Best window air conditioners compared (2026)

A window air conditioner is usually the simplest way to cool a bedroom or living room properly, and in a heat wave that can matter for health: CDC says electric fans might provide some comfort, but when temperatures are really hot they won't prevent heat-related illness. This page compares window units by size, from a 5,000 BTU unit for a small bedroom to 12,000 BTU for a big room, and says which are inverters, which heat as well, and how each fits the window. Room sizes are the makers'. We haven't tested them ourselves.

By Tom Calder · Updated November 9, 2026 · 7 products, 5 of 7 price-tracked

Window air conditioners compared for US households

Our picks

Best mid-size window AC 4.5

8,000 to 10,000 BTU

Photo: Amazon

Midea U 8,000 BTU

8,000 BTU · 350 sq ft · Yes · U-shaped, window stays openable (22-36 in wide, 13.75 in min height)

A medium bedroom where you want to keep the window usable

Researched

$399.99 at Amazon

as of Nov 9, 2026, 11:40 AM ET · Details

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.

In stock

Check price →

Best for a small room 4.4

Under 8,000 BTU

Photo: Amazon

Midea U 6,000 BTU

6,000 BTU · 250 sq ft · Yes · U-shaped, window stays openable (22-36 in wide, 13.75 in min height)

A small bedroom where you want to keep the window usable

Researched

$314.99 at Amazon

as of Nov 9, 2026, 11:40 AM ET · Details

In stock

Check price →

Best for a large room 4.5

Over 10,000 BTU

Midea U 12,000 BTU

12,000 BTU · 550 sq ft · Yes · U-shaped, window stays openable (22-36 in wide, 13.75 in min height)

A large room where you want to keep the window usable

Researched

Check price →

All 7 compared

Show

Air conditioner	Cooling	Room size (maker)	CEER	Inverter	Heating	Install	Price
1. Midea 8,000 BTU U-Shaped Smart Inverter Window Air Conditioner Best mid-size window AC 8,000 BTU · 350 sq ft · Yes · U-shaped, window stays openable (22-36 in wide, 13.75 in min height) A medium bedroom where you want to keep the window usable 4.5	8,000 BTU	350 sq ft	—	Yes	—	U-shaped, window stays openable (22-36 in wide, 13.75 in min height)	$399.99 at Amazon as of Nov 9, 2026, 11:40 AM ET · Details Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. In stockCheck price →
Our verdict Our verdictResearched An 8,000 BTU U-shaped inverter model rated by Midea for 350 sq ft, with 710 W cooling watts listed. Like the rest of the U line, it leaves the window openable. The listing doesn't state a CEER. Best for A medium bedroom where you want to keep the window usable Good Window can still open Inverter, quiet operation Wi-Fi and voice control Worth knowing CEER not stated on the listing No heat mode listed Who shouldn't buy it: Don't buy it if you need heat in the shoulder seasons; look at the 8,000 BTU model with heat.
2. Midea 10,000 BTU U-Shaped Smart Inverter Window Air Conditioner 10,000 BTU · 450 sq ft · Yes · U-shaped, window stays openable (22-36 in wide, 13.75 in min height) A larger bedroom or living room with a standard window 4.5	10,000 BTU	450 sq ft	—	Yes	—	U-shaped, window stays openable (22-36 in wide, 13.75 in min height)	$399.99 at Amazon as of Nov 9, 2026, 11:40 AM ET · Details Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. In stockCheck price →
Our verdict Our verdictResearched A 10,000 BTU U-shaped inverter unit for rooms up to 450 sq ft by Midea's figure. It keeps the window openable and adds app and voice control. The listing doesn't state a CEER or heat mode. Best for A larger bedroom or living room with a standard window Good Window can still open Inverter, quiet operation Wi-Fi and voice control Worth knowing CEER not stated on the listing Needs a double- or single-hung window Who shouldn't buy it: Don't buy it if you have a casement or sliding window.
3. Midea 12,000 BTU U-Shaped Smart Inverter Window Air Conditioner Best for a large room 12,000 BTU · 550 sq ft · Yes · U-shaped, window stays openable (22-36 in wide, 13.75 in min height) A large room where you want to keep the window usable 4.5	12,000 BTU	550 sq ft	—	Yes	—	U-shaped, window stays openable (22-36 in wide, 13.75 in min height)	Check price →
Our verdict Our verdictResearched The largest of Midea's U-shaped units at 12,000 BTU, rated for 550 sq ft by the maker. Same openable-window design as the smaller sizes, with an inverter and app control. The listing we read doesn't state a CEER. Best for A large room where you want to keep the window usable Good Window can still open Inverter and Wi-Fi control Highest BTU in the U line Worth knowing CEER not stated on the listing Needs a 22-36 in wide window Who shouldn't buy it: Don't buy it if your window is narrower than 22 inches.
4. Midea 6,000 BTU U-Shaped Smart Inverter Window Air Conditioner Best for a small room 6,000 BTU · 250 sq ft · Yes · U-shaped, window stays openable (22-36 in wide, 13.75 in min height) A small bedroom where you want to keep the window usable 4.4	6,000 BTU	250 sq ft	—	Yes	—	U-shaped, window stays openable (22-36 in wide, 13.75 in min height)	$314.99 at Amazon as of Nov 9, 2026, 11:40 AM ET · Details Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. In stockCheck price →
Our verdict Our verdictResearched The U-shaped design leaves the window openable with the unit in place, and the listing describes inverter control, Wi-Fi and voice control. It is the smallest of Midea's U line at 6,000 BTU for rooms up to 250 sq ft by the maker's figure. The listing doesn't state a CEER. Best for A small bedroom where you want to keep the window usable Good Window can still open Inverter and Wi-Fi control Quiet, down to 32 dBA by the maker Worth knowing CEER not stated on the listing Needs a window at least 13.75 in tall Who shouldn't buy it: Don't buy it if your window is narrower than 22 inches or is a casement window.
5. Midea 8,000 BTU Smart Inverter Window Air Conditioner with Heat and Dehumidifier 8,000 BTU · 350 sq ft · Yes · Yes, heat pump (works when outside temp is above 41°F) · Standard double-hung window, 24-38.5 in wide, 14.5 in clear opening Cooling plus some heat in spring and fall 4.4	8,000 BTU	350 sq ft	—	Yes	Yes, heat pump (works when outside temp is above 41°F)	Standard double-hung window, 24-38.5 in wide, 14.5 in clear opening	$399.99 at Amazon as of Nov 9, 2026, 11:40 AM ET · Details Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. In stockCheck price →
Our verdict Our verdictResearched An inverter window unit that also heats, with the maker's note that the heat pump works when outdoor temperature is above 41°F. It is a conventional window install, not the U-shaped design. The listing states ENERGY STAR but no CEER. Best for Cooling plus some heat in spring and fall Good Heat mode as well as cooling Inverter and ENERGY STAR per listing Wi-Fi and voice control Worth knowing Heat only above 41°F outside Blocks the window while installed Who shouldn't buy it: Don't buy it if you want a primary heat source; the maker calls it supplemental heat.
6. LG 8,000 BTU Smart Wi-Fi Enabled Window Air Conditioner LW8023ERSM 8,000 BTU · 350 sq ft · Installs in most windows (maker's wording) A medium bedroom with an LG app and a standard window 4.2	8,000 BTU	350 sq ft	—	—	—	Installs in most windows (maker's wording)	Check price →
Our verdict Our verdictResearched A well-known brand's 8,000 BTU Wi-Fi window unit for spaces up to 350 sq ft, with a remote and an Energy Saver mode. The product page text we could read doesn't list CEER, heating or an inverter, so check the label. Best for A medium bedroom with an LG app and a standard window Good Wi-Fi app control Remote and Energy Saver mode Rated for 350 sq ft by LG Worth knowing CEER and inverter not stated on the page Blocks the window while installed Who shouldn't buy it: Don't buy it if you want a model with a published CEER you can compare first.
7. Midea 5,000 BTU EasyCool Window Air Conditioner 5,000 BTU · 150 sq ft · Standard window frame; mounting accessories included, screwdriver needed A small office or dorm-sized room 4.1	5,000 BTU	150 sq ft	—	—	—	Standard window frame; mounting accessories included, screwdriver needed	$169.99 at Amazon as of Nov 9, 2026, 11:40 AM ET · Details Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. In stockCheck price →
Our verdict Our verdictResearched A basic 5,000 BTU window unit for rooms up to 150 sq ft, with a remote, eco mode and timer. It installs in a standard window frame with a screwdriver. The listing doesn't mention an inverter, CEER or heat. Best for A small office or dorm-sized room Good Compact 5,000 BTU size Remote, timer and eco mode Removable, reusable filter Worth knowing 52 dB on low per listing CEER not stated Who shouldn't buy it: Don't buy it if your room is bigger than about 150 sq ft.

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The honest bit

Buy the size the room needs, not the biggest: an oversized unit cools fast but cycles off before it pulls the damp out, and the room feels clammy. Check your window first; a U-shaped unit needs a window that opens up and down within its stated width range, and casement or sliding windows need a portable or a casement unit instead. Like any AC, these need wall power: they won't run in an outage without a generator. If you only need relief for a few hot nights in an outage, a battery fan is far cheaper.

Before you buy

Size to the room.

The makers' room sizes here run from 150 sq ft for 5,000 BTU to 550 sq ft for 12,000 BTU. Sunny rooms and kitchens need more; shaded rooms less.

Consider a U-shaped inverter for bedrooms.

Midea's U-shaped units sit across the window sill so the window can still open, and their inverter compressors slow down instead of switching on and off.

Want heat too?

Midea's 8,000 BTU heat-pump model also heats, but only when it's above 41°F outside, so it's for mild spring and fall days, not a winter heater.

Check the window size and type.

Each unit lists the window widths it fits. Window units suit double-hung (up-and-down) windows; for sliding or casement windows look at portable air conditioners.

Install it securely.

Use the supplied brackets and follow the manual.

How we choose

We verify every product's specifications against at least two independent sources, re-check its US price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labeled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test. When two products are close, commission can decide which one we pick. A clearly better product always wins. Read our full methodology →

Related gear comparisons

Portable air conditioners compared →Battery-operated fans compared →Battery air conditioners compared →Dehumidifiers compared →

Guides that go with this

Extreme heat safety: heat exhaustion vs heat stroke and how to stay cool in a power outage

Heat exhaustion vs heat stroke signs and what to do, why a fan is not enough when it is very hot, heat alert t…

Read the guide →

Common questions

What size window air conditioner do I need?

Use the maker's room size as a starting point: about 150 sq ft for 5,000 BTU, 250 for 6,000, 350 for 8,000, 450 for 10,000 and 550 for 12,000 among the units here. Add capacity for a sunny room or a kitchen.

Is a window AC better than a portable AC?

Usually, if it fits. A window unit keeps its hot side outside, while a portable's hot parts sit in the room and vent through a hose, which is why portables carry a lower DOE rating than their box figure suggests.

What is a U-shaped window air conditioner?

A unit shaped like a U that straddles the window sill, so the sash closes down into the gap. Midea's say the window stays openable, and the design puts the noisy compressor outside.

Can a window air conditioner heat?

Some can. Midea's 8,000 BTU heat-pump model on this page heats when it's above 41°F outside. It's not a substitute for a furnace in winter.

Are fans enough in a heat wave?

Not when it's very hot. CDC says don't rely solely on fans to keep you cool, and suggests air-conditioned places, even for a few hours.

Sources (2)