W/m · °C are maintained at temperatures of 20°C and 5°C, respectively. Determine the rate of heat transfer through the wall, in W.
On a summer day in Phoenix, Arizona, the inside room temperature is maintained at 68° F while the outdoor air temperature is a sizzling 110° F . What is the outdoor– indoor temperature difference in (a) degrees Fahrenheit, (b) degrees Rankine, (c) degrees Celsius, and (d) kelvin? Is one degree temperature difference in Celsius equal to one temperature difference in kelvin, and is one degree temperature difference in Fahrenheit equal to one degree temperature difference in Rankine? If so, why?
A steel ball with a diameter of 10 mm is taken suddenly from a medium at a temperature of 25ºc and annealed for 20 minutes in the furnace host at a temperature of 800ºc. How many ° C is the temperature of the steel ball when it comes out of the oven? (ρ(steel) = 7854 kg / m3, C(steel) = 434 J / kgK, h(air) = 10 W / m2K and h(oil) =100 W / m2K) a. 705.65 b. 662.90 c. 706.25 d. 750.81 e. 750.20
The roof of an electrically heated home is 12m long, 16m wide, and 0.50m thick, and is made of a flat layer concrete whose thermal conductivity is k=0.8W/m 2 ·°C. The temperature of the inner and outer surfaces of the roof one night are measured to be 12°C and 1°C, respectively, for a period of 12 hours. Determine a) the rate of heat loss through the roof that night b) the cost of that heat loss to the home owner if the cost of electricity is $0.14/kWh.
The roof of an electrically heated home is 9 m long, 12 m wide, and 0.50 m thick, and is made of a flat layer of concrete whose thermal conductivity is k = 0.8 W/m · °C . The temperatures of the inner and the outer surfaces of the roof one night are measured to be 25°C and 5°C, respectively, for a period of half a day. Determine the rate of heat loss (hp) through the roof that night.
13. A thin flat plate is hanging on a string such that its top surface is exposed to a solar radiant flux of 800 W/m2. Both its top surface and bottom surface are exposed to a combined convection-radiation environment with combined h = 21.1 W/m²K. What is the temperature of the plate under steady state conditions if the ambient air temperature is 39°C? Express your answer in °C.