Thermal Energy when Heating and Cooling a Cabaret

Click For Summary
SUMMARY

The discussion centers on the thermal energy dynamics involved in reheating chilled air for a cabaret environment. The primary conclusion is that utilizing heat from the cooling system can inadvertently raise the cabaret air temperature above outdoor levels due to the principles of thermodynamics. Specifically, option D is identified as the correct reasoning: moving heat from a warmer source to a cooler area requires work, which generates additional thermal energy. This process results in the cabaret air exceeding the temperature of the outdoor air.

PREREQUISITES
  • Understanding of thermodynamic principles, particularly heat transfer.
  • Familiarity with entropy and its role in energy transformations.
  • Knowledge of the relationship between work and thermal energy generation.
  • Basic concepts of air conditioning systems and their operational mechanics.
NEXT STEPS
  • Research the laws of thermodynamics, focusing on the second law and entropy.
  • Explore the mechanics of heat pumps and their efficiency in heating and cooling applications.
  • Study the concept of thermal energy transfer in HVAC systems.
  • Learn about the implications of thermal energy management in indoor environments.
USEFUL FOR

Engineers, HVAC professionals, and anyone involved in climate control systems will benefit from this discussion, particularly those looking to optimize heating and cooling efficiency in enclosed spaces.

Dreebs
Messages
25
Reaction score
1

Homework Statement


Having chilled the air until it contains only the perfect amount of moisture, you want to reheat it to the ideal cabaret temperature. You could use an electric space heater or wood fire, but you already have another source of heat: the same system that chilled the air in the first place. Instead of sending its heat outdoors, you can use some of that heat to warm the chilled air back to room temperature. But you have to be careful: if you use all of the heat that's released by the cooling system, the cabaret air will become hotter than the outdoor air! Why?
a. When the entropy produced by the cooling system becomes thermal energy and is added to the cabaret air, it will increase the temperature of the cabaret air above that of the outdoor air.
b. Pumping the heat from cold to hot requires that some ordered energy, such as electricity, become disordered. If you return all the pumped heat plus the newly disordered electrical energy to the room air, its temperature will rise above its starting temperature.
c. Whenever you change the temperature of an object, you create thermal energy. With more thermal energy in the cabaret air than before you cooled it, the temperature of the cabaret air will rise above that of the outdoor air.
d. The heat released by the cooling system is located far from the cabaret. To convey that heat back from its hotter source to the colder cabaret air requires work and this work will become thermal energy in the cabaret air. With the addition of that new thermal energy, the temperature of the cabaret air will rise above that of the outdoor air.

Homework Equations


N/A

The Attempt at a Solution


D, in order to move anything work is required. When doing work on something like air thermal energy is created in the process. So by moving the already warm air + the newly created thermal energy back into the cabaret, the place will become hotter than before.
 
Physics news on Phys.org
I am unsure of this as well. I am thinking either B or D. More towards B, as it doesn't say anything about the heat being far away from the cabaret.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 30 ·
2
Replies
30
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K