Disclaimer

The calculators and content on ClimateCalcs.com are provided for general information and planning.

Estimates, not guarantees

Results are deterministic estimates from your inputs and standard reference constants (1 ton = 12,000 BTU/h, 400 CFM/ton, climate-zone BTU/sq-ft bands, energy contents, DOE 2023 SEER2/HSPF2 basis, ASHRAE 62.2 rates). Real homes vary — verify a figure before relying on it.

Sizing accuracy

Rule-of-thumb sizing is a starting estimate, not a substitute for a professional Manual J / Manual S load calculation. Bigger is not better: an oversized system short-cycles, controls humidity poorly and wastes energy. Have a pro run a load calc before buying equipment.

Gas, electrical & refrigerant work

Gas appliances must be installed and serviced by a licensed professional — improper work risks fire and carbon-monoxide poisoning; install CO alarms. Handling refrigerant requires EPA Section 608 certification — DIY charging is illegal and dangerous.

No professional, financial or engineering advice

Nothing here is professional HVAC, construction, engineering, financial or safety advice; cost tools give estimates, not bids, and the financing tool is illustrative, not a loan offer. Tax-credit amounts (IRA 25C / ENERGY STAR / DSIRE) change — confirm current details with the IRS and ENERGY STAR. For sizing, installation, permitting or persistent problems, consult a qualified professional.