What the tool actually does
This site starts at 22 BTU per square foot, then nudges for sun, envelope, ceiling, and stories. We round to the nearest half-ton because that is how residential equipment is sold. The range under the headline is about ±10%.
A mixed-sun average 1,800–2,000 sq ft one-story house often prints about 3.5 tons. Plenty of tight or shaded houses in that size sit nearer 3. That is the argument. It is not a reason to install 4 “to be safe.”
It depends on the house. The ~3.5 tons above is a rule of thumb, not your answer. A typical Orlando 2,000 sq ft house can come out closer to 2.5 tons once you enter windows, insulation, ducts, and orientation in the calculator’s “Refine for your house” section. Before you buy, always get a load calculation (Manual J) from a licensed HVAC professional.
When 3 tons is the better Florida call
- Manual J latent and sensible loads fit a 3-ton match with honest airflow.
- The house is tighter, shaded, or two-story with less roof per square foot.
- The old 3.5 or 4-ton unit short-cycles and the rooms feel clammy at 74.
When 3.5 tons is honest
- West glass, a hot attic, leaky ducts, or a leaky 1970s envelope push the load up.
- The Manual J number is closer to 3.5 than 3 after real window and duct inputs.
Do not buy either size from this page. Take the range to a contractor and ask to see the load calc. Wrong tonnage is expensive to undo.
Run the 2,000 sq ft example · 2,000 sq ft walkthrough
Common questions
Should I pick 3 tons or 3.5 tons in Florida?
If you land between two sizes, the smaller one usually dehumidifies better here. Runtime is what dries the air. Confirm with a Manual J load calc before you buy either size.
Why can a bigger AC feel clammy?
A bigger “just in case” box cools the thermostat and quits before the coil wrings the house out. An oversized unit short-cycles and rooms can feel clammy at 74.
When is 3.5 tons the honest size?
When west glass, a hot attic, leaky ducts, or a leaky 1970s envelope push the load up, and the Manual J number is closer to 3.5 than 3 after real window and duct inputs.
Should I install 4 tons to be safe?
No. Wrong tonnage is expensive to undo. Take the range to a contractor and ask to see the load calc.