Pittsburgh note
In humid Greater Pittsburgh summers, high SEER2 still disappoints if ducts, charge, and runtime cannot control moisture in the rooms you actually live in.
Higher isn’t automatically better for your house
A high SEER2 unit in starved ducts can still disappoint. Efficiency ratings assume proper airflow and charge — conditions many older Pittsburgh returns do not automatically provide.
How to use SEER2 on a quote
Compare matched indoor and outdoor models, not orphan outdoor-only swaps. Then ask how commissioning will verify that the installed system can approach the rated efficiency in your duct system.