About these Florida HVAC tools
Planning calculators for homeowners and techs. Florida humidity first. Not a contractor. Not a quote. Not Manual J.
tonnagecalc.com is a small set of DIY Florida HVAC tools. The tonnage page is one calculator: square feet and city give an instant rule-of-thumb answer (about 22 BTU per square foot), and “Refine for your house” swaps in a house-specific load using Florida city design weather, windows, walls, attic insulation, ducts, and air leakage, with every line of the math shown. The two numbers can differ by a ton or more, because sizing depends on the house. The other pages cover SEER2 cooling cost, monthly maintenance, refrigerants, repair versus replace, a freeze thaw list, and whole-home dehumidifier pints.
Written and maintained by an anonymous Florida HVAC field tech who works on residential systems in Florida heat and humidity every day. The author stays anonymous on purpose: there is no shop to sell you and no phone number to call. Every number on these pages is tied to a public source (manufacturers, ENERGY STAR, EPA, DOE, FPL, NOAA) listed on the page. Last reviewed 13 October 2026. The site is written for Florida houses, with a Central Florida default on the region toggle. South and North Florida are one click away. The 22 BTU formula does not change when you switch regions.
There is no shop on this domain, no booking form, and no contractor phone number. These pages are free planning tools. Google AdSense may show ads. There is no contractor phone and no booking form.
Contact: hello@tonnagecalc.com
Tools
Common questions
Is tonnagecalc.com a contractor?
No. It is a small set of free DIY Florida HVAC planning tools built by an independent Florida tech. There is no shop, no booking form, and no contractor phone number.
How does the tonnage calculator estimate size?
It is a rule-of-thumb estimator at about 22 BTU per square foot, adjusted for sun, envelope, ceiling height, and stories. It is not a quote and not Manual J.
Does the Florida region toggle change the formula?
No. Central Florida is the default and South and North Florida are one click away, but the 22 BTU formula does not change when you switch regions.
How do I contact the site?
Email hello@tonnagecalc.com.