Agree About Not Closing Vents
https://www.mediafire.com/file/i9u5w8ks04yjbdm/pdf-68397-48025.pdf/file
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