Requested questions:Q1: A house has a composite wall of wood, fiberglass insula-tion, and plaster board, as indicated in the sketch. On acold winter day, the convection heat transfer coefficientsare h, = 60 W/m K and h, = 30 W/m2 K. The totalwall surface area is 350 m'.Glass fiber blanket(28 kg/m'), APlaster board,- Plywood siding. k,(a) Determine a symbolic expression for the total thermalresistance of the wall, including inside and outsideconvection effects for the prescribed conditions.InsideOutsideA, T20°cT-15°C111(b) Determine the total heat loss through the wall.(c) If the wind were blowing violently, raising h, to300 W/m K, determine the percentage increase in10 mm 100 mm-- 20 mmthe heat loss.Q2: The walls of a refrigerator are typically constructed by sand-wiching a layer of insulation between sheet metal panels.Consider a wall made from fiberglass insulation of thermalconductivity k, = 0.046 W/m K and thickness L, = 50 mmand steel panels. each of thermal conductivity k, = 60W/m K and thickness L, = 3 mm. If the wall separates re-frigerated air at T = 4°C from ambient air at T= 25°C,what is the heat gain per unit surface area? Coefficients as-sociated with natural convection at the inner and outer sur-faces may be approximated as h, = h, = 5 W/m · K.L = 0.050 mLp = 0.003rRefrigeratedToi = 4°Ch = 5 W/m2-K44 Tmo = 25°Cho = 5 W/m2-KPanel (2)kp = 60 W/m-KInsulationk = 0.046 W/m-K

We will answer the first question since the exact one was not specified. Please submit a new…

Q1: A house has a composite wall of wood, fiberglass insula- tion, and plaster board, as indicated in the sketch. On a cold winter day, the convection heat transfer coefficients are h, = 60 W/m.K and h, = 30 Wf/m²-K. The total wall surface area is 350 m'. Glass fiber blarket (28 kgm'), A Plaster board. -Piywood siding. A, (a) Determine a symbolic expression for the total thermal resistance of the wall, including inside and outside convection effects for the prescribed conditions. Inside Datside 4.T 20°c 11 111 (b) Determine the total heat loss through the wall. (c) If the wind were blowing violently, raising h, to 300 W/m K, determine the percentage increase in the heat loss. 10 mm 100 mm 20 mm

Q1: A house has a composite wall of wood, fiberglass insula- tion, and plaster board, as indicated in the sketch. On a cold winter day, the convection heat transfer coefficients are h, = 60 W/m.K and h, = 30 Wf/m²-K. The total wall surface area is 350 m'. Glass fiber blarket (28 kgm'), A Plaster board. -Piywood siding. A, (a) Determine a symbolic expression for the total thermal resistance of the wall, including inside and outside convection effects for the prescribed conditions. Inside Datside 4.T 20°c 11 111 (b) Determine the total heat loss through the wall. (c) If the wind were blowing violently, raising h, to 300 W/m K, determine the percentage increase in the heat loss. 10 mm 100 mm 20 mm

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.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.42P

See similar textbooks

Similar questions

The air-conditioning system in a Chevrolet van for use in desert climates is to be sized. The system is to maintain an interior temperature of 20C when the van travels at 100 km/h through dry air at 30C at night. If the top of the van is idealized as a flat plate 6 m long and 2 m wide and the sides as flat plates 3 m tall and 6 m long, estimate the rate at which heat must be removed from the interior to maintain the specified
One end of a 0.3-m-long steel rod is connected to a wall at 204C. The other end is connected to a wall that is maintained at 93C. Air is blown across the rod so that a heat transfer coefficient of 17W/m2 K is maintained over the entire surface. If the diameter of the rod is 5 cm and the temperature of the air is 38C, what is the net rate of heat loss to the air?
The handle of a ladle used for pouring molten lead is 30 cm long. Originally the handle was made of 1.9cm1.25cm mild steel bar stock. To reduce the grip temperature, it is proposed to form the handle of tubing 0.15 cm thick to the same rectangular shape. If the average heat transfer coefficient over the handle surface is 14 W/m K, estimate the reduction of the temperature at the grip in air at 21C.
3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the atmosphere from outer space. If its original temperature is 38°C, the effective average temperature of the atmosphere is 1093°C, and the effective heat transfer coefficient is , estimate the temperature of the shell after reentry, assuming the time of reentry is 10 min and the interior of the shell is evacuated.
1.1 On a cold winter day, the outer surface of a 0.2-m-thick concrete wall of a warehouse is exposed to temperature of –5°C, while the inner surface is kept at 20°C. The thermal conductivity of the concrete is 1.2 W/m K. Determine the heat loss through the wall, which is 10-m long and 3-m high. Problem 1.1
Question 3: A house has a composite wall of wood, fiberglass insulation, and plaster board, as indicated in the sketch. On a cold winter day the convection heat transfer coefficients are ho 60 W/m2 K and hi 30 W/m2 K. The total wall surface area is 350 m2. (a)Determine the total heat loss through the wall. (b) If the wind were blowing violently, raising ho to 300 W/m2 K, determine the percentage increase in the heat loss.
Question:- A cylindrical steel tank with a diameter of 3 m and height of 4.4 m is used to store chilled water (at 9.3 °C) as part of an air conditioning system for a building. The heat transfer (convection) co-efficient for the surface of the tank in contact with the water in this application is 15 W/(m2.K). Given the surface temperature of the metal tank is 40 °C. At what rate must heat energy be removed from the water just to maintain its temperature constant at 9.3 °C ? Assume the tank is an enclosed cylinder and that the tank is always full. Note - the thickness of the tank is not relevant to this problem. Work in base SI units.
A steam turbine casing is made of a 6mm thick steel plate. At one location it has an inside surfacetemperature of 100°C. The convective heat transfer coefficient on the outside is 10 W/m2K. Theambient temperature is 25°C. What is the outer surface temperature? If the outer surface iscovered with a 3cm layer of insulation (k = 0.04 W mK), will it be safe to touch? Explain.
Question 1: A glass window of width W = 1 m and height H = 2m is 5 mm thick and has a thermal conductivity of kg =1.4 W/m.K. If the inner and outer surface temperatures of the glass are 15 °C and -20 C, respectively, on a cold winter day, what is the rate of heat loss through the glass? To reduce heat loss through windows, it is customary to use a double pane construction in which adjoining panes are separated by an air space. If the spacing is 10 mm and the glass surfaces in contact with the air have temperatures of (last two digit of your Registration number) °C and -15 °C, what is the rate of heat loss from a 1 mx2mwindow? The thermal conductivity of air is ka = 0.024 W/m.K.
How to Solve this, A stainless steel plate at 100◦C faces a firebrick wall at 500◦C.Esti- mate the heat flux and radiation heat transfer coefficient, h
Convection heat transfer from a plate (2 m x 2 m) is 450 W. If surface temperature of plate is 450 K and surrounding temperature is 300 K, what will be value of heat transfer coefficient?
15. The wall of a building consists of a 360-mm thick layer A which has a thermal conductivity, kA - 4.9 W/m-K, followed by a 80-mm thick second layer, layer B, which has a thermal conductivity, kg = 0.9 W/m-K. The inside and outside convection coefficients are 20 W/m² K and 39 W/m2 K. At these conditions, what is the overall heat transfer coefficient for this composite wall? Express your answer in W/m^2 K.