When it's cool outside, use the fan to suck air in....windows open helps.
When hot inside, use fan to blow air out so A/C doesn't have to work so hard to cool the interior.....then off once temp inside is dropping, windows closed.
Just how I do it.
2012 Fun Finder XT 276 Toy Hauler & Harley Davidson Ultra Classic with Condor wheel chock
2014 Dodge Ram 2500 AT 4X4 Crew Cab 6.4 L Hemi, 373 gears, tow package, Rambox option, Revolver X2 tonneau cover, Equal-I-zer anti-sway hitch.