A ton is the standard measure of air conditioning capacity, equal to 12,000 BTUs of heat removal per hour. The name is a leftover from the ice era: one ton of cooling is roughly the heat absorbed by melting a ton of ice over a day. Residential systems typically range from 1.5 to 5 tons, and most single-family South Florida homes land between 2.5 and 4.
Why tonnage matters in South Florida
Tonnage is a Goldilocks number, and both directions of wrong are expensive. An undersized system runs endlessly on August afternoons and never catches up. But oversizing, which is the more common sin, is sneakier: the too-big system blasts the house to temperature in minutes and shuts off before it dehumidifies, leaving the home cold and clammy while short cycling pounds the compressor. In a humid climate, the oversized system is arguably the worse mistake, and “bigger is better” is precisely backwards.
How the right size is found
Correct sizing comes from a load calculation, which accounts for your home’s square footage, insulation, windows, orientation, and ductwork, not from copying whatever tonnage was bolted outside in 1998. Homes change: new windows, added insulation, a converted garage. The old unit’s size is a data point, not an answer.
What Kyzar checks
When we quote a replacement, sizing is calculated, not assumed. It is one of the clearest places where “AC mechanics, not AC salesmen” shows up in practice, because the honest tonnage is sometimes smaller than what you have, and a company paid by the ton has no incentive to tell you that.
