Question

A composite plane wall consists of a 5-in.-thick layer of
insulation (*k*_{s} = 0.029 Btu/h · ft · °R) and a
0.75-in.-thick layer of siding (*k*_{s} = 0.058
Btu/h · ft · °R). The inner temperature of the insulation is 67°F.
The outer temperature of the siding is 0°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·ft^{2} of surface area.

A) Determine at steady state the temperature at the interface of the two layers, in °F.

B) The rate of heat transfer through the wall in Btu/h·ft2 of surface area.

Answer #1

A composite wall 8.5 ft X 10.5 ft is made of 1.5-in.-thick
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the wall?

Steam at 350°F flows through a 3-in (ID) copper pipe having a
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at 130°F. The convection coefficients for steam and air are 25 and
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ambient is 30oC . The convective heat transfer
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A flat wall is exposed to an environmental temperature of 38
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degrees C. The wall loses heat to the environment by convection.
Compute the value of the convection heat transfer coefficient that
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The wall of an industrial furnace is constructed from a fireclay
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The outer surface wall temperature has a steady-state temperature
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lost from the outer surface wall via convection and radiation. The
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Convection heat transfer coefficient between outer wall and air:
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Stefan-Boltzmann constant σ:...

A carpenter builds an exterior house wall with a layer of wood
2.8 cm thick on the outside and a layer of Styrofoam insulation 2.3
cm thick on the inside wall surface. The wood has k=0.080W/(m⋅K),
and the Styrofoam has k= 0.010 W/(m⋅K). The interior surface
temperature is 19.0 ∘C , and the exterior surface temperature is
-11.0 ∘C .
Part A
What is the temperature at the plane where the wood meets the
Styrofoam?
Part B
What is the...

A house has a composite wall of wood (exterior) (k = 0.12 W m-1
K -1 , 20 mm thick), fibreglass insulation (k = 0.045 W m-1 K -1 ,
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mm thick). Determine the total heat loss through the wall when the
inside temperature is 20 °C, the outside temperature is -10 °C, the
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The wall of a refrigerator of 4m^2 surface area consists of two
metal sheets with insulation in between. The temperature of the
inner wall surface is 5 C and that of the outer surface is 20 C.
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the insulation is 0.017 W/m C. If the thickness of each metal sheet
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so that the heat transferred...

It is a question about the thermal heat transfer problem.
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respectively. The rate of heat flow through the whole wall is not
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How many Btu/hr are lost through a 100-square foot wall that is
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temperature is 40 degrees F and the inside temperature is 65
degrees F. Do not enter units. If the answer is one million Btu/hr,
enter 1.E6.

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