During the winter, the inside of an average house is maintained at 20 °C, while the outside temperature is 0 °C. Assuming that the only mechanism of heat transfer is conduction, the walls are 10 cm thick and the heat conductivity of the walls is 0.5 W/(Km). a) Calculate the heat flux from the room to the surroundings in W/m2 . b) To reduce the heat loss through the walls, the material should be changed to an insulator material. The new overall conductivity will be 0.1 W/(Km); the thickness of the walls is maintained. Calculate the reduction of the heat flux through the walls compared to the initial case
Energy transfer
The flow of energy from one region to another region is referred to as energy transfer. Since energy is quantitative; it must be transferred to a body or a material to work or to heat the system.
Molar Specific Heat
Heat capacity is the amount of heat energy absorbed or released by a chemical substance per the change in temperature of that substance. The change in heat is also called enthalpy. The SI unit of heat capacity is Joules per Kelvin, which is (J K-1)
Thermal Properties of Matter
Thermal energy is described as one of the form of heat energy which flows from one body of higher temperature to the other with the lower temperature when these two bodies are placed in contact to each other. Heat is described as the form of energy which is transferred between the two systems or in between the systems and their surrounding by the virtue of difference in temperature. Calorimetry is that branch of science which helps in measuring the changes which are taking place in the heat energy of a given body.
During the winter, the inside of an average house is maintained at 20 °C, while the outside temperature is 0 °C. Assuming that the only mechanism of
conductivity of the walls is 0.5 W/(Km). a) Calculate the heat flux from the room to the surroundings in W/m2
. b) To reduce the heat loss through the walls, the material should be changed to an insulator material. The
new overall conductivity will be 0.1 W/(Km); the thickness of the walls is maintained. Calculate the reduction
of the heat flux through the walls compared to the initial case.
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