AC Repair
What Size AC Do I Need? Why Bigger Isn't Better in LA
Oversized systems short-cycle, leave humidity, and wear out fast. Manual J is the only honest answer.
December 18, 2025 5 min read
The problem with rule-of-thumb sizing
"500 sq ft per ton" was an old rule of thumb that ignored insulation, window quality, ceiling height, sun exposure, and infiltration. In well-sealed modern LA homes, you often need 30-40% less capacity than that rule suggests.
Oversized AC cools the air fast but doesn't run long enough to dehumidify, leaving rooms cold and clammy. It also short-cycles, killing the compressor years early.
Manual J is the right answer
A Manual J load calculation accounts for every variable, orientation, insulation R-value, glazing, infiltration, occupancy. Nice & Cool runs Manual J on every install at no extra cost. It takes us about an hour and saves you years of comfort headaches.