Where the Ton Came From
Air conditioning capacity is measured in tons, and the word has nothing to do with what the equipment weighs. One ton of cooling means the system can remove 12,000 BTU of heat per hour. The term is a souvenir from the ice trade: melting one ton of ice over 24 hours absorbs heat at almost exactly that rate, so when mechanical refrigeration started replacing ice deliveries, the new machines were rated against the blocks they displaced. The wagons are long gone. The unit stuck.
Residential systems run from 1.5 to 5 tons, usually in half-ton steps. You’ll also see the same capacity written in BTU on spec sheets; a 36,000 BTU unit is a 3-ton unit in different clothes. Past 5 tons, a home usually gets a second system rather than one giant unit.
How Many Tons Your House Needs
In South Louisiana we figure roughly 480 to 500 square feet per ton as a starting point. A 1,500 square foot home lands near 3 tons, and 2,400 square feet points toward 5. Treat that as the opening estimate, not the answer. Tall ceilings add air volume the square footage doesn’t show. A thin attic blanket, big west-facing windows, and a full house of people all push the load up, while deep shade and tight construction pull it down.
That’s also why a size quoted over the phone from square footage alone is a guess. Our AC sizing calculator runs those adjustments against your actual house, and a proper in-home load calculation confirms the number before anything gets installed.
Bigger Isn’t Better, and Smaller Isn’t Either
An oversized system cools the air in a hurry, satisfies the thermostat, and shuts down. Those short cycles never run long enough to wring moisture out of the air, and along the Gulf, moisture removal is half of what an air conditioner is for. You get a house that reads 72 on the wall and feels clammy anyway. All that extra starting and stopping is also the roughest duty a compressor can pull.
Undersizing fails the opposite way. The system grinds through an August afternoon without ever catching up, piling on run hours and electricity while the house sits a few degrees above the setpoint. A right-sized system splits the difference: long, steady cycles that hold both the temperature and the humidity where you set them. Neither mistake is cheap to live with, which is why sizing gets settled before anybody talks equipment.
From Tonnage to a Real Number
Tonnage is also the first thing that sets the price of a replacement, which is why our price tables list systems by size. Once you know your tonnage, you can see what every tier of equipment looks like for a house like yours. So start with the calculator, look up your size in the tables, and when you want it confirmed, our AC installation team measures the house in person before we put a firm quote on paper. Want to talk it through first? Call us at (337) 893-5646.