I am staying the summer in an old house (not my home) with a 2-year-old Lennox central A/C that has not been run for over a year.
The A/C seems weak on the ground floor where I spend all my time. The house has is no second floor.
Q#1. Should I close the A/C vents in 2 unused basement rooms?
Q#2. Can you suggest anything else that I should inspect etc to improve performance?
BertB (ordinary home user, obviously not an HVAC professional)