Air Conditioning - Optimizing second floor airflow for a/c

Well, it's that time of the year, again; time to adjust the dampers for a/c.

Most of the adjustments consist of opening up (fully) all of the upstairs runs, since they were slightly dampered during the heating season.

The downstairs runs for the most part are dampered down (more or less, depending on location) all of the year, since heating and cooling are more than adequate, there.

For cooling purposes, my question is whether I could gain better air flow upstairs, by opening all of the runs (fully) to improve supply side static, since theoretically, at constant fan, less static = greater CFMs.

Thanks for your thoughts.

Delta l

The little squirrel cage fans used in residential units cannot stand very much static pressure they will simply refuse to move air if they are met with to much resistance. If you have a newer unit you can probably pull up the performance specs on line from the manufacturer. The problem is that the instrument required to accurately take static pressure and CFM readings is very expensive. A Homeowner without proper tools can only take a wild guess so I would say yes just open them up and let it purr. Try to resist choking it down to force air to different vents. You might make a few calls to some of the local HVAC companies they might have a air balance guy that can come out and assist you for a reasonable fee.