Those who live in older homes without the comfort and convenience of central air understand just how hard it can be to sleep in a hot bedroom in the midst of a heatwave. While a fan can help, a better solution is a small window air conditioner. These diminutive but mighty appliances produce around 5,000 BTUs of energy, which is enough to cool most bedrooms. They are smaller than larger units and capable of fitting in window openings as narrow as 21 inches wide and 14 inches high while also being much more affordable.
Small air conditioners range from top-of-the-line models with LED displays, remote controls, fancy operating modes, and even smart technology, to budget-priced models with simple analog controls. With so many options on the market, it can be difficult to determine which model is the right one.
This guide will examine the factors to consider when choosing the best small window air conditioner and review some of the best models on the market.
- BEST OVERALL: GE AHQ06LZ Window Air Conditioner
- BEST BANG FOR THE BUCK: Emerson Quiet Kool 5,000 BTU Air Conditioner
- BEST FOR SMALL WINDOWS: MIDEA MAW05M1BWT Window air conditioner
- BEST FOR LARGER ROOMS: Koldfront WAC6002WCO 6050 BTU Window Air Conditioner
- BEST AESTHETIC: Soleus Air Exclusive Over the Sill Air Conditioner
- BEST QUIET: Midea U Inverter Window Air Conditioner 8,000BTU
- ALSO CONSIDER: TCL 5WR1-A window-air-conditioner, 5,000 BTU
What to Consider When Choosing the Best Small Window Air Conditioner
Selecting the right size and cooling capacity to meet the needs of the room is the most crucial element when selecting a small window air conditioner. However, other features are also important, including energy efficiency, temperature controls, and the number of operating modes.
Purchasing the proper size to suit the space is perhaps the most critical factor when shopping for a window air conditioning unit. Too small and the air conditioner won’t be able to cool the space to the desired temperature. Too large and the air conditioner will waste energy.
An air conditioner’s cooling capacity is given in British Thermal Units (BTUs), which is a measure of energy output. Window air conditioners range from 5,000 BTUs to over 20,000 BTUs. To determine what size is right for a particular room, match the BTU output to the square footage of the room. A 5,000-BTU air conditioner unit can handle up to 150 square feet, while an 18,000-BTU unit will cover up to 1,000 square feet. Most small window air conditioners range between 5,000 and 6,000 BTUs.
When selecting an air conditioning unit, it’s essential to make sure it can fit the window opening. Most small air conditioners can fit window openings from 22 inches to 34 inches wide with a minimum vertical opening of around 14 inches.
Window mount air conditioners have different types of controls for temperature settings. More affordable models have analog controls with temperature settings that range from 1 to 9, with 9 being the coldest.
Higher-end models have a digital or LCD display with precise controls that allow the user to set the air conditioner to specific temperatures, typically ranging from the low 60s to the mid-80s. These window air conditioners have thermostats built into the main unit that read the temperature in the air and then use the results to regulate when the air conditioner turns on and off. Some models have thermostats in a remote control, which allows the unit to read the temperature in other parts of the room to more evenly cool a space.
Filter and Vents
Window air conditioners have filters that fit behind the slatted air intake on the front of the unit. These filters not only remove impurities that could harm the inner mechanical pieces in the air conditioner but also filter out air impurities, such as pollen, dust, and even some viruses, making the air in the room cleaner. These filters should be cleaned periodically by removing them and rinsing them under a faucet to remove the collected dust and dirt.
After the air in an air conditioner passes through the filter and is cooled in the condenser, a blower sends the chilled air back into the room through the vents at the top of the unit’s face. These vents are adjustable in four directions, allowing the user to make adjustments to the airflow from the air conditioner to evenly cool the room.
All air conditioners remove humidity in the room simply by cooling warm, humid air via the compressor. A dehumidifier function uses the compressor just enough to remove moisture from the air by cycling the compressor on and off. While this mode won’t lower the temperature in the room, it does make the air dryer and thus more comfortable. And since the compressor isn’t running full time, as it does in cooling mode, the dehumidifier mode uses less energy, making it a more economical way to make a room more comfortable.
Air conditioners use a significant amount of energy to operate the condenser that cools the air that passes through it. Depending on its size, a window AC unit will use between 500 and 1,500 watts of electricity. If a small 500-watt window air conditioner runs for 8 hours a day, that translates to 120 kilowatt-hours of electricity each month. Considering the national average cost per kilowatt-hour of electricity is 12 cents, that translates to about $15 a month to cool a single room. Larger AC units will cost more.
Some window air conditioners are more efficient than others. The best way to compare models is to calculate an air conditioner’s Energy Efficiency Rating (EER) by dividing its BTU output by its wattage. The higher the number, the more energy-efficient the air conditioner is. For example, a 12,000-BTU air conditioner that uses 1,200 watts would have an EER of 10 (12,000/1,200). An energy-efficient air conditioner has a rating of at least 9 or above. Energy Star-rated air conditioners have an EER of at least 12.
Window air conditioners include various operating modes and features that make them versatile, more energy-efficient, and easier to use.
- Timers: Many units feature 24-hour timers that automatically turn them on or off after a certain amount of time has passed. This allows the user to set the AC unit to turn off while not in use, saving energy and money, or to turn it on to make sure the space is cool when it’s time for bed.
- Modes: Many air conditioners include various modes that allow the user to fine-tune how they operate. These include energy-saver modes that cycle the compressor off and on to save energy, sleep modes that slowly increase the temperature a few degrees through the night to account for the natural decline in body temperature during sleep, and turbo modes for quickly cooling a hot space.
- Smart: High-end smart air conditioners are able to connect to a home’s Wi-Fi network, allowing the air conditioner’s temperature and modes to be controlled remotely via a smart device or even a digital assistant.
Unlike central AC units, which have their noisy compressors outside the home and air handlers tucked away in the attic space, window units have both pieces in a box that rests in a window. This means the noise of the unit is not muffled by walls.
The average window air conditioner produces about 60 decibels of noise; this is about the same volume as a normal conversation or an electric shaver. Some AC units have quiet options capable of dropping their noise output close to 50 decibels, which is similar to the sound of light traffic. Just keep in mind, the window AC unit is louder when working at or near its capacity, so it won’t produce as much cold air in quiet mode as it does in turbo mode.
Some window AC units feature innovative designs that muffle the sound of the condenser, reducing their noise output to around 40 decibels.
Of all the types of air conditioners—central, through-the-wall, and ductless—window air conditioners are by far the easiest to install. They don’t require cutting holes in a wall, complicated wiring, or brazing copper pipe fittings. Installation typically involves placing the unit into a window using a mounting kit that includes brackets that attach the air conditioner to the window sash and jamb.
Since window units don’t take up the entire width of the window opening, they include adjustable plastic panels that fill the voids in the window on either side of the unit. Weatherstripping installed between the sash, sill, jambs, and air conditioning unit help prevent air from escaping around the unit.
Our Top Picks
The list below consists of the best small window air conditioners on the market. It includes basic models for the budget-minded, efficient units with Energy Star certifications, and advanced air conditioners with cutting-edge technology. Any of the air conditioners below is a good pick for making a bedroom more comfortable in the summertime.
Enough power to handle most bedrooms along with controls that take the mystery out of setting the temperature make this window air conditioner one of the best all-around models on the market. Its 6,000-BTU output sets it just above the power envelope of most smaller air conditioning units, which have 5,000 BTUs, giving it just enough extra oomph to cool spaces up to 250 square feet.
The controls for this AC unit are also an upgrade. A digital display allows for precise temperature settings, and a remote control adds convenience. While this model isn’t Energy Star rated, it just misses the mark with an energy efficiency rating of 11. Despite its larger compressor, this model is compact and able to fit windows as narrow as 21.875 inches wide with a minimum opening of 13.375 inches.
For those on a budget who don’t need all the bells and whistles that come with higher-priced models, this window air conditioner from Emerson is an excellent option. While it doesn’t boast some of the operating modes and features of other higher-priced air conditioners, it does have a 5,000-BTU energy output, which is enough to cool a 150-square-foot room, making it ideal for smaller bedrooms.
Two rotating knobs allow the user to adjust the temperature of the unit from 1 to 7 or set it to fan-only mode. Both cool and fan modes offer two speeds. Louvers allow the airflow to be adjusted in four different directions. It will fit in windows as small as 17 inches wide with a minimum window opening height of 13 inches. At 50 decibels, it’s also one of the quieter window units on the market.
With its compact size, this window air conditioner from Midea is a great option for smaller windows that don’t open wide enough to handle larger models. This window air conditioner measures just 16 inches wide, 13 inches deep, and 12 inches high, allowing it to fit a window with vertical openings as small as 13 inches and as wide as 16 inches. Despite its diminutive size, it packs a punch with a 5,000-BTU energy output that allows it to cover up to 150 square feet.
While not Energy Star certified, its 11 energy efficiency rating makes it one of the more cost-conscious window air conditioning units on the market. A rotating knob adjusts temperatures between 1 and 7 while a second knob allows the user to toggle between two fan-only speeds and two cooling fan speeds. The reusable filter, which catches pollen, dust, and other contaminants, is easy to remove for periodic cleaning.
Larger bedrooms require a little more muscle than what most small window air conditioning units have to offer. With its 6,050-BTU output, this model from Koldfront can cool spaces up to 250 square feet, making it ideal for grander rooms. However, with this air conditioner, a higher energy output doesn’t necessarily mean a higher electric bill, which is evident in its Energy Star certification.
Despite its high output, it is compact at 18.5 inches wide, 15.75 inches deep, and 12.75 inches high, making it capable of fitting a minimum window opening of 14 inches high with a width between 22 inches and 36 inches. The “follow me” mode uses the remote control as a temperature sensor, allowing the air conditioner to evenly cool that larger space. Other operating modes include energy saver, sleep, auto shutoff, and dehumidify.
For those who just aren’t willing to compromise the view from the window for cool air, there’s this innovative model from Soleus. Rather than sitting on top of the window jamb, this air conditioner straddles it, placing the bulk of the unit below the window and preserving most of the view.
This design also keeps the compressor noise outside, making it 30 percent quieter than other window air conditioners. In addition, it’s one of the more powerful small AC units on the market, pumping out 6,000 BTUs of energy. A digital display and remote control that senses the surrounding temperature help create an even temperature throughout the room. Other modes include a sleep mode and dry mode. Keep in mind, though this unit doesn’t take up much window space once installed, it does require a minimum opening of 16 inches to allow for installation.
With its innovative U-shaped design, this air conditioner solves one of the biggest gripes about window air conditioners—noise. Rather than fit in the window space, requiring the window to be open a foot or more, this 8,000-BTU model straddles the window, allowing it to close between the blower and the compressor. With the noisy compressor on the other side of the glass, this air conditioning produces 42 decibels, slightly noisier than a library.
This design also has the effect of creating a much tighter seal between the window and the outside, making it 35 percent more energy efficient than standard window units (which helps to offset its significantly higher price tag). In addition to having all the requisite modes of a higher-end air conditioner, including sleep, energy saver, and auto shutoff, this model is also a smart device, capable of connecting to a home’s W-Fi for control via a smart device or virtual assistant.
This small but mighty air conditioning unit pumps out sufficient cold air to meet the needs of the average-size bedroom while offering enough options for managing the temperature and airflow in the room. A knob adjusts the cooling output from a range of 1 to 7, and four operating modes allow the user to run the air conditioner at two fan speeds with cooling and two fan speeds without cooling.
An easy to access filter removes dust, pollen, and pet hair from the air. With its compact size of 15 inches wide, 16 inches deep, and 12.5 inches tall, the model is one of the smaller air conditioners on the market and will fit window widths ranging from 23 to 36 inches with a minimum vertical opening of 14.5 inches.
FAQs About Small Window Air Conditioners
Proper installation and maintenance of a small air conditioner are vital to keeping it performing efficiently. Ahead, learn more about how to get the most out of these appliances.
Q. Is a window AC the same as a room AC?
Window and room air conditioners differ in the way they vent hot air. Portable room air conditioners are freestanding appliances, often resting on wheels and requiring a hose that attaches to a window to vent hot air outside. A window air conditioner mounts inside the window, allowing it to vent hot air directly through the window.
Q. Is a small air conditioner energy efficient?
Many small air conditioners are very energy efficient, with energy efficiency ratings that are 11 or above. The most efficient small air conditioners have an Energy Star rating, which means they have an EER of at least 12.
Q. How do I make my window air conditioner airtight?
While there are many options for sealing the space around an air conditioner, the best way is to use adhesive-backed weatherstripping to cover the spaces around the air conditioner and the window. You can also use rope caulk, which is similar in consistency to clay, to fill small gaps.
Q. How do you clean window air conditioners?
Use the following steps to clean a window air conditioner:
- Begin by unplugging it.
- Remove the case using a screwdriver.
- Clean the drainpipe pan with soapy water to prevent mold from growing on it.
- Use a vacuum to remove any dust or dirt that has collected inside the unit.
- Spray the inside of the unit with a mild water and dish detergent solution, and wipe with a clean cloth.
- Open the case that covers the exterior side of the air conditioner, and spray and wipe clean the condenser coils.
- Reassemble the air conditioner, then remove and clean the reusable filter.