I recently had a 17 SEER 3 ton Gas/AC 2 stage system installed. I upgraded a 3 ton system. I have a 1700 square foot floor and I was told that the static pressure was high. I was told should be around .50. Believe it is around .8. The service guy cut a return in my basement, which is not part of this system.
My questions are...
1. Is cutting a return duct in the basedment ok (pros/cons).
2. What is the tolerence for static pressure, as I want to get my 17 SEER but I don't want to overkill? Do I need .5 exactly, or is .6 OK, etc.?