Can you explain my Chevy truck's ventilation controls?

Chevrolet Silverado – low end.

Situation:
-> AC button is OFF
-> Ventilation button is pointing to face and feet (in other words, NOT defroster or and not to window)

When the Recirc button is pressed, I get
a) more air being circulated
b) but it seems cooled/refrigerated

When the recirc button is not pressed, I get
a) less air coming through the fan
b) ‘normal’ ambient air temperature, doesn’t appear to be cooled

Is the recirculated air being cooled by the AC even though the ACbutton is off? Or is the air being cooled by the fan/radiator without the need for additional refrigeration, and it just feels cooler to me?