Energy Efficient AC unit by returning air to the building

[Dreebs]

Homework Statement

You arrange your climate control system so that as it pumps heat out of the cabaret air and thereby chills and dries that air. Part of the heat your system removes from the cabaret air goes to the outdoor air and part goes back to the cabaret air. It turns out that delivering some of this heat to the cooler, cabaret air (rather than to the hotter, outdoor air) makes the system more energy efficient--it uses less electricity! Why?
Select one:
a. When you add heat to the colder cabaret air, most of that heat becomes entropy. Having that additional entropy allows your system to consume less electricity.
b. The cabaret air is denser than is the outdoor air, so it can absorb more heat than the outdoor air.
c. The cabaret air is closer to your system than is the outdoor air, so it takes less electricity to convey the heat to the nearer cabaret air.
d. The smaller the temperature difference between the system's heat-absorbing cold surface and the air to which your system is pumping heat, the less ordered energy the system must consume to transfer each joule of heat.

Homework Equations

N/A

The Attempt at a Solution

D. If there is little difference in temperature, the amount of energy required to transfer the heat would be lower.

 

[jim hardy]

Sounds to me like a test question.
Test-taking is sometimes more playing cat-and-mouse with whoever wrote the questions than it is good science.While I'm not convinced the problem statement is a true one
it seems to me there should be at least one relevant equation.

I know there IS a formula for Carnot efficiency that has temperature terms in it.
Does it mesh up with any of the multiple choice answers that are offered ?
If so, that's probably what the author had in mind.