Model
Lg LW1822IVSM
Rank #362 means 361 of the 404 room air conditioner models we track cost less to run each year; the 13th efficiency percentile means it uses less energy for its size than 13% of those models.
What does the Lg LW1822IVSM cost to run per year?
The Lg LW1822IVSM holds rank #362 of 404 on running cost, at about $170 a year, a genuinely pricey result for the class. It uses 37% less energy than the U.S. federal standard model in its class, which would cost about $270/yr to run, a saving of roughly $100 a year. Its size-adjusted efficiency percentile of 13 means the low running cost, where it exists, is driven almost entirely by capacity rather than efficiency. The CEER figure of 14.7 on this model captures combined energy efficiency ratio, the main efficiency lever ENERGY STAR tracks for this class.
Immediately around it on the leaderboard, the Midea MWCUWH-18CRFN8-MCN10 at $167/yr runs a little cheaper and the Friedrich CCV18A30A at $174/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 LW1822IVSM's $170/yr adds up to roughly $1700 in electricity alone, before purchase price or repairs.
By the numbers
The Lg LW1822IVSM 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 $170/yr, here is what the Lg LW1822IVSM 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 LW1822IVSM costs about $1700. That is roughly $1000 less than a standard model in its class, which would run closer to $2700 over the same ten years.
How the Lg LW1822IVSM compares
The room air conditioner class we track runs from $51 to $389 a year. At $170/yr, it runs about $71 a year above the class median of $99, and it is about $119 a year more than the cheapest room air conditioner to run at $51. Against the US federal standard model for its class at about $270/yr, the Lg LW1822IVSM uses 37% less energy.
What drives its running cost
At 18000 BTU/hr, the Lg LW1822IVSM is a large room air conditioner for its class, which spans 5000 to 34100 BTU/hr with a median of 10100 BTU/hr, size is usually the single biggest lever behind a running-cost figure, and at this end of the range there is more capacity to service, which tends to push the number up. Beyond size, its CEER of 14.7, below the class median of 15, is the class's own efficiency yardstick, combined energy efficiency ratio, and it is what separates two similarly sized models with different running costs.
- 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 LW1822IVSM cheap to run?
Its $170/yr running cost, rank #362 of 404, is above what most room air conditioner models we track cost to run, so this is not one of the cheaper picks on electricity alone.
How much does the Lg LW1822IVSM cost per month?
About $14.2 a month, which is the $170 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: 918 kWh from ENERGY STAR times the US average of $0.1856/kWh comes to about $170 a year. It covers electricity only, not the purchase price, water, or installation.
How efficient is the Lg LW1822IVSM for its size?
13th percentile once size is factored in. That means its size-adjusted efficiency is not the main reason for the running-cost figure above; its capacity plays a large role too.
Cheaper to run in the same class
Source
ES_1118034_LW1822IVSM_09222023104627_80182318View certified room air conditioner listingsENERGY STAR data as of July 2026Lg and LW1822IVSM 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.