Agree About Not Closing Vents
https://zukoski-group.chbe.illinois.edu/index/index.php/Getting_Your_AC_Ready_for_Summer_With_a_Comfort_Experts_Plan_to_Avoid_North_Fort_Worth_AC_Repair_Calls
Agree About Not Closing Vents Agree with the point about not closing too many vents. I used to shut them in the guest rooms to cut energy use, and the system started whistling and running longer. Opened them back up and things calmed down