Question 1

How many square feet does one ton of cooling cover?

Accepted Answer

Rough rule for moderate climates: 500-600 sq ft per ton in a well-insulated 1990s+ home, 400-500 sq ft per ton in older homes with less insulation. Hot climates (TX, AZ, FL) trend lower — 350-450 sq ft per ton. This estimator covers those bands by climate zone, but always run a Manual J for design submission.

Question 2

Why can't I just match the existing equipment size?

Accepted Answer

The original sizing may have been wrong, the home's insulation may have been improved, or the duct system may have been changed. Oversized A/C short-cycles (poor humidity removal, premature failure), undersized can't keep up on design days. Spend 20 minutes on a load calculation before signing the replacement quote — the savings on a one-size-down unit often pays for the calc itself.

Question 3

What about humidity in southern climates?

Accepted Answer

In FL, GA, AL, MS, LA, and coastal TX, latent (humidity) load can equal or exceed sensible (temperature) load. A 2-ton unit on a 1,400 sq ft Florida home may keep the temperature at 75°F but leave humidity at 65%. Consider variable-speed equipment or a dedicated dehumidifier as part of the design — the capacity number alone is not the full answer.

Question 4

Does this estimator account for windows or ceiling height?

Accepted Answer

No — it's a ballpark first-pass tool. Windows, ceiling height, shading, occupancy, and air infiltration all affect load by 10-30%. Use this estimator to set buyer expectations, but always run a Manual J or BlockLoad calc on equipment sales over $5K. The hvac_design_studio on loadcalc.launchmyhvac.com handles full Manual J.

Question 5

What climate zone does my city fall in?

Accepted Answer

IECC climate zones: Zone 1 = very hot (Miami, Honolulu). Zone 2 = hot/humid (Houston, Phoenix, Orlando). Zone 3 = warm (Atlanta, Memphis, Las Vegas). Zone 4 = mixed (Nashville, St. Louis, DC). Zone 5 = cool (Chicago, Denver, Indianapolis). Zone 6 = cold (Minneapolis, Burlington). Zone 7 = very cold (Duluth, Anchorage). Pick the closest match for the climate dropdown.

Equipment Capacity Estimator

Inputs

⚠️ This is design-assist only

Equipment Capacity Estimator

Inputs

⚠️ This is design-assist only

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