6 Best Air Conditioners For Horizontal Sliding Windows 2020

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You can’t install a traditional window air conditioner in casement or sliding windows. What you need is an air conditioner for horizontal sliding window.

Most horizontal window units are a little expensive than units that fit in double-hung windows. The good thing about them is that they have added features, including programmable thermostats, multiple fan speeds, and WiFi capabilities. You also don’t have to modify your windows during installation.

If you’re on the market for the best sliding window ac unit, here is a review of the top six options on the market today.

Best Air Conditioner For Horizontal Sliding Window 2020

1. Frigidaire FFRS1022R1 Slider/Casement Room Air Conditioner 

LG LT1037HNR 10000 230V Through-The-Wall with...
  • Your purchase includes One LG 10,000 BTU Air Conditioner with 11,200BTU suplemental Heater, in White | Through-the-Wall Remote Control & Installation Kit included
  • Air conditioner dimensions – 24” W x 14.41” H x 20.09” D | Weight – 78 lbs. | Indoor Noise Max rating – 56 dB | Voltage – 230V 60Hz
  • Cooling Performance – 9,800/10,000 BTU | Heating Performance – 9,200/11,200 | Dehumidification: 3.2 pts/hr. | Estimated cooling area – 450 Sq. Ft. | Estimated heating area – 450/550 Sq. Ft. | Refrigerant – R410A | CEER – 9.7/9.7
  • The cool and the heat mode is available for year-round use, keeping you cool during hot summers and warm during cold winters
  • Operate with LED display and simple selection control panel, up/down temperature adjustments, and fan speed selection, using the full-featured remote without leaving your bed, workspace, or couch

The Frigidaire FFRS1022R1 is a powerful window ac that is specially designed to fit casement windows between 15.5-16.25 inches wide and 20.5-40 inches high. It produces 10,000 BTUs of cooling power enough to cover rooms up to 450 square feet and can remove up to 3.4 pints of moisture per hour when used as a dehumidifier.

This unit has an energy efficiency ratio of 10.4, and it comes with a programmable thermostat that lets you select temperatures between 60 and 90 degrees Fahrenheit. It also features an energy-saving operation mode that shuts down the compressor when the temperature levels match what you set. The unit will only turn the compressor back on when temperatures rise above your set point. 

This Frigidaire casement window unit also has a fan with three speeds and four-way air directional louvers that allow you to direct cold air to where you need it. 


  • It has a programmable timer
  • Sleep mode
  • Washable air mesh filter
  • Programmable thermostat
  • It is remote controlled
  • Operates quietly 


  • It doesn’t include a heat function
  • It is exclusively for casement windows

2. Frigidaire FFRS0822S1 Casement Window Air Conditioner

Frigidaire FFRS0822S1 8000 BTU Heavy-Duty Slider...
  • Beat the heat while remaining cool and happy on hot summer days
  • With 2344.57 W cooling power, enjoy a blast of cool air throughout your room
  • Effectively cools area of up to 350 Sq. ft., this air conditioner is perfect for bedrooms
  • Provides enough cooling in your room with 3 fan speeds
  • Full-function remote control allows you to precisely control the temperature and fan speed from across the room
  • Power source type: Corded Electric
  • Mounting type: Casement/Slider

The Frigidaire FFRS0822S1 is a powerful heavy-duty air conditioner ideal for spaces up to 350 square feet. It is specially designed for casement or sliding windows that are 15.5 inches wide and up to 40 inches high.

This 8,000 BTU window ac features a 24-hour timer that lets you set the unit to turn on or off as you please. This feature keeps your home cool and comfortable all the time without the risk of running up your electricity bills. It also has an automatic restart feature that lets the unit resume cooling with all previous settings in case of power problems.

This Frigidaire ac unit has washable antibacterial air filters that are easy to access for maintenance and a filter alert that notifies you whenever the filter needs cleaning. In addition to that, it features a fan with three speeds and 4-way air directional louvers that allow you to direct cool air to where you want it.


  • It doubles as a dehumidifier
  • It has an antibacterial air filter
  • 10.8 EER rating
  • It comes with a full-function remote control
  • Variable fan speeds and airflow directions


  • This ac is loud when the fan is on high speed.

3. Koldfront 115V Casement Air Conditioner with Dehumidifier

Koldfront CAC8000W 8000 BTU 115V Casement Air...
  • 8000 BTU vertical window air conditioner engineered for spaces ranging in size from 300 to 350 square feet
  • Designed to fit casement (left to right sliding) windows ONLY, and will not fit windows that slide up and down. Fits windows 15-1/2" to 16-1/4" wide with a minimum height of 21-1/4" when using the window panel retainer and a maximum height of 39-7/16" (minimum window height of 20-5/16" without the window panel retainer)
  • Digital Display; Dehumidifier; Sleep Mode; 3 fan speeds; Remote control with 16ft range; LCDI 5-15P plug type
  • Energy Efficiency Ratio (EER): 11.0 / Energy saver mode
  • Includes all installation hardware and weather seals

The Koldfront CAC8000W is a powerful casement window ac that is sure to keep the heat at bay with a long-lasting cool breeze. It produces 8,000 BTUs of cold air enough to chill spaces between 300-350 square feet, which makes it ideal for use in bedrooms and large living rooms and offices.

It is energy-star certified because it has several features that ensure your space stays cool all the time without running up your electricity bills. These features include sleep mode, energy-saving mode, thermostat-controlled operation, among others. It also has a control panel with a digital display and a remote lets you operate the unit from up to 16 feet away.

The Koldfront CAC8000W Window ac is designed to fit in window frame from 15.5 – 16.25 inches wide and a minimum height of 21¼ inches with the window panel retainer. Minimum height reduces to 20 inches without the retainer. It is easy to install, and it comes with all installation accessories and weather seals.


  • It dehumidifies
  • It has a 3-speed fan
  • Digital display with multiple settings
  • Energy efficient
  • It comes with a full installation kit.


  • It does not have a timer.

4. PerfectAire 3PASC10000 Slider Window Air Conditioner

PerfectAire 10,000 BTU Slider Air Conditioner...
  • Adjustable temperature settings that range 62°F - 86°F (17°C - 30°C); cools areas between 400-450 sq. ft.
  • Expandable window mounting kit accommodates horizontal sliding or crank-out casement windows with a 15½”/16¼” (min./max.) window width and a 21¼”/39½” (min./max.) window height
  • 3-speeds in both cool and fan modes
  • Full function remote control with Follow Me portable thermostat technology for total room coverage
  • Front-mounted, tilt-out air filter access for easing cleaning

The PerfectAire 3PASC10000 is a 10,000 BTU window ac that can cool rooms up to 450 square feet. It is designed for casement windows with widths between 15.5 inches-16.24 inches and heights between 21¼ – 39½ inches.

This unit features four operating modes that allow you to customize your indoor climate fully. These include a cooling mode, a fan mode, dehumidification, and auto, where the unit chooses the best operating mode according to the natural climate changes in your space. It also has adjustable temperature settings that range between 62°F – 86°F.

The PerfectAire 3PASC10000 also has a removable and washable air filter that keeps your air clean and healthy. It also has an exhaust control to circulate air inside the room or push it outside.


  • It has four operating modes
  • It has washable filters
  • Three fan speeds and adjustable air louvers
  • Follow me remote feature
  • It has a check filter indicator.
  • Adjustable timer


  • This is a cool-only AC. It does not have a heat mode.

5. Global Industrial Casement Window Air Conditioner 

Global Industrial Casement Window Air Conditioner...
  • Installation Kit Included
  • Auto restart, Sleep mode, 24hr on/off timer, Follow Me, R410 A eco-friendly refrigerant
  • Easily-Removable and Washable Filter Included
  • BTU Cooling: 10,000

The Global Industrial MWDUL-10CRN1-BCJ4 is a powerful compact and energy-efficient window ac that can serve spaces up to 450 square feet. It has a powerful fan with three speeds and four-way air direction louvers which allow you to choose where to direct cold air.

This 10,000 BTU ac also features an auto-restart mode that restarts your unit with all previous settings intact in case power shuts down. Furthermore, you can set the unit to sleep mode at night to maintain your preferred temperatures all night without consuming a lot of energy or disturbing your sleep.

In addition to that, it has an LED display that allows you to see the adjustments you make and a remote that lets you operate the unit from anywhere in the room.


  • It has adjustable speed levels
  • Cools a large area
  • It is remote controlled
  • It has an easily accessible washable air filter
  • It uses an eco-friendly refrigerant
  • A full installation kit included.


  • It is noisy at high fan speed.

6. Danby DAC100B1WDB 10,000 BTU Window Casement Air Conditioner

Danby DAC100EB1WDB 10,000 BTU Window Air...
  • Excellent Cooling Power: This 10,000 BTU window air conditioner with Follow Me Function quickly cools your room
  • Window air conditioner ideal for spaces up to 450 square feet
  • Powerful Air Circulation: Powerful 3 speed fan and 4-way air direction circulates the air in the room
  • Follow Me Function: Remote control acts as a thermostat allowing for more precise temperature control
  • Programmable Timer: This window unit air conditioner has a convenient 24-hour programmable timer
  • Comfort Sleep Mode: The Sleep mode prevents the room from getting too cold while you sleep
  • Modern Look: Electronic controls with LED display give a smooth modern look
  • Reusable Air Filter: The air filter is reusable and washable
  • Auto Restart: The air conditioner automatically restarts after a power failure

The Danby DAC100B1WDB window air conditioner contains 10,000 BTUs of cooling power perfect for chilling spaces up to 450 square feet. It is designed to fit casement windows that are 15.4 inches wide and have heights between 20.9 – 39.6 inches.

This unit has a powerful 3-speed fan and four airflow directions that allow you to direct the cold air to where you want it. It also features electronic touch controls with LED display and a full-function remote to give you total control of your indoor climate. 

This Danby Casement window unit is energy star rated, and it is equipped with several features that keep your electricity bills low. You can set the 24-hour timer to turn the unit on and off as you please, and you can enable “sleep mode” at night to let the air conditioner adjust the temperatures all night to keep you comfortable as you sleep.

The Danby DAC100B1WDB is easy to install, and a full installation kit comes with the package. In addition to that, Danby offers you a 12-month warranty on parts and labor.


  • It has a full feature remote control
  • 24 hr. programmable timer
  • Sleep mode keeps you comfortable while saving energy
  • It has removable and washable filters
  • Easy to install(full installation kit included)
  • 12-month warranty on parts and labor


  • This unit lacks intrusion protection and an insect barrier.

Wrap Up

Cooling your space using an air conditioner for horizontal sliding window doesn’t have to be complicated. The products I’ve reviewed above delivers unrivaled cooling to both residential and commercial spaces.

Remember, this is a guideline, and you should determine the size of your room to help you pick the right BTUs for your sliding window air conditioner.

You should also consider the size of your window since casement/horizontal windows are more narrow than double-hung windows.