Quick answer: size the unit to the room using Energy Star’s chart [1], then pick an Energy Star certified model with a high CEER . Every pick below is on Energy Star’s certified list, and two of the four carry the extra Most Efficient designation [2]. Before you buy, check the model against CPSC recalls: two big window-unit recalls in 2025 and 2026 are left off this list [9][10].
At a glance
- Sizing rule
- About 6,000 BTU for 150 to 250 sq ft; 10,000 BTU for 400 to 450 sq ft [1]
- Sunny room
- Add 10% capacity; heavily shaded, subtract 10% [1]
- Kitchen
- Add 4,000 BTU [1]
- Oversizing
- Costs more, wastes energy, doesn't cool better [1]
- Most Efficient
- Top Energy Star tier; Energy Star says these units are also low noise [1]
How we chose
We didn’t test these air conditioners. We picked them from Energy Star’s certified room air conditioner data, makers’ product pages and CPSC’s recall list:
- Energy Star certified. Every model is on Energy Star’s list of certified room air conditioners, and we give its CEER, its estimated yearly energy use and how much less energy it uses than the federal standard, as Energy Star lists them [2]. Energy Star sets minimum CEER levels by size and type of unit [3].
- A variable-speed compressor . Every pick has one, per Energy Star’s data [2], and Energy Star says variable-speed models are much more efficient than on/off ones [1].
- Recall check. We searched CPSC’s recall database for window air conditioners and for each brand on November 6, 2026 [7]. We left out Midea’s U-shaped units and Friedrich’s Kühl line because of the recalls below.
The picks
Best for: A small bedroom or home office
LG 6,000 BTU Dual Inverter Smart Window AC (LW6023IVSM)
LG rates it for up to 250 square feet and as quiet as 44 dB [4]. It's one of the most efficient small units on Energy Star's list, with a Most Efficient designation and an estimated 290 kWh a year [2].
- 6,000 BTU; cools up to 250 sq ft, per LG [4]
- CEER 15.5; 41% less energy than the federal standard [2]
- Energy Star Most Efficient; variable-speed compressor [2]
- Wi-Fi with LG ThinQ app; works with Google Assistant and Alexa [4]
Safety check: Energy Star certified. No CPSC recall found for LG window air conditioners (checked 2026-11-06).
Watch out: LG's page doesn't list window-size limits, so check the installation manual against your window before you order.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: A medium room you want to control from your phone
LG 10,000 BTU Dual Inverter Smart Window AC (LW1022IVSM)
LG rates it for up to 450 square feet and as quiet as 44 dB, with Wi-Fi control through the LG ThinQ app [5]. Energy Star lists it as straddling the windowsill and coming with a support bracket [2].
- 10,000 BTU; cools up to 450 sq ft, per LG [5]
- CEER 15; 38% less energy than the federal standard [2]
- About 500 kWh a year, per Energy Star [2]
- Wi-Fi with LG ThinQ app [5]
- Support bracket included; 63 lb [2]
Safety check: Energy Star certified. No CPSC recall found for LG window air conditioners (checked 2026-11-06).
Watch out: It isn't a Most Efficient model, and at 63 lb it's a two-person installation [2].
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: An open-plan space over 1,000 sq ft
LG 23,500 BTU Dual Inverter Smart Window AC (LW2422IVSM)
LG rates it for up to 1,450 square feet [6]. Energy Star lists it as Most Efficient, using 54% less energy than the federal standard for its size [2].
- 23,500 BTU; cools up to 1,450 sq ft, per LG [6]
- CEER 14.5; 54% less energy than the federal standard [2]
- About 1,216 kWh a year, per Energy Star [2]
- Energy Star listings for 230-volt and 208-volt power [2]
- Wi-Fi; works with Google Assistant and Alexa [6]
Safety check: Energy Star certified. No CPSC recall found for LG window air conditioners (checked 2026-11-06).
Watch out: It runs on 208 or 230 volts, not a standard household outlet, and Energy Star lists it at 112 lb [2]. Plan the circuit and the lift before you buy.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: Cooling in summer and some heat in spring and fall
GE Energy Star 8,000 BTU Heat/Cool Window AC with Heat Pump (AWGP08W series)
It's an Energy Star certified window unit that also heats with a heat pump, rated by GE for rooms up to 350 square feet, with Wi-Fi control through the SmartHQ app [8]. Energy Star lists the AWGP08W family with heating mode and 35% less energy use than the federal standard [2].
- 8,000 BTU cooling; heat pump heating [8]
- Up to 350 sq ft, per GE [8]
- CEER 13.2; 35% less energy than the federal standard [2]
- Wi-Fi through SmartHQ; works with Alexa and Google Assistant [8]
- 45.2 lb [2]
Safety check: Energy Star certified. No CPSC recall found for GE window air conditioners (checked 2026-11-06).
Watch out: GE's page lists the AWGP08WWA version as no longer manufactured [8]. Energy Star's listing covers the AWGP08W model family [2], so match the full model number on the box to Energy Star's list.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Compare the picks
| Model | BTU | CEER | Less energy than federal standard | Est. kWh per year | Most Efficient |
|---|---|---|---|---|---|
| LG LW6023IVSM | 6,000 | 15.5 | 41% | 290 | Yes |
| GE AWGP08W (heat pump) | 8,000 | 13.2 | 35% | 455 | No |
| LG LW1022IVSM | 10,000 | 15 | 38% | 500 | No |
| LG LW2422IVSM (230V) | 23,500 | 14.5 | 54% | 1,216 | Yes |
Recalls we left off the list
Sizing and setup tips
- Measure the room, then use Energy Star’s chart, which assumes an 8-foot ceiling [1]. Adjust for sun, a kitchen, and each regular occupant beyond two (add 600 BTU each) [1].
- Don’t round way up. Energy Star says an oversized unit wastes energy and doesn’t cool better [1].
- Mind the corner. If the unit will sit near a corner of the room, Energy Star says to pick one whose airflow can be directed properly [1].
Sources
- Energy Star: Room Air Conditioners (sizing chart and buying guidance)
- Energy Star: Certified Room Air Conditioners (product finder data)
- Energy Star: Room Air Conditioners Key Product Criteria
- LG: LW6023IVSM 6,000 BTU Dual Inverter Window AC product page
- LG: LW1022IVSM 10,000 BTU Dual Inverter Window AC product page
- LG: LW2422IVSM 23,500 BTU Dual Inverter Window AC product page
- U.S. Consumer Product Safety Commission: Recalls
- GE Appliances: Energy Star 8,000 BTU Smart Heat/Cool Window Air Conditioner with Heat Pump (AWGP08WWA)
- CPSC: Midea Recalls About 1.7 Million U and U+ Window Air Conditioners Due to Risk of Mold Exposure (June 2025)
- CPSC: Friedrich Air Conditioning Recalls KÜHL Window Air Conditioners (Sept. 2026)
Common questions
What size window air conditioner do I need?
Energy Star's sizing chart starts at 5,000 BTU for 100 to 150 square feet and reaches 12,000 BTU at 450 to 550 square feet, assuming an 8-foot ceiling. Add 10% for a very sunny room, 4,000 BTU for a kitchen and 600 BTU for each regular occupant beyond two.
Is a bigger air conditioner better?
No. Energy Star says an oversized unit costs more to buy, wastes energy and doesn't cool any better. Size it to the room.
What does Energy Star Most Efficient mean?
It's an extra Energy Star designation for the most efficient certified products of the year. Energy Star says Most Efficient room air conditioners are also low noise.
How do I know if my window air conditioner was recalled?
Find the model number on the unit's label and search it on CPSC's recall site. In 2025 Midea recalled about 1.7 million U-shaped window units sold under several brand names because of a mold risk, and in 2026 Friedrich recalled some Kühl window units for a fire hazard.