If the goal is to make the room cooler, your teacher is right. If the goal is to make the students cooler, then the 4th graders are right. 4th graders sweat, and the fan will cause convective cooling of the 4th graders.
This is a concept often poorly understood in basic cooling design. Even without sweat, if your AC vent is blowing directly on you the temperature it is at needs to be vastly different than that of air being using to more actively cool the entire room.
This is often a key difference between Car and Room AC systems.
There’s also a surprising gradient based on how consistent the temperature is top to bottom (and you get into trouble with this on reverse cycle AC systems)
And lastly it’s easy to ignore radiant heat from both walls/ceilings as well as even large monitors.
This is often a key difference between Car and Room AC systems.
There’s also a surprising gradient based on how consistent the temperature is top to bottom (and you get into trouble with this on reverse cycle AC systems)
And lastly it’s easy to ignore radiant heat from both walls/ceilings as well as even large monitors.
It all plays in together.