
WindowENERGY STAR
LG LW1521ERSM 15,000 BTU
Cooling
15,000 BTU
Covers
800 ft²
Efficiency
11.8 CEER
Noise
53 dB
$549 est.
typical retail priceLG's dual-inverter scaled to whole-floor duty — 14,000 BTU across 800 sq ft, still hitting 44 dB in sleep mode.
Estimated from this unit's 14.7 CEER rating at 8 hours/day of cooling, using average residential electricity rates for each US climate zone. Your usage and utility rate will shift these numbers — run the calculator for your exact room.
| Climate zone | Example regions | Est. cost / month |
|---|---|---|
| Cool North | Pacific NW, Upper Midwest, New England | $37 /mo |
| Mixed / Temperate | Mid-Atlantic, Midwest, Mountain | $39 /mo |
| Hot & Humid | Southeast, Gulf Coast, Texas | $32 /mo |
| Hot & Dry | Southwest, Desert | $34 /mo |
| Type | Window air conditioner |
| Cooling capacity | 14,000 BTU |
| Rated coverage | 800 ft² |
| Efficiency | 14.7 CEER |
| Noise (low) | 44 dB |
| Smart features | App, Voice |
| ENERGY STAR | Yes |
| Model number | LW1522IVSM |
| Typical street price | $529 |
Specs from manufacturer data; price and ratings are snapshots and may vary. See how we evaluate. Data last reviewed June 2026.


