AC vs heat pump
Cooling capacity is only one season. Check winter output before comparing nominal tons.
| Question | Central AC | Heat pump |
|---|---|---|
| Main task | Cooling and humidity removal; heating is supplied separately. | Cooling plus heating, with performance changing in cold weather. |
| Sizing input | Summer building load, airflow and manufacturer cooling data. | Both seasonal loads, winter capacity curve and backup strategy. |
| Why nominal tons differ | Tons describe rated cooling capacity, not electrical input. | A winter heating-led selection can be larger than a cooling-only screen. |
| Comfort check | Avoid short cycling and poor humidity control. | Check minimum summer output, modulation and zoning. |
| Professional decision | Manual J loads, Manual S selection and Manual D ducts. | The same process plus design-temperature performance, defrost and balance temperature. |
Bring the actual inputs.
Compare bids that identify the measured demand, the exact model, operating conditions and installation requirements. A headline capacity or broad household average is not enough to choose equipment.
Planning estimate. A licensed contractor must confirm final size and installation. Electrical work needs a licensed electrician.
Sources and methods.
Read the model methods and assumptions and primary source register. The linked calculators show their working and relevant sources for your selected inputs.