Question

In: Physics

The inner and outer panes of a double-glazed window of dimensions 2 m x 2 m...

The inner and outer panes of a double-glazed window of dimensions 2 m x 2 m and 0.6 cm thick, the temperature is 18 ° C and 6 ° C, respectively. If the 1 cm gap between the two panes is filled with still air, determine the rate of heat transfer through the conduction air layer in kW and the temperatures at the air-glass interfaces. K air = 0.026 ? / ?.? and K glass = 0.85 ? / ?.k

Expert Solution

The rate of heat transfer is given by

Where d is the thickness and A is the area of the plates.

Here, we have 3 layes.

We have to find H and the temperature between the layers.

Let Ta be the temperature between the layer 1 and the air

So,

Here,

A = 2m*2m = 4 m^2

d glass = 0.6 cm = 0.006 m

T2 = 18 C

The heat reansfered through air is

HWere Tb is the temperature after the layer of air

d air = 1 cm = 0.01 m

For the last layer of glass

T1 = 6 C

Since energy must be conserved, all these heat values must be equal.

So,

Applying the values,

Solving the equations we get

and

genius_generous answered 2 years ago

What is the percentage change in the R-value of the window if double glazed window is...

What is the percentage change in the R-value of the window if double glazed window is used with 6.4 mm and 12.7 mm air in between as compared to single glazed window? Does the resistance increase linearly with the thickness of the space?.

heat transfer The double-glazed window with a height of 1.2m and a width of 2m has...

heat transfer The double-glazed window with a height of 1.2m and a width of 2m has a gap of stagnant air (k = 0.026W / m ° C) with a width of 12mm between the glass of 3mm (k = 0.78W / m ° C). On a day when the outside temperature is kept at 24 ° C, find the continuous heat transfer rate and inner surface temperature in this glass window. (Take the heat transfer coefficients h1 = 10W...

The inner and outer surface temperatures of a glass window 5 mm thick are 15 and...

The inner and outer surface temperatures of a glass window 5 mm thick are 15 and 5°C. The thermal resist- ance of the glass window due to conduction is Rt,cond = 1.19 × 10−3 K/W. What is the rate of heat loss through a 1 m × 3 m window? What is the thermal conductivity of the glass?

A picture window has dimensions of 1.40 m

Sound is passing perpendicularly through an open window whose dimensions are 1.1 m x 0.75 m....

Sound is passing perpendicularly through an open window whose dimensions are 1.1 m x 0.75 m. The sound intensity level is 83 dB above the threshold of human hearing. How much sound energy comes through the window in one hour?

Aspherical container of inner radius r1 2 m, outer radius r2 2.1 m, and thermal conductivity...

Aspherical container of inner radius r1 2 m, outer radius r2 2.1 m, and thermal conductivity k 30 W/m · °C is filled with iced water at 0°C. The container is gaining heat by convection from the surrounding air at T 25°C with a heat transfer coefficient of h 18 W/m2 · °C. Assuming the inner surface temperature of the container to be 0°C, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the...

A hollow, conducting sphere with an outer radius of .250 m and an inner radius of...

A hollow, conducting sphere with an outer radius of .250 m and an inner radius of .200 m has a uniform surface charge density of -6.37 muC/me2.When a charge is now introduced at the center of the cavity inside the sphere, the new charge density on the outside of the sphere is -4.46 muC/me2. What is the charge at the center of the cavity?

A hollow, conducting sphere with an outer radius of 0.240 m and an inner radius of...

A hollow, conducting sphere with an outer radius of 0.240 m and an inner radius of 0.200 m has a uniform surface charge density of +6.37 × 10−6 C/m2. A charge of -0.400 μC is now introduced into the cavity inside the sphere. What is the new charge density on the outside of the sphere? Express your answer with the appropriate units. Calculate the strength of the electric field just outside the sphere. Express your answer with the appropriate units....

A Styrofoam(k = 0.035 W/m-°C) box has outer dimensions of 250 mm x 450 mm x...

A Styrofoam(k = 0.035 W/m-°C) box has outer dimensions of 250 mm x 450 mm x 600 mm and is 3 cm thick. Initially, the box is filled with 40kg of ice at 0°C, and the inner surface temperature of the ice chest can always be taken to be 0°C. The heat transfer coefficient between the outer surface of box and surrounding air at 35°C is 20 W/m2 -°C. (a) Determine how long it will take for the ice in...

A conducting spherical shell with inner radius a=0.1 m and outer radius b=0.5 m has a...

A conducting spherical shell with inner radius a=0.1 m and outer radius b=0.5 m has a positive point charge Q=+5 nC located in its center. The total charge on the shell is -3Q and it is insulated from its surroundings. a. Calculate the surface charge density on the surfaces of the shell. b. Calculate the magnitude of the electric field at a radius of 0.01 m, and at a radius of 1.5 m. c. Sketch the electric field lines in...