Model
Lg LW1224IVSM
Rank #231 means 230 of the 404 room air conditioner models we track cost less to run each year; the 43rd efficiency percentile means it uses less energy for its size than 43% of those models.
What does the Lg LW1224IVSM cost to run per year?
Among the 404 room air conditioner models we track, the Lg LW1224IVSM's $111/yr running cost ranks it #231, close to dead center. It uses 38% less energy than the U.S. federal standard model in its class, which would cost about $180/yr to run, a saving of roughly $69 a year. Size-adjusted, this model sits close to the class median on efficiency, ahead of 43% of room air conditioner models we track. Its CEER of 15 reflects combined energy efficiency ratio, one of the class's core efficiency levers.
Immediately around it on the leaderboard, the Lg LW1222IVSM at $111/yr runs a little cheaper and the Midea 1014634874 at $111/yr runs a little more, a sense of how tightly models are packed at this point in the ranking. A room air conditioner typically stays in service for somewhere around 10 years; over that span, the Lg LW1224IVSM's $111/yr adds up to roughly $1110 in electricity alone, before purchase price or repairs.
Also sold as: Black+Decker BD12NWES.
By the numbers
The Lg LW1224IVSM normalized against its whole class, so each figure means something.
What it costs you over time
Running cost is an every-year number, so it compounds. At $111/yr, here is what the Lg LW1224IVSM adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Lg LW1224IVSM costs about $1110. That is roughly $690 less than a standard model in its class, which would run closer to $1800 over the same ten years.
How the Lg LW1224IVSM compares
The room air conditioner class we track runs from $51 to $389 a year. At $111/yr, it runs about $12 a year above the class median of $99, and it is about $60 a year more than the cheapest room air conditioner to run at $51. Against the US federal standard model for its class at about $180/yr, the Lg LW1224IVSM uses 38% less energy.
What drives its running cost
At 12000 BTU/hr, the Lg LW1224IVSM is a mid-size room air conditioner for its class, which spans 5000 to 34100 BTU/hr with a median of 10100 BTU/hr, neither the size advantage of a small unit nor the size penalty of a large one applies here, so its running cost is a fairer test of efficiency alone. The CEER of 15 on this model, above the class median of 15, measures combined energy efficiency ratio; it is the number to compare directly against another model's CEER if capacity is similar.
- Combined Energy Efficiency Ratio (CEER). Two units with the same BTU rating can post very different running costs, and CEER is the figure that explains most of that gap.
- BTU cooling capacity. BTU rating scales with room size, and it is usually the first driver of an air conditioner's running cost, ahead of its CEER figure.
- Thermostat and mode usage. How the unit is actually operated, thermostat cycling versus a fixed setting, moves real electricity use more than the rated BTU or CEER figure alone.
Common questions
Is the Lg LW1224IVSM cheap to run?
Roughly, yes. Its $111/yr figure is close to the class median, ranking #231 of 404, neither a bargain nor a splurge on running cost.
How much does the Lg LW1224IVSM cost per month?
About $9.28 a month, which is the $111 annual estimate spread across twelve months at the US average rate of $0.1856/kWh. Your own bill scales with your local electricity rate and how heavily you use it.
How is this running-cost figure calculated?
The formula is annual kWh times price per kWh: 600 kWh from ENERGY STAR times the US average of $0.1856/kWh comes to about $111 a year. It covers electricity only, not the purchase price, water, or installation.
How efficient is the Lg LW1224IVSM for its size?
43rd percentile once size is factored in, a fairly typical result for the class.
Cheaper to run in the same class
| Rank | Model | Cost/yr |
|---|---|---|
| 257 | Lg LW1222IVSM12000 BTU/hr | $111 |
| 256 | Ktaxon TIWC-12CRD112000 BTU/hr | $111 |
| 255 | Ktaxon KXTIW-12CRD112000 BTU/hr | $111 |
| 254 | Keystone KSTAW12INV12000 BTU/hr | $111 |
| 253 | Keystone KSTAW121WA12000 BTU/hr | $111 |
Source
ES_1118034_LW1224IVSM_11202023125113_80190901View certified room air conditioner listingsENERGY STAR data as of July 2026Lg and LW1224IVSM are used here for identification only and are not endorsements. Figures are computed by WattWise Labs from public ENERGY STAR data, not measured in our own lab.