Smallest Window Air Conditioners for Small Windows


Smallest Window Air Conditioners

A window of fewer than 25 inches wide or opens at lower than 15 inches can’t fit a standard air conditioner. Keep a cool head though! There is the so-called smallest window air conditioner that is just as powerful as its bigger counterpart.

Also called the mini room air conditioner, this type of air conditioner has around 5,000 to 6,000 British Thermal Unit (BTU) that perfectly cooling and humidify dry air your room spaces of up to 450 square feet. For a standard bedroom of 305 sqft. it is more than enough.

When it comes to choosing a mini-compact air conditioner, there are few things you need to know. First, the factors to consider such as the cooling capacity, fan speeds, energy efficiency, and comfort features. To lessen the hassle of looking for the best smallest window AC, we did some research and came up with a detailed review of each of the best-selling units today.

Our Best 7 Window Air Conditioner Reviews

This table shows the general description and differences between our chosen window air conditioners.

Below this table is a thorough review of each product to help you further in identifying the best unit for your specific needs and preferences:

Product NameBTUCoveragePrice
Koldfront WAC12002WCO12,000550 sqftCheck Price
SPT WA-1222S12,000550 sqftCheck Price
LG LW8016ER Energy Star8,000340 sqftCheck Price
Keystone 5000 BTU5,000150 sqftCheck Price
Frigidaire FFRA0511R15,000150 sqftCheck Price
Costway 5000 BTU5,000120 sqftNo products found.
HomeLabs 5000 BTU5,000120 sqftCheck Price

1. Koldfront WAC12002WCO

Koldfront Window Air ConditionerThe smallest window AC that tops our list has the highest cooling capacity with a low voltage. With 12,000 BTU, the Koldfront WAC12002WCO can cool a room size of up to 550 square feet. It provides temperature between 62 to 86 degrees F and comes with a 24-hour timer.

As one of the Energy Star-rated small window AC, it is guaranteed energy-efficient. Its input voltage is 115 which is equivalent to 60 Hertz. Plus, it has energy-saving functions such as the three fan speeds, sleep mode, dry mode, and other automatic function.

For convenience, this Koldfront WAC12002WCO comes with remote control. Its four-way directional louvers improve the consistent air flow throughout the entire room. It can fit in a window with a minimum height of 15.5 inches and width 23 to 36 inches.

  • Energy efficient with auto functions and a 24-hour timer
  • Cools room as large as 550 square feet
  • Highest cooling capacity among the other small window air conditioner
  • Functions at low voltage (115v or 60Hz)
  • Directional louvers and fans maintain consistent air flow
  • Energy Star-rated
  • Doesn’t come with optional installation service
  • Basic yet powerful functions and features

2. SPT WA-1222S

SPT WA-1222S Window Air Conditioner - Energy StarThe SPT WA-1222S has the same cooling capacity and voltage requirement as the Koldfront WAC12002WCO. For the 12,000 BTU at 115 volts, it increases the room temperature of up to 62 to 86 degrees F. It perfectly cools down a single room or studio room between 450 to 500 square feet. One unique feature is the odor removal vent that helps convert air quality of your room into fresh and clean air.

The energy-saving modes of SPT WA-1222S are dry, energy saver, sleep, and auto. It comes with a built-in thermostat that controls the energy-saving mode and the three fan speeds. The 24-hour timer with auto restart feature also contributes to the energy-efficiency along with the remote control and digital display.

As a window-mounted air conditioner, the SPT WA-1222S is easy to install to your room. It can easily fit in a window that ranges from 23 to 36 inches with a minimum height of 15.5 inches. It comes with a window mounting kit for easy DIY installation. Another best thing about this window air conditioner is the detachable air filter for convenient washing and maintenance.

  • 24-hour timer with auto functions
  • The large cooling capacity of room up to 550 square feet
  • Versatile window installation from 23 to 36-inch width and 15.5-inch height
  • This air conditioner comes with an installation kit
  • Detachable, washable filter
  • Energy Star-rated
  • Air vent construction that removes odor and improves air quality
  • User-friendly remote control with digital display
  • Quite expensive compared to other products in the list
  • Molds may form in the Styrofoam insulation of the unit

3. LG LW8016ER Energy Star

LG LW8016ER Window-Mounted AIR Conditioner with Remote ControlFor smaller rooms of up to 340 square feet, this LG LW8016ER Energy Star is sufficient. It has a cooling capacity of 8,000 BTU and requires a 115-volt electrical outlet. As an Energy Star-rated BTU Air Conditioners unit, it features a 12.1-energy efficiency ratio that quickly cools the room without raising your electric consumption too high. Its cooling mechanism also comes with a dehumidification function of up to 2.2 pints per hour.

The easy-to-use remote control allows you to manage this window air conditioner, even from the other side of the room. It comes with a 24-hour automatic power on/off function and three cooling/fan speeds. The housing is protected with a patented gold fin anti-rust coating. Additionally, it is easy to install because it comes with an installation kit or an expert installation for an additional fee.

The LG LW8016ER Energy Star comes in other models each with a respective price and cooling capacity. Some models have a Wi-Fi function with cooling speeds from 6,000 to 18,000 BTUs.

  • 12.1-energy efficiency ratio
  • Comes with an installation kit or optional installation service
  • Made with anti-corrosion coating for long-lasting quality
  • Convenient remote control with 24-hour auto power functions and cooling speeds
  • ‘With Wi-Fi’ and models, various cooling capacities are also available
  • Smaller cooling capacity which may not be appropriate for large rooms
  • Noisy operation
  • Window fins screw into the window sill instead of the small air conditioner
  • No directional louvers

4. Keystone 5000 BTU

Keystone Window-Mounted Air ConditionerIf you have a limited budget and need a window air conditioner for a small room, this Keystone 5000 BTU is a perfect choice. It can cool a room up to 150 square feet and dehumidify it up to 1.3 pints per hour. Plus, it has a two-way airflow direction that easily adjusts to the desired direction of the cold air.

The Keystone air conditioner has three cooling speeds and three fan speeds each with the individual indoor room noise level. The temperature sensing remote control allows you to adjust the temperature and control other functions. The 24-hour on/off programmable timer functions according to your preference and desired settings.

The energy-saving modes of the Keystone 5000 BTU cut operating costs and conserve energy. The sleep mode slowly increases the unit’s temperature, and the auto re-start feature restores air conditioner settings after a power interruption. Last but not least, the tilt-out mesh filter comes with a filter alert, so it’s easy to clean and maintain the air quality being circulated throughout the room.

  • Minimal noise level
  • 24-hour programmable functions
  • Two-way airflow direction
  • Easy-to-clean, tilt-out mesh filter with filter alert
  • Energy-saving features and capacity
  • Convenient temperature sensing remote control
  • Restores unit’s previous settings after a power interruption
  • Comes with dehumidification function for your room
  • Low BTU that cools a small room
  • Might stop functioning correctly after several months
  • Drainage issue that causes bacteria build-up in the vent

5. Frigidaire FFRA0511R1

Frigidaire FFRA0511R1 Window Mounted Mini Compact Air Conditioner 5000 BTUAnother 5000-BTU window-mounted air conditioner of the same price as is the Frigidaire FFRA0511R1. It has some critical air conditioner features too. One of them is the easy-to-clean removable filter that allows you to eradicate harmful bacteria, so you enjoy the clean, fresh cold air. Its low noise operation also keeps you comfortable.

The Frigidaire FFRA0511R1 is one of the most compact window air conditioners. It has a 12-inch height, 16-inch width, and 15 ½-inch depths. You can independently set it up your room using the window mounting kit with side panels that comes with the package. Optionally, it comes with expert installation service for an additional fee. Once installed, it can cool spaces up to 150 square feet and dehumidify up to 1.1 pints per hour.

The two-way air direction and two cooling speeds allow you to set the AC according to your preference. The energy efficiency ratio is 11.1 that is low enough to save power consumption. It also starts on low power and has a quiet operation to ensure comfort.

  • Very minimal energy consumption with 11.1 EER
  • Removable filter for convenient cleaning
  • Easy installation with a mounting kit or optional expert installation
  • Has the most compact construction
  • With dehumidification function of up to 1.1 pints per hour
  • Can’t cool huge rooms
  • Doesn’t come with remote control

6. Costway 5000 BTU

COSTWAY 5, 000 BTU 115V Air Conditioner Window-Mounted Mini-CompactThe 5000 BTU cooling capacity of Costway 5000 BTU can cool small spaces room of up to 120 square feet from 61 to 90 degrees F. It also comes with dehumidification function of up to 1.16 pints per hour. It quickly cools a small room with low-energy consumption, so you have huge savings from electric bills.

The energy-saving mechanism comes with a ten-level thermostat, two cooling modes and three fan speeds which can be conveniently adjusted through the mechanical rotary controls. The vents allow you to set the cold air directly to the top, two-way, and full-width. These vents are removable allowing you to wash out bacteria and dust. Moreover, the unit operates quietly to ensure comfort.

This mini-compact window air conditioner is easy to install in your room and saves space. Although its dimensions are a little bit bigger than the Frigidaire FFRA0511R1, it is still considered one of the smallest and lightest units in the industry. It installs on minimum window height of 13 inches and width of 22.3 to 37.5 inches.

  • Fan and cooling speed are adjusted through the mechanical rotary controls
  • Saves energy for 120-square foot spaces
  • 1.16 pints per hour dehumidification
  • One of the most compact and lightest window AC unit in the list
  • Low noise operation
  • Removable filter to prevent bacteria build-up
  • Doesn’t come with a remote control
  • Doesn’t come with an optional installation service
  • Not intended for large rooms
  • Louvers have limited adjustability

7. HomeLabs 5000 BTU

hOmeLabs 5000 BTU Window Mounted Air Conditioner Window AC Unit

One of cost-effective and affordable 5000 BTU window air conditioners is the HomeLabs 5000 BTU. Although it comes last in our list, it has efficient mechanisms that cool down the room air using minimal energy. Its 5000-BTU cooling capacity is sufficient for 150-square foot rooms. It comes with seven temperature settings, two fan speeds, and two-way air vent. In 15 minutes or less, it can eliminate warm air.

The detachable, environment-friendly filter has antibacterial features. You can wash it with warm water and dish soap to remove any harmful bacteria and allergen and maintain the maximum cooling power.

The HomeLabs Air Conditioner 5000 BTU requires a minimal electrical outlet of 110 to 120 volts. As a small window air conditioner, it measures 16 (length) by 12 (height) by 15.4 (depth) inches. It perfectly mounts in windows that measure between 23 to 36 inches wide and 13 inches high.

  • The most affordable unit in the list
  • Cost-effective for small rooms
  • Can cool rooms in as fast as 15 minutes
  • Easy-to-clean removable filter
  • Very adjustable temperature with seven settings
  • Comes with a complete installation package
  • Doesn’t come with remote control
  • Can’t cool large rooms
  • Limited adjustability of air vents

How to Install Window Air Conditioner

Some window air conditioners come with an optional expert installation service, while some come with a complete mounting kit for do-it-yourself installation. Either way, it must be easy for you. A standard window air conditioner is small and lightweight; that’s why a lot of homeowners install it by themselves.

Before you install window air conditioner in your room, make sure that you’ve got the tools you need. Also, the power outlet should be within five feet from the window, or you need an extension cord. After this, you can now start with the installation procedure.

Step 1: Prepare the window.

Check your window for any damage to make sure that it is in good condition. Measure its dimensions and mark the center point. This measurement guarantees that the flanked panels reach all sides of the room window equally.

Then, fit the panels that come with the air conditioner package into the correct places. Adjust them to ensure that they evenly fit. Secure their places with screws. Make sure that you tighten the screws enough to prevent the air conditioners unit from falling or shaking.

Step 2: Mount the air conditioner unit.

While mini air conditioners can be lifted by one hand, it would be safer to have a couple of extra hands to ensure balance and instability. To mount the unit, begin with opening the window. Lift the unit into the window sill.

Once you have secured the unit into its appropriate place, close the window on the top. Make sure that the huge part of the air conditioners unit hangs outside the room. Close the window tightly to keep the unit secured in place and prevent it from falling or wiggling.

Step 3: Screw the panels and brackets.

After finishing the difficult part of the installation, secure the unit in place. This is done by screwing the L brackets and panels to keep the AC unit tightly in place and prevent it from loosening or moving. If you have a vinyl window in your room, strips of wood can be a suitable replacement for the L-shaped brackets.

If the installation kit comes with padding, add it to the sides of the unit for extra security. After this step, the installation is done. Plug the unit into the power outlet and switch it on. Enjoy the refreshing change in temperature inside your place.

Buying Guide : Things to Consider

Are you still undecided on which window air conditioner to suitable for your room? The wide variety of options available can be overwhelming. So, to help you with your search, here are the essential factors to keep in mind.

Cooling capacity

The cooling capacity or power is an essential consideration for finding the right Air Conditioners unit. If you purchase a unit that is not powerful enough to cool your space, you waste your money and effort.

The cooling capacity is measured in BTUs or British thermal unit. The higher number of BTUs an AC unit has, the larger a room space it can efficiently cool. To give you an idea on the right amount of BTU for several room sizes, here is a simple matrix:


The cost of window air conditioners ranges from around $100 to more than $2,000. The larger the cooling space and the more features a unit has, the more expensive it is. Units in the higher price range tend to cool much larger rooms and come with a significant number of advanced functions and features.

Energy efficiency

Aside from the unit cost, also consider the operating cost. Window Air Conditioners units utilize a lot of energy so they will charge you substantial electric bills. Half of the energy consumption in a household is from the heating and cooling appliances.

Look for Energy Star-rated units as they help you save energy in the long run. The Energy Efficiency Ratio (EER) also indicates energy efficiency. The higher the EER, the more power the unit saves.


One of the significant advantages of window air conditioners is the ease of installation. However, some units require more work than others. You may also avail the optional expert installation service that may come with the unit. Some units come with an installation kit and manual.


One major issue to consider in an Air Conditioners unit is the ease of maintenance. The manual should give you information on how and how often you should clean the unit. Many homeowners recommend units with a removable filter or slide-out chassis for more access to the unit and more convenient maintenance.

The Verdicts

Now that you know the factors to consider in a window air conditioner, it will be easier for you to determine which one is the most suitable for you. If you consider our bestselling list, the Frigidaire FFRA0511R1 might be the best choice because it efficiently cools a standard-sized room and doesn’t come with significant drawbacks. author Anastasia Russell
Anastasia is a 26-year-old blogger who always motivated to observe the ways humans interact with technology. She is currently undertaking a master degree program at the Uppsala University specializing in Human-Computer Interaction & Design Program.
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