Cooling · South Carolina
How Much Does It Cost to Run a Window Air Conditioner in South Carolina?
The short answer
A typical 900W window air conditioner costs about $0.14 per hour to run in South Carolina, or $33.88 a month at 8 hours a day.
South Carolina’s average residential rate was 15.5¢ per kWh in July 2026 (EIA), 16% below the US average.
Source: U.S. EIA, July 2026 data · Updated
Window Air Conditioner cost by daily use in South Carolina
| Daily use | kWh/month | Per day | Per month | Per year |
|---|---|---|---|---|
| 1 hour/day | 27.4 | $0.14 | $4.24 | $50.82 |
| 2 hours/day | 54.8 | $0.28 | $8.47 | $102 |
| 4 hours/day | 109.5 | $0.56 | $16.94 | $203 |
| 8 hours/day | 219.0 | $1.11 | $33.88 | $407 |
| 12 hours/day | 328.5 | $1.67 | $50.82 | $610 |
| 24 hours/day | 657.1 | $3.34 | $102 | $1,220 |
South Carolina vs other states
At typical use, a window air conditioner costs $407 a year in South Carolina — $855 less than in Hawaii and $72.27 more than in Louisiana.
South Carolina has the 20th-cheapest residential electricity of the 50 states and DC. electricity prices in South Carolina · all states ranked
Electricity price trend in South Carolina
15.5¢/kWh in July 2026 — ▲ +5.2% from a year earlier.
How to lower the cost of running a window air conditioner
Window air conditioners cool a single room and are far cheaper to run than central AC when you only need one or two rooms cool. Wattage scales with capacity: small 5,000 BTU units draw around 450–500W, a 10,000 BTU unit around 900W, and large 15,000+ BTU units 1,300–1,500W. ENERGY STAR models with inverter compressors can use 20–35% less. The compressor cycles with the thermostat, so enter the hours it actually runs.
- Pick the right size — an oversized unit cycles constantly and dehumidifies poorly.
- Seal the gaps around the unit with foam strips to keep hot air out.
- Clean the washable filter every two weeks in peak season.
- Long, hot summers in South Carolina mean cooling equipment can run most of the day from May through September — try 10–12 hours above to see a peak-month cost.
Questions
Frequently asked questions
How much does it cost to run a window air conditioner for 24 hours in South Carolina?
Running a 900W window air conditioner for 24 hours uses about 21.6 kWh, which costs about $3.34 at South Carolina’s average rate of 15.5¢/kWh.
How many kWh does a window air conditioner use per month?
At 8 hours a day, a typical window air conditioner uses about 219 kWh a month. In South Carolina that costs $33.88.
Is it expensive to run a window air conditioner in South Carolina?
South Carolina has the 20th-cheapest residential electricity of the 50 states and DC at 15.5¢/kWh — cheaper than most. Running a window air conditioner here costs about $407 a year at typical use, compared with $481 at the national average rate.
What is the electricity rate in South Carolina right now?
The average residential electricity rate in South Carolina was 15.5¢ per kWh in July 2026, according to the latest EIA data — up 5.2% from a year earlier.
Is a window AC cheaper to run than central air?
For cooling one or two rooms, yes. A 900W window unit uses about a quarter of the power of a typical 3,500W central system.
Window Air Conditioner costs in nearby states
Other appliances in South Carolina
Cheapest and priciest states
Comparisons
Sources & method
- Electricity rates: U.S. Energy Information Administration, Electric Power Monthly — average residential retail price, July 2026 (latest available). Retrieved .
- CO₂: EIA State Electricity Profiles, 2024 emissions rate of in-state power generation.
- Default usage for window air conditioner: 8 hours a day. Typical power 900W.
- Formulas, duty cycles and limitations: methodology. Data download: open data (CC BY 4.0).