We close a few to force more air to certain areas, but just a few. Considering duct size and vent size compared to the quick cool vent size, a few wont hurt. As mentioned though, close too many and freeze it will.
A question I'd like to add as I can't remember if I ever got an answer, when our switches fan speeds from high to low, the fan shuts all the way off then kicks on in the lower speed. Compressor remains on. It's always done this, works fine, but the last unit I had did a smoother transition. The control box and t-stat have been changed due to another problem. Auto fan has always functioned like this.
How do y'all's transition from high to low or vise versa? Off then back on, or never quits running during the switch?
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.