How many square feet does the LG LW1224IVSM cool?

At 12,000 BTU/h it suits a room of about 450 to 550 sq ft with normal sun and two people, following the ENERGY STAR sizing guide. In a heavily shaded room that stretches to about 495-605 sq ft; in a very sunny one it shrinks to 405-495 sq ft. A kitchen needs 4,000 BTU more.

How many watts and amps does the LG LW1224IVSM use?

About 800 watts at full power (12,000 BTU/h divided by its CEER of 15.0), which is 7.0 amps at 115 V. That is 0 W less than the typical unit in its class (800 W), or $0 a year cheaper to run at 18.0¢/kWh. Its inverter compressor slows down instead of cycling, so real use is usually lower. Its CEER beats 18% of the 34 units in the class.

Can the LG LW1224IVSM run on a standard outlet?

Yes. It runs on 115 V and draws about 7.0 A, well inside a standard 15 A outlet, but do not share the circuit with a space heater, microwave or other big load. 12% of certified units in this class need 230 V, so a 115 V model is the easy case.

What are the dimensions of the LG LW1224IVSM, and will it fit my window?

23.6" W × 15" H × 28.8" D, 85 lb. It is narrower than 27% of its 33 competitors and lighter than 21% of them. The window must be wider than 23.6"; the side panels fill the remaining gap.

Can the LG LW1224IVSM also heat the room?

No, it only cools. If you also need heat, 5 certified units in this class can do both; see the list of air conditioners with heat.

Is the LG LW1224IVSM worth buying to replace an old air conditioner?

An old unit of the same size at 9 CEER would cost about $180 a year to run at 750 hours and 18.0¢/kWh; this one costs about $108, so it saves roughly $72 a year.

12,000 BTU window air conditioner

LG LW1224IVSM

Below average efficiency for its size: a CEER of 15.0 ranks #22 of 34 12,000 BTU window air conditioners.

It cools a room of about 450-550 sq ft, draws about 800 watts and costs about $108 a year to run at typical U.S. use and prices.

CEER: 15.0 Combined efficiency, higher is better
Below average · beats 38%
Cooling: 12,000 BTU/hFor about 450-550 sq ft
Energy use: 600 kWh/yr38% less than the federal minimum
Unit size: 23.6" wide 15" high, 28.8" deep, 85 lb

A good fit if…

You want to plug it into an ordinary outlet - it runs on 115 V.

Think twice if…

Running cost matters most - its CEER is below average for 12,000 BTU window air conditioners.
You plan to install it alone - at 85 lb it is a two-person job.
You also need heat - it cools only.

Calculate my running cost Check the size for my room

Details

Specifications12,000 BTU, 115 V

General
Brand	LG
Model number	LW1224IVSM
Type	Window
Design	Standard box
Heating	No, cooling only
Compressor	Variable speed (inverter)
Voltage	115 V (standard outlet)
Refrigerant	R-32 (GWP 675)
Support bracket included	Yes
On the market since	November 1, 2023
Last certified	November 1, 2023
Performance
Cooling capacity	12,000 BTU/h
CEERCombined energy efficiency ratio, includes standby power	15.0
Yearly energy useENERGY STAR test: 750 hours	600 kWh
Better than federal minimum	38% less energy
ENERGY STAR Most Efficient	No
Size
Width × height × depth	23.6" W × 15" H × 28.8" D
Weight	85 lb

How it compares with 33 other 12,000 BTU window units#22 of 34

CEER (class median 15.0)15.0, tied with 13 others
Yearly cost vs. class median ($108)about the same
Width 23.6" (class median 20.3")narrower than 27%
Weight 85 lb (class median 59 lb)lighter than 21%
Rank among 13 similar designs#10

Compared with the other ENERGY STAR certified 12,000 BTU window units. Yearly cost at 750 hours and 18.0¢/kWh.

Questions6

How many square feet does the LG LW1224IVSM cool?: At 12,000 BTU/h it suits a room of about 450 to 550 sq ft with normal sun and two people, following the ENERGY STAR sizing guide. In a heavily shaded room that stretches to about 495-605 sq ft; in a very sunny one it shrinks to 405-495 sq ft. A kitchen needs 4,000 BTU more.
How many watts and amps does the LG LW1224IVSM use?: About 800 watts at full power (12,000 BTU/h divided by its CEER of 15.0), which is 7.0 amps at 115 V. That is 0 W less than the typical unit in its class (800 W), or $0 a year cheaper to run at 18.0¢/kWh. Its inverter compressor slows down instead of cycling, so real use is usually lower. Its CEER beats 18% of the 34 units in the class.
Can the LG LW1224IVSM run on a standard outlet?: Yes. It runs on 115 V and draws about 7.0 A, well inside a standard 15 A outlet, but do not share the circuit with a space heater, microwave or other big load. 12% of certified units in this class need 230 V, so a 115 V model is the easy case.
What are the dimensions of the LG LW1224IVSM, and will it fit my window?: 23.6" W × 15" H × 28.8" D, 85 lb. It is narrower than 27% of its 33 competitors and lighter than 21% of them. The window must be wider than 23.6"; the side panels fill the remaining gap.
Can the LG LW1224IVSM also heat the room?: No, it only cools. If you also need heat, 5 certified units in this class can do both; see the list of air conditioners with heat.
Is the LG LW1224IVSM worth buying to replace an old air conditioner?: An old unit of the same size at 9 CEER would cost about $180 a year to run at 750 hours and 18.0¢/kWh; this one costs about $108, so it saves roughly $72 a year.

Running cost calculator

Pre-filled with this model. Pick your state and how many hours you run it, or see the yearly cost in every state.

1. The air conditioner LG LW1224IVSM

Cooling capacity BTU/hCEER efficiency, higher is better

2. How you use it

StateElectricity ¢ per kWhHours a day at full powerDays a year from your state's climate

Per year: $169
Per month of use: $31
Per day: $1.02
Per hour: 12.8¢
Power draw: 800 W

Electricity used: 1,056 kWh a yearAn old 9 CEER unit of the same size would cost $282

Power draw is capacity divided by CEER, which already includes standby power. Inverter units often run below full power, so real use can be lower. Electricity prices: U.S. EIA residential averages (12 months to July 2026). Days a year start from your state's cooling degree days (NOAA 1991-2020 normals).

Closest alternatives

Units with a similar CEER in the same class, and what sets each one apart from the LG LW1224IVSM.

Model	CEER	Compared with this one
Whirlpool WHAW-121IN	15.0	same CEER, 0.6" wider, 20 lb lighter, U-shaped
TCL H12W4MW	15.0	same CEER, 0.6" narrower, 26 lb lighter
TCL T12WQ2S	15.0	same CEER, 2.9" narrower, 26 lb lighter, U-shaped
Hisense LWCT12W25A	15.0	same CEER, 3.3" narrower, 30 lb lighter, U-shaped
Danby DAC120ECBIWDB	15.0	same CEER, 1.9" narrower, 34 lb lighter

See all 34 12,000 BTU window air conditioners, ranked

Source: ENERGY STAR Certified Room Air Conditioners (U.S. EPA), certification of November 1, 2023. How we use the data.