Top 5 Side Open Window AC Units: Expert Review

Is your regular window air conditioner just not cutting it? Maybe your window opens in a way that makes standard AC units impossible to install. You know that feeling: the summer heat is creeping in, and you need cool air fast, but your window is shaped all wrong for the usual boxy units. It’s frustrating when a simple solution seems out of reach!

Choosing a side open window air conditioner presents unique challenges. You worry about a secure fit, proper sealing against the outside air, and getting enough cooling power for your room size. Many people feel lost when looking at these specialized units. They want comfort without the hassle of complicated installations or poor performance.

This guide cuts through the confusion. We will break down everything you need to know about side open window ACs. You will learn how to pick the perfect model, ensure a safe setup, and enjoy perfectly cool rooms all summer long. Get ready to stop sweating the small stuff!

Top Side Open Window Air Conditioner Recommendations

Bestseller No. 1

Midea 8,000 BTU U Shaped Smart Inverter Window Air Conditioner - Cools 350 Sq Ft, Ultra Quiet with Open Window Flexibility - Alexa/Google Assistant Compatible - 37% Energy Savings, Remote (Updated)

ULTRA QUIET - The U-shape design of Midea U Smart Inverter air conditioner uses your window to block noise outside. The highly-efficient inverter system warrants ultra-low noise and vibration, 10x quieter than traditional units with operation as low as 32 dBA. Cooling Watts: 710W, Rated Cooling Amps (AHAM): 8.78.Airflow (CFM) Roomside (hi low): 215/150. Refrigerant: R32.
MORE THAN 37% ENERGY SAVINGS - With the advanced DC Inverter technology, Midea U window air conditioner achieves over 35% energy savings compared to other traditional units. It is the first window AC to obtain the ENERGY STAR Certification.
SMART CONTROL - Midea U Smart Inverter air conditioner is Wi-Fi enabled and can be controlled from anywhere using the SmartHome app on iOS or Android. You can also use voice commands throughout your house, office, or apartment using Alexa or Google Assistant devices.
FLEXIBLE WINDOW OPENING - The U-shaped design allows your window to open, bringing fresh air into your home and maintaining more of your view when the window air conditioner is installed. When the window is closed, the Anti-Theft Mechanism locks the window for added safety.
ROBUST INSTALLATION - Install the included quick-snap bracket, set the air conditioner on the bracket, and secure the sidearms. Then you are all done and ready to enjoy. Available for single-hung or double-hung windows with width 22"-36", minimal height at 13.75".

Bestseller No. 2

Amazon Basics 6000-BTU Window Air Conditioner, Up to 250 Sqf, Window AC Units with Cool and Fan Functions, Washable Filter, Adjustable Window Kit, Digital Temperature Display, Remote Control, White

EFFICIENT COOLING: 6000 BTU cooling capacity ideal for rooms up to 250 sq. ft. - perfect for bedrooms, home offices, or small to medium living spaces. Two-in-one functionality with cooling and fan-only modes
SMART MAINTENANCE: Equipped with an easy-access, washable filter that captures dust and allergens.
CUSTOMIZABLE COMFORT: Features 7 precise temperature settings, 2-speed cooling and fan modes, and 2-way air direction control for personalized comfort
QUIET OPERATION: Low noise level up to 56 dB creates a peaceful environment suitable for sleeping and working
QUICK INSTALLATION: Fits standard windows 23"-36" wide and minimum 13" high. Comes with expandable side panels and complete mounting kit. Basic tools required for installation (screwdriver not included)

Bestseller No. 3

Gruntbear Portable Air Conditioner Window Seal Kit, 400CM (157'') AC Casement , Hot Air Stop Air Exchange Guards with Zip and Adhesive Fastener Works with Tumble Dryer, Keep House Cool

Move Hot Air Out of Room: This portable ac window seal install between the window frame and the window with a hose, effectively expelling the hot air produced by the air conditioner out of the window, keeping the cold air inside and keeping your room cool for a long time
Enhance Cooling Performance & Save Energy: Gruntbear air conditioner window seal are made of durable nylon material, which can effectively block the entry of hot air, let your room cool down quickly in a short time, enhance the cooling performance of AC, help reduce energy consumption, reduce CO2 emissions, save your power consumption and save your money
Waterproof Function: Gruntbear casement window air conditioner seal are made of waterproof nylon material and can also be used in rainy days. Create a cool space for you on sweltering summer days
Easy to Install: No drilling and tools required, everything you need is provided by Gruntbear. Simply tape the portable ac window vent kit to the inside of the window frame and to the window, place the AC hose out of the window, zip it up, and secure with a zip tie. You can open or close the window at any time without removing the window seal
Wide Application: The 400cm air conditioner crank out window kit is suitable for both push-out and pull-in window types and will fit windows up to 157 inches in circumference. Suitable for skylights, awning window, casement window, or crank out window that opening to the left or to the right, not suitable for sliding windows, vertical push-pull window, or stereo revolving windows

Bestseller No. 4

Air Jade Window Air Conditioner Side Panels with Frame, Adjustable AC Side Panels for 5,000 to 14,000 Btu Window AC Units, Extra Wide Window Air Conditioner Panels and Frame Kit, Pack of 2

✅ Upgrade Height-adjustable - Our window AC side panels with frame can be adjusted to fit window opening height up to 17", universally fit most window AC units from 5,000 to 14,000 Btu.
✅ Extra Wide Side Panels - The window AC side panels can be extended up to 15" wide each side, it's wider than other air conditioner side panels on the market, ideal for wider window openings.
✅ High Quality Material - Made of flexible and special soft vinyl material that provides excellent insulation, wind and dust resistance, the adjustable window air conditioner side panels can be easily cut to fit your desired height.
✅ Side Panel Replacement Kit - Foam sealing strip provided to seal the possible gap, and detailed installation instructions for your convenience. Our AC Side Panel Replacement Kit is perfect for replacing your old cracked/damaged side panels, with no air leaking through the holes.
✅ In the Package - The adjustable window ac side panels include 2 panels with frame, left & right side, 1 roll foam seal strip and installation instructions. Please check your original frame or window unit's height.

SaleBestseller No. 5

GE Profile ClearView Window Air Conditioner Unit, 8,300 BTU, U-Shaped Adjustable Depth, Energy Efficient Cooling up to 350 sq ft., Ultra Quiet, SMART Home Capable, Includes Remote, White

FULL WINDOW VIEW: This innovative window air conditioner is designed to maintain the full view through the window, letting it open and close freely after you install the unit and allowing more natural light into the room. Fits windows 20"-40" wide, 13" minimum window opening height, 10" minimum height from floor
ULTRA QUIET OPERATION: This quiet air conditioner reaches sounds as low as 40 dB, underlining GE Profile's rating as the Quietest Window AC Brand in the US; ClearView's operation keeps the air flowing for minimal disruption
INDUSTRY EXCLUSIVE FLEX-DEPTH: The flex-depth design is engineered to expand to multiple positions, accommodating walls between 4.5" and 13.75" thick. The unit comes in the closed position and can be adjusted based on your windowsill depth for a secure, custom fit
BUILT IN WI-FI - Use the SmartHQ app to control and monitor this WiFi-enabled smart air conditioner from anywhere, giving you connected peace of mind, while compatibility with your favorite devices like Amazon Alexa and Google Assistant makes everyday use easier and more versatile than ever; or you can use the included remote control
BUILT IN PUMP: An advanced built-in pump system collects the condensation from the indoor side then automatically transports the water through the unit to empty efficiently outside

Bestseller No. 6

Midea 12,000 BTU Smart Inverter Air Conditioner Window Unit with Heat and Dehumidifier – Cools up to 550 Sq. Ft., Energy Star Rated, Quiet Operation, Electronic Controls, Remote Control, White

Multi-Season Comfort - This Midea 12000 BTU air conditioner is better than standard ac units. It will beat the heat in summer with powerful cooling and dehumidification and keep you warm through the fall with supplemental heat. Best for large rooms up to 550 square feet. NOTE: heat pump function will not work if outside temp is 41°F or below..Control Type : Electronic.
Easy To Use – This air conditioner and heat unit comes with an LED display, 5 Modes (Heat, Auto, Cool, Dry, Fan), 3 speed settings (Auto/H/M/L), 24-hr Timer, and ECO energy saver. The Swing button adjusts the louvers up/down to direct the airflow. Wireless control enabled window ac with heat unit from anywhere with the SmartHome App, or with your voice via Alexa and Google Assistant. All functions can be set via the control panel, remote control, and app or voice assistant.
Save Energy Being Cool – Save on energy costs and enjoy ultimate comfort with this energy star certified unit. This energy efficient air conditioner unit is engineered with variable-speed inverter technology that will quickly cool your bedroom or apartment space while using considerably less electricity; up to 35% energy savings compared to the Energy Conservation Standard. Cooling 12,000 BTUs, CEER 13.3, 115V, UL listed, Automatic Shutoff and Defrost Control. Washable filter is easily accessed from front panel for regular cleaning to maintain peak performance.
Ultra Low Noise Performance – This ac window unit operates at a noise level as low as 45 dBA. It’s such a quiet air conditioner that you will barely notice it, even when it’s on high. Enjoy your Zoom call, watch your favorite TV show, have a conversation. This ac unit for bedroom also creates just the right amount of white noise so you can get some rest.
Install Specs – This window air conditioner is designed to fit double hung windows with opening widths of 24 to 38.5 inches. Lower sash must open sufficiently to allow a clear vertical opening of 14.5 inches. AC window unit measures 19.41"W x 22.17"D x 13.9"H. Included components: 12000 btu window air conditioner, remote control, installation kit. This ac heater combo window unit is as a close as you can get to a mini split a/c. You may like it so much you just might buy two!

Bestseller No. 7

TCL 10,000 BTU Q-Series Smart Inverter Window AC, Ultra-Quiet 32dB Fan & 40dB Cooling, 38% Energy Saving, 3-Step Install, Open-able Window, Works with Smart Home Devices, Cools up to 450 Sq. Ft.

Powerful Performance: Enjoy this inverter ac’s powerful cooling performance that transforms your space, even on the hottest of days (perfect for up to 450 sq. ft.)
Set Up in as Little as 3 Easy Steps: Install effortlessly: fit this AC into your window, secure its side panels, and cool your home in minutes. Additional steps may be required depending on your scenario. Window Size Requirement: (24-36 inch width, 14.5 inch opening height)
Cools Faster and More Consistently: TCL’s Smart Inverter algorithm ensures quicker, more consistent cooling without harsh noise or heat spikes.
Open Your Window Freely: Embrace ultimate flexibility and freely open and close the window with the improved stability and design.
App, Voice, TV & Remote Control: Control your Q-Series window AC through the TCL Home App on Android and iOS devices, seamlessly integrate with Alexa/Google Assistant/Apple Homekit-enabled devices, effortlessly manage it from your TCL Google TV, or conveniently use the included remote; control the way you want; now Matter certified

SaleBestseller No. 8

Frigidaire 5,000 BTU Window-Mounted Air Conditioner, Cools Up to 150 Sq. Ft., Quiet Operation, Effortless Temperature Control, 2 Fan Speeds, Auto Restart, White

Effortless Cooling: Achieve optimal comfort with customizable temperature settings and two fan speeds; Effortless Temperature Control helps to maintain your preset temperatures for consistent comfort
Easy Maintenance: Keep your air conditioner running efficiently with the easy-to-clean washable filter, designed to capture dust from the air for long-lasting performance
Undisturbed Comfort: Experience a peaceful home environment with a quiet performance at 52 dBA – ideal for bedrooms or small spaces up to 150 sq. ft.
Effortless Convenience: Benefit from the Auto Restart feature, which automatically restores the unit's previous settings once power is restored to the window air conditioner
Hassle-Free Operation: The extra-long three-prong power cord eliminates the need for extension cords, while the adjustable side panels easily extend to best fit your window, ensuring a secure installation with optimal efficiency and airflow

Your Complete Buying Guide for Side Open Window Air Conditioners

Side open window air conditioners are great for rooms where a regular up-and-down window unit just won’t fit. They slide sideways into your window opening. This guide helps you pick the best one for your cooling needs.

1. Key Features to Look For

When shopping, check these important features first. They make a big difference in how well the AC works and how easy it is to use.

BTU Rating (Cooling Power): This number tells you how much space the AC can cool. A small room needs fewer BTUs than a large living room. Always match the BTU rating to your room size.
Energy Efficiency Rating (EER/SEER): Look for high EER or SEER numbers. Higher numbers mean the AC uses less electricity to keep you cool. This saves you money on power bills.
Noise Level (Decibels – dB): ACs make noise. If you plan to use it in a bedroom or office, look for lower decibel ratings (under 55 dB is usually quiet).
Programmable Timer and Remote Control: These features let you set cooling schedules and change settings without getting up. They add great convenience.
Airflow Direction Control: Good units let you adjust where the cool air blows. This helps cool the whole room evenly.

2. Important Materials and Build Quality

The materials used affect how long your AC lasts and how well it handles the weather outside.

Casing Material: Most outdoor casings are made of durable plastic or coated metal. Look for rust-resistant coatings, especially if you live near the coast or where it rains a lot. Strong plastic resists dents better than thin metal.
Internal Components: Copper coils are generally better than aluminum coils. Copper transfers heat better and lasts longer.
Filter Quality: Check the air filter. Reusable, washable filters save you money over time. Good filters trap more dust and keep the unit running efficiently.

Factors That Improve or Reduce Quality

Quality isn’t just about the price tag. Certain things boost performance, while others cause problems later.

What Improves Quality:

Inverter Technology: Inverter ACs adjust their speed instead of constantly turning fully on and off. This saves energy and keeps the temperature steadier.
Sturdy Mounting Hardware: Since these units hang partly outside, strong mounting brackets and seals are vital for safety and preventing leaks.

What Reduces Quality:

Poor Insulation: Cheap units might have weak insulation around the cabinet. This lets the cold air leak out or warm air seep in, making the AC work harder.
Weak Seals: If the side panels don’t seal tightly against the window frame, bugs, drafts, and moisture can enter your room.

3. User Experience and Use Cases

How you plan to use your AC heavily influences your choice.

For Bedrooms:

You need a quiet unit (low dB) with a good sleep mode. Side open units are often quieter than traditional window models because the noisy compressor sits further to the side.

For Small Offices or Dens:

Focus on energy efficiency (high EER) and reliable cooling power (BTU). You want the AC to handle long hours of use without spiking your electric bill.

Installation Considerations:

Side open models are often easier to install than traditional models because you often slide them in and secure the sides, rather than lifting a heavy, tall unit. However, always check that the included installation kit fits your specific window type.

10 Frequently Asked Questions (FAQ) About Side Open Window ACs

Q: Are side open window ACs hard to install?

A: Generally, they are easier than standard window units. You slide them into the opening, and then you secure the side accordion panels to the window frame.

Q: Do side open ACs cool as well as regular window ACs?

A: Yes, if the BTU rating matches the room size, they cool just as effectively. The cooling mechanism is the same.

Q: Are these units very noisy?

A: Noise varies by model. Look specifically for units listing lower decibel (dB) ratings if quiet operation is important to you.

Q: Can I use a side open AC if my window doesn’t open vertically?

A: Yes! That is their main advantage. They fit well in sliding sash windows or sometimes even casement windows if you use the right adapter kit.

Q: How do I clean the air filter?

A: Most models come with a removable, reusable filter. You usually slide it out, rinse it with warm water, let it dry completely, and then slide it back in.

Q: Do these units use more energy?

A: Not necessarily. Energy use depends on the EER rating and whether it has inverter technology, not the side-opening design itself.

Q: What is the typical lifespan of a side open AC?

A: With regular maintenance, a quality unit should last between 8 and 12 years.

Q: Will bugs get in through the side panels?

A: Good models include durable, tight-sealing accordion panels. Always check user reviews to ensure the seals are effective against pests.

Q: Do I need professional installation?

A: Many people install them themselves following the manual. However, if you are unsure about securing the exterior brackets safely, hiring a professional is wise.

Q: What is the advantage of a side open unit over a portable AC?

A: Side open window units are much more efficient. They vent hot air directly outside through the window opening, whereas portable ACs often lose cooling efficiency through internal ducting.