Riverside AC install work splits across two distinct neighborhood profiles. Older Wood Streets, Magnolia, and central Arlington homes built 1950-1990 are usually replacing 10-13 SEER R-22 split systems with current A2L (R-454B) equipment. These installs commonly require a refrigerant line set replacement (R-454B is incompatible with the mineral oil residue from R-22 systems) and sometimes return-duct upsizing because the original ducts were sized for low-static low-SEER equipment. Newer Mission Grove, Orangecrest, Canyon Crest tract homes (1990s-2010s) typically run their first replacement of original R-410A 14-16 SEER equipment now hitting the 12-15 year replacement window. These installs are usually cleaner — same-tonnage swap, same line set, modest efficiency upgrade. We size every install with a Manual J load calculation, not a rule-of-thumb tonnage spec, because Riverside summer afternoons regularly hit 100-105°F and undersized equipment never recovers from the heat once it falls behind.