How does the flow of thermal energy through a closed window illustrate

[jaypee]

How does the flow of thermal energy through a closed window illustrate the second law of thermodynamics? Which direction is the flow when it is cold outside? How outside?

--Please note this is a textbook question I can't seem to answer.

 

[FZ+]

The second law says that all closed systems move towards a state of maximum entropy. In this case, entropy represents the nearness to equilibrium between the energy of the air inside, and the air outside. If we consider the room and outside the room as two components of a closed system, then when they are allowed to randomly mingle through the closed window, the net effect would be to move towards an equilibrium temperature. Hence, overall, the thermal energy moves out of the room into the colder exterior. Energy does go both ways in a random action, but the effect is the transfer of thermal energy out the window.

 

[Graeme Robinson]

The flow of thermal energy through a closed window illustrates the second law of thermodynamics by showing that heat naturally flows from a warmer object to a cooler object until both objects reach thermal equilibrium. In the case of a closed window, the warmer object is the inside of the room and the cooler object is the outside temperature.

According to the second law of thermodynamics, heat will always flow in the direction of increasing entropy, or disorder. In this case, the warmer room has a higher level of organization and lower entropy compared to the cooler outside temperature. As heat flows through the window, it increases the entropy of the room and decreases the entropy of the outside temperature, eventually leading to thermal equilibrium.

When it is cold outside, the flow of thermal energy through a closed window is from the inside of the room to the outside. This is because the inside of the room is warmer and has a higher level of thermal energy, while the outside is colder and has a lower level of thermal energy. The flow of heat will continue until both the inside and outside temperatures are equal, and thermal equilibrium is reached.