Why are smaller places hotter than larger places ?

Dear student,
Your question is not clear and appears to be incomplete.
Considering your question to be about "why smaller rooms are hotter than larger place?"
here is the solution;
The air temperature of a smaller room without ventilation is higher than any larger room. As with increasing space in the room, the flow of air is smooth.Thus the room temperature of bigger room is lower that that of small room. Though there are more significant factors that effect the room temperature. these are;

1. Dirty air filter
2. Closed vents
3. Open windows

And scientifically, the size of room has less significant effect on the room temperature.

If you have something else in your mind, please repost the complete question in a separate thread. Look forward to hearing from you again!
Regards