A composite wall is made up of an external thickness of brickwork 110 mm thick inside which is a layer of fiberglass 75 mm thick. The fiberglass is faced internally by an insulating board 25 mm thick. The coefficient of thermal conductivity for the three are as follows: Brickwork 1.5 W/m-K Fiberglass 0.04 W/m-K Insulating board 0.06 W/m-K The surface transfer coefficients of the inside wall is 3.1 W/m2 -K while that of the outside wall is 2.5 W/m2 -K. Take the internal ambient temperature as 10°C and the external temperature is 27°C. Determine the heat loss through such wall 6 m high and 10 m long.

A composite wall is made up of an external thickness of brickwork 110 mm thick inside which is a layer of fiberglass 75 mm thick. The fiberglass is faced internally by an insulating board 25 mm thick. The coefficient of thermal conductivity for the three are as follows: Brickwork 1.5 W/m-K Fiberglass 0.04 W/m-K Insulating board 0.06 W/m-K The surface transfer coefficients of the inside wall is 3.1 W/m2 -K while that of the outside wall is 2.5 W/m2 -K. Take the internal ambient temperature as 10°C and the external temperature is 27°C. Determine the heat loss through such wall 6 m high and 10 m long.

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 1.35P: A section of a composite wall with the dimensions shown below has uniform temperatures of 200C and...

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Concept explainers

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a burner, heats up because of the flame underneath it.

Question

Brickwork 1.5 W/m-K
Fiberglass 0.04 W/m-K
Insulating board 0.06 W/m-K
The surface transfer coefficients of the inside wall is 3.1 W/m2

-K while that of the outside

wall is 2.5 W/m2

-K. Take the internal ambient temperature as 10°C and the external
temperature is 27°C. Determine the heat loss through such wall 6 m high and 10 m long.

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