Mini-splitENERGY STAR
Senville LETO SENL-12CD
Cooling
12,000 BTU
Covers
550 ft²
Efficiency
21.2 SEER2
Noise
28 dB
$799 est.
typical retail priceHot & Humid · ~14¢/kWh · 7-month season
Air conditioning in South Carolina: sizing, costs & the right units
Charleston and the Lowcountry combine Gulf-grade humidity with coastal salt air; the Upstate runs slightly milder. South Carolina summers are long and damp, with cooling from late April through October on the coast.
Updated June 2026
What to look for in South Carolina
Coastal buyers should treat corrosion protection as a primary spec — coated coils and stainless hardware extend life dramatically within a few miles of salt water. Inland, standard humid-climate rules apply: inverter drive, right-sizing, and strong dehumidification.
What cooling costs in South Carolina
Estimated at South Carolina's average residential rate (~14¢/kWh, approximate) and 8 hours/day. "Per season" assumes 7 cooling months. Your utility rate and usage will vary.
| Unit | Efficiency | Est. / month | Est. / season |
|---|---|---|---|
| Senville LETO SENL-12CD Mini-split | 21.2SEER2 | $23 | $161 |
| LG Dual Inverter LW1022IVSM Window | 15CEER | $23 | $161 |
| BLACK+DECKER BPACT14WT Portable | 6.1CEER | $80 | $560 |
Climate-matched
All 58 units Units that fit South Carolina's climate
Editor's pick
WindowENERGY STAR
LG Dual Inverter LW1022IVSM
Cooling
10,000 BTU
Covers
450 ft²
Efficiency
15 CEER
Noise
44 dB
$429 est.
typical retail price
Best portable
Portable
Midea Duo MAP12S1TBL-A
Cooling
12,000 BTU
Covers
450 ft²
Efficiency
14.7 CEER
Noise
42 dB
$579 est.
typical retail priceSouth Carolina AC questions, answered
What should Charleston-area buyers look for in an AC?
Salt-air resilience: coated condenser coils, sealed electronics, and a willingness to rinse the outdoor coil monthly in season. Mini-split outdoor units generally weather coastal exposure better than bare window-unit chassis.
How many BTU do I need in South Carolina?
Hot & Humid zone rules: 10–15% above baseline. A 400 ft² Lowcountry living area typically needs 10,000–12,000 BTU; shaded Upstate rooms can size toward the lower bound.
What does cooling cost in South Carolina?
At ~14.5¢/kWh and 8 hours/day, an efficient 10–12K unit runs about $24–34/month across a 7-month season. ENERGY STAR inverter units typically save $50–90/year versus older fixed-speed units here.
Electricity rates are approximate state averages; check your utility bill for your exact rate.