For full system planning, use the WattSizing Calculator.
Quick Answer
In summer, central AC systems often run at 2,000-5,500 W with 15-45 kWh/day depending on tonnage and climate.
Detailed Explanation
Summer afternoons push compressor duty cycle up and increase whole-home cooling demand. See How Many Watts Does a Central Air Conditioner Use and How to Calculate Daily Energy Use.
Watt Table
| System Size | Running Watts | Summer kWh/day |
|---|---|---|
| 2 ton | 2,000 - 3,000 W | 15 - 25 |
| 3 ton | 2,800 - 4,000 W | 20 - 32 |
| 4 ton | 3,500 - 5,000 W | 28 - 40 |
| 5 ton | 4,200 - 5,500 W | 32 - 45 |
Calculation Example
3,500 W x 8 h/day = 28 kWh/day.
Tips
- Change filters regularly.
- Reduce attic heat gain and leaks.
- Pre-cool before late-afternoon peak.
- Keep supply/return vents unobstructed.
FAQs
Why is summer cost disproportionately high?
High runtime plus high outdoor temperature.
Does variable-speed central AC help?
Yes, especially during partial-load hours.
Is duct leakage important?
Yes, it can add major hidden load.
CTA
Estimate full-home cooling demand with the WattSizing Calculator.
