Why it matters to you
In the Lowcountry, an oversized system cools the air quickly but shuts off before it removes much moisture, leaving the house cool and clammy. Getting tonnage right is as much about humidity as temperature.
Practical guidance
Ask every bidder how they sized the system; a Manual J load calculation beats a rule of thumb or simply matching the old unit. Insulation, window, and duct improvements since the last install can change the right size.
