Smallest Window Air Conditioner

Updated: Nov 14, 2023 9:06 PM
smallest window air conditioner featured image that shows the top three best air conditioner models

When selecting the best air conditioner, a unit’s BTUs (or British Thermal Units) is the first factor to consider, since it indicates the room size a unit is designed to cool with maximum efficiency. The best small window air conditioner is likely going to be in the 5000-6000 BTU class.

Of course, that’s not the only factor when it comes to choosing the ideal fit for your needs. Across the board, small window air conditioners are easy to install, which can often be done by one person. In addition, though basic models often come with fewer additional features, more advanced models may have things such as remote control, LED display, sleep mode, and Wi-Fi connectivity.

If you’re looking to cool a small room of 100-150 square feet, a small window air conditioner in the 5000 BTU class will suit your needs best without stretching your budget or wasting energy. A general rule of thumb for air conditioners is that overall efficiency in an AC unit decreases as BTUs increase, with 5000 BTUs being the most efficient models widely available.

Keep reading our buying guide to learn more about the best small window air conditioners and what they offer.

Best Small Window Air Conditioners

 #1   GE AHEC05AC Air Conditioner


WHY WE LIKE IT: It is ideal for small windows and is very easy to set up. It has mechanical controls and a two-way adjustable louver for good air circulation.

  • Easy to adjust dials
  • Not heavy
  • Compact in size
  • No 24-hour timer

This easy-to-install 5000 BTU GE Air conditioner is perfect for cooling small rooms up to 150 square feet in size. It comes with two cooling and two fan speeds for owners to choose from, as well as a slide-out filter that is pretty easy to clean. The AC unit also has a 2-way adjustable louver for even air distribution and two separate dials that adjust the cooling temperature and fan speed. Unfortunately, it does not come with a 24-hour timer.

The 5000 BTU air conditioner is perfect for keeping the room cool, and weighing only 36 pounds, it shouldn’t be challenging to carry around. Users will also appreciate its compact size since this allows it to fit into various spaces, and since its noise level is also not very high, it should not cause them any disruption.

 #2  LG LW6017R Window Air Conditioner


WHY WE LIKE IT: It has an energy saver function that regulates electricity consumption and is relatively quiet. It also features a remote for convenient operation.

  • Very easy to remove dust filter
  • Quiet operation
  • Comes with a remote for convenient use
  • No dehumidifying function

The LG LW6017R is a 39.6-pound window air conditioner that comes with three cooling and three fan speeds, as well as an auto-restart feature that turns the AC unit back on with its previous settings in case of a power outage. It has a 6000 BTU rating making it perfect for rooms up to 260 square feet, and it also comes with a remote that makes it pretty convenient to use. The AC unit also features an energy saver setting to keep energy costs manageable and a clean filter alert to notify users whenever it is time to make a filter change. Unfortunately, it does not have a dehumidifying function.

With a measured noise output level of about 52 decibels, this window AC unit doesn’t produce a lot of noise, and since it also comes with an easy installation kit, putting it together shouldn’t be very difficult to do. The AC unit has a dust filter that is conveniently placed for easy removal, and with a 24-hour on/off timer, owners will be able to easily program its functioning.

 #3   Koldfront WAC12001W 12000 BTU Window Air Conditioner


WHY WE LIKE IT: It has four different operational modes that include a dehumidifier to rid the air of excess moisture, and it also has an auto function that heats or cools as needed. This could be a contender for the top-rated window air conditioners with heat.

  • Very easy to install
  • 4-way directional louvres for good air circulation
  • Has a 24-hour timer
  • Some might find it noisy

The Koldfront WAC1200W air conditioning unit is a reliable option for anyone with a space that averages up to 550 square feet, thanks to its 12 000 BTU rating. The unit comes with four operation modes and has a 24-hour timer for users to program it according to their desired functioning. It has also got 4-way air directional louvers to guarantee efficient airflow and three fan speeds for users to choose from. Its fan can also be set to operate automatically without being set, but some users might find it noisy. Additionally, it’s not a great small portable air conditioner.

For added convenience, this air conditioning unit comes with a simple-to-use remote that can be used to operate it from a distance, and since it also features a dehumidifier setting, users will be able to dry their space in case there’s a lot of humidity. The air conditioning unit is pretty easy to install on a window since it comes with the required installation kit, and since it comes with an eco-friendly refrigerant, it is not likely to cause any harm to the ozone layer.

 #4   Midea MAW05MM1BWT Window Air Conditioner


WHY WE LIKE IT: It is excellent for small spaces and has knobs to regulate its temperature and cooling functions. It also has a washable filter.

  • Very easy to install
  • Quiet operation
  • Reusable filters
  • No remote control

The Midea 5000 BTU window AC is a 2-in-1 cooling fan that is great for small spaces between 100 to 150 square feet. It has a decent noise level of between 54 to 57 decibels, is excellent for a window size of about 23 to 36 inches, and is very easy to install. It comes with a reusable filter that is as easy to wash as it is to remove, and with seven different temperature settings, users will have a wide variety of options to pick from. The unit comes with easy-to-adjust temperature and cooling dials, but it does not come with a remote control.

The air conditioning unit is also compact and has two cooling and two fan settings, which is a lot like the Forty4 small oscillating tower fan. Its louvers can dissipate air in two different directions for efficient circulation, and since it weighs about 40.8 pounds, it is not that difficult to handle. The AC unit is also energy efficient, so users shouldn’t have to worry about their energy bills rising.

 #5   Frigidaire FFRA051WAE Window Mounted Room Air Conditioner


WHY WE LIKE IT: It is very easy to use thanks to its two knobs and comes in a compact, space-saving design.

  • Very easy to use
  • Comes with a rewashable filter
  • Two-way louvres for circulation
  • No remote

The Frigidaire FFRA051WAE is a 5000 BTU window-mounted air conditioner with an airflow efficiency of 136 cubic feet per minute per watt. It weighs about 35.27 pounds and comes with an easy-to-clean washable filter. If the power goes out while still in use, owners won’t have to reset it since it will automatically revert to the previous settings. It has two two-way air louvers for efficient air circulation, but its lack of a remote may discourage some from buying.

Installing this AC unit is pretty thanks to its adjustable side panels. They are meant to extend to best fit the window, making it a lot more flexible to deal with than other units. The AC unit also has a long power cord for convenient placement and offers two working modes for users to be able to quickly fan or cool their space.

 #6   Amazon Basics Window Mounted Air Conditioner


WHY WE LIKE IT: It is ideal for users that want a reliable Air Conditioning device that is easy to operate and can be placed in the bedroom or office. It comes with washable filters and is easy to install.

  • Easy to install
  • Easy to operate
  • Comes with washable filters
  • Does not come with a remote

This Amazon Basics window-mounted air conditioner is efficient for cooling 150 Sq ft spaces and is very easy to operate since it only features two knobs that separately control temperature and its fan. The AC unit offers seven different temperature settings and an inbuilt filter that is pretty easy to remove and rewash. This air conditioner also comes with a window-mounting kit for easy installation, and its louvers allow for two-way air circulation. However, buyers might have to contend with the lack of a remote.

The AC unit will easily fit standard windows with a minimum window height and width of 13 x 23 inches and a maximum height and width of 36 inches. It also has a 6.5-foot 3-prong power cord that gives users added flexibility in terms of placement and a window-mounting kit that is also easy to put together.

Beginner’s Guide to Small Window Air Conditioners

What Is a Small Window Air Conditioner?

A small window air conditioner is a 5000-8000 BTU air conditioning unit designed for easy installation in windows anywhere from 16 to 20 inches wide (and sometimes wider) and around 14 inches high. These window units are designed for efficient, quick cooling of rooms approximately 150-350 square feet in dimension with low or average ceiling height.

Many come with temperature controls that are easily adjustable to your desired comfort level, and they’re easy to install by simply setting them on a window sill. Furthermore, these window air conditioning units provide greater flexibility than central air units in terms of installation and placement, as well as providing more precise temperature control. This means that you can find the right AC temperature for winter and other seasons.

Most small bedrooms, bathrooms, and living rooms are a good fit for air conditioners in this BTU class, but to be sure that you purchase the right model for your space, you’ve got to match the BTU output of a model with the square footage of your room.

This is an important factor to consider when buying a powerful device like an air conditioner, as the power consumption can be vast. Make sure you get one with maximum power that won’t strain your electricity bills.

A 7000 BTU model will technically cool a 200 square foot room, but it may take longer than you’d like and with a loss of efficiency that you’ll feel in your power bill. In this case, an 8000 BTU unit may be the better choice, though they’ll come with a slightly higher price tag. That should be mitigated by the increased efficiency of the room size, but be mindful of this if you’re on a tight budget.

Also, keep in mind that a room with high ceilings or an unusual shape that has poorer air circulation may need an air conditioner that’s slightly more powerful than the actual room dimensions would seem to call for. In other words, a 100 square foot room with extra high ceilings may require a 7000 BTU unit for the most efficient, fast cooling, where otherwise a 5000 BTU unit would do. The same principle applies to kitchens, where ovens and other kitchen appliances create regular ambient heat that makes the room harder to cool.

Regardless, it’s important to remember that an air conditioner that’s more powerful than the space requires will waste energy but cool a room faster, while an air conditioner that’s underpowered for the space it’s cooling will also waste energy, and cool a room more slowly. While modern air conditioners have a high energy efficiency rating, the actual performance is dependent on the size of the space, as well as the air temperature and dehumidifier mode that’s used.

Small Window Air Conditioners vs Other Models

Small window air conditioners in the 5000-6000 BTU range have some important differences compared to larger, more powerful models, such as the high-end 15000 BTU window air conditioners. The foremost difference, besides a lower price point, is that smaller models are more energy efficient.

Whether conventional, the best ventless portable air conditioner, or inverter models (the latter of which use advanced compressor technology to provide efficiency and performance superior to that of conventional units), 5000 BTU air conditioners are by far the most efficient class of window air conditioner you’ll find.

This includes models with sub-5000 BTU cooling capacity, the majority of which are portable air conditioners that run on batteries. If you’re considering a portable unit to cool your small room, know that you’ll be sacrificing efficiency and performance for minor convenience. Portable models are also often as expensive as 5000-6000 BTU units, meaning they’re not really a good option for the budget-minded, either. Keep in mind that there are also versatile units out there where they can be both a window AC and also a portable unit like the one we discuss in this Costway portable air conditioner review.

Another major difference between 5000-6000 BTU models and others is that many smaller A/C units tend to be basic with fewer additional features. Advanced models that come with Wi-Fi connectivity, remote control, LED displays, sleep mode, 24-hour mode, and other quality-of-life features are less common in this class and usually come at a higher price tag.

Finally, smaller window units are generally noisier than higher-BTU models, except for inverter or dual inverter models. This may be an issue if you’re a light sleeper and looking for a unit for your bedroom, for example. Again, this can vary quite a bit from model to model within this class and may be something you’ll have to refer to online reviews or salespeople to learn about.

Finally, factors like a model’s Energy Star status and EER (Energy Efficiency Ratio) rating can make a big difference in efficiency from unit to unit. The best inverter air conditioner in the 5000-6000 BTU range will be far more efficient at a higher price point than conventional models.

How Small Window Air Conditioners Work

Small window air conditioners work just like all air conditioners, by pulling heat and humidity from a room and replacing it with cold air until the desired temperature is reached. They do this using a refrigerant chemical that works in conjunction with three primary components: a condenser, a compressor, and an evaporator coil.

The refrigerant gas passes through the AC unit, where it’s converted to a liquid as inside air is blown outside. Outside air is pulled inside as the refrigerant is converted to a liquid, cooling the evaporator coil, which cools the outside air as it passes through the unit and fills the room. The refrigerant is then converted back to gas form while inside and outside air continue to cycle through the unit, and the cycle continues until the room reaches the desired temperature.

Why Should You Buy A Small Window Air Conditioner?

If you need to cool a room-sized 100-250 square feet with normal dimensions, a small window air conditioner will do the job with maximum efficiency and speed, with an initial price tag suited to most budgets. Keep in mind that 5000 BTU units are designed to cool 100-150 square foot rooms, while 6000 BTU units are designed for 150 to 250 square foot rooms, and that rooms with high ceilings or kitchens of 100-150 square feet may not cool as efficiently with a 5000 BTU unit.

If your budget allows, you may want to choose a pricier model that offers additional features, such as 24-hour mode, remote control, and WiFi connectivity. However, for an upgrade in performance and efficiency, a small window inverter air conditioner in the 5000-6000 BTU range will offer superior cooling speed and efficiency to any conventional unit and significantly lower your power bill, but with a higher cost of entry.

Is a Small Window Air Conditioner Worth Buying?

  • You need to cool a room of 100-250 square feet: A 5000 BTU unit is the best choice for performance and efficiency in a normal room-sized 100-150 square feet, while for a room of 150-250 square feet, a 6000 BTU or 7000 is the best option.
  • You need to cool a small kitchen: Kitchens are harder to cool due to the heat created by ovens and other appliances, so a small kitchen sized 100-150 square feet is better served by a 6000 BTU unit instead of a 5000 BTU unit.
  • You’ve got a small room with high ceilings: The same rule of thumb applies to rooms with high ceilings as it does to kitchens. A 100-150 square foot room will be more efficiently cooled by a 6000 BTU unit.
  • You’re on a budget: It may be tempting to get a higher-BTU unit thinking it’ll cool a room smaller than it’s rated for quicker, but not only will you be looking at a higher price tag, but you’ll also be wasting energy where a 5000-7000 BTU model would be sufficient, meaning a higher power bill without any real benefits.

Why a 6000 BTU Unit May Not Be For You:

  • You Need To Cool Large Rooms: If you’re cooling a space bigger than 250 square feet, a 5000-6000 BTU unit generally won’t be sufficient. Using one will mean higher energy costs and even a shorter lifespan since the unit will be working harder than it would be in the room size it’s designed for. For example, if you have a space the size of 450 square feet, you should opt for a 11,000 BTU unit like what we discussed in our Honeywell MO10CESWK review.
  • You’d like more advanced additional features: While 5000-6000 BTU units are more efficient than larger models, they also tend to have fewer extra features, such as remote control, mobile device and Wi-Fi connectivity, and multiple programmable modes. If your budget allows for it, you may want to look at a slightly higher BTU class, keeping in mind that an overpowered AC unit will raise your power bill without significant benefits. Additionally, if you wish to have a smart AC, you can use a converter like the one in our Sensibo Sky smart air conditioner controller review. But, keep in mind that more advanced features often require troubleshooting when things don’t work, especially if you find yourself wondering, “What is the E1 error code?”
  • You’re cooling a medium-small kitchen or high-ceilinged room: If you’re looking to cool a kitchen or room with high ceilings with dimensions of 200 square feet or more, even a 6000 BTU unit may struggle to do the job efficiently, increasing wear and tear on the unit, rising energy costs, and providing inferior performance. Plus, if you’re frequently on the go, you’ll want to opt for a small portable unit, such as the one in our Nexgadget portable air conditioner review.

How Long will a Small Window Air Conditioner Last?

Most conventional AC units in any BTU class have a lifespan of around 10 years. Small window units in the 5000-6000 BTU are the most efficient air conditioners, like the best 6000 BTU air conditioner, whether conventional or inverter, and if they’re used for rooms that don’t exceed their size range, they could last a bit longer than that with proper care.

Here are the biggest factors in the lifespan of an air conditioner:

Amount of Use

An air conditioner that’s used every day and/or throughout the year will necessarily have a shorter lifespan than one used only seasonally or intermittently. Inverter AC units have a big advantage here regardless of BTU class and are a good option if the lifespan is a concern for you.

Cleaning and Maintenance

An air conditioner that’s kept cleaned and is regularly maintained will last longer than its filters are never cleaned or replaced and has malfunctioning parts that don’t get repaired. Clogged filters make an AC unit work harder to cool the evaporator coil and cycle air, increasing wear and tear on all components. Regular upkeep is key to keeping your AC unit running for a long time.

Direct Sunlight

Constant exposure to direct sunlight will overheat an AC unit’s chassis and make the components work harder to cool a room, increasing wear and tear and decreasing the life of the unit. In that case, you may want to consider top-through-wall ACs, so you have more options for installation.

If possible, install your AC unit in a north-facing window with as much shade as possible. This isn’t as big a factor as the amount of use and upkeep, but an AC unit used year-round in direct sunlight will definitely feel the effects. Also, if you’re using it year-round and you’re sensitive to noise, opt for the quietest wall air conditioner.

How to Choose the Best Small Window Air Conditioner

Now that you’ve decided to purchase a small window air conditioner, consider a few additional factors and features that will help you choose the right model for you.

Small Window Air Conditioner Key Factors

1. What Is Your Room Size?

5000-6000 BTU air conditioners cool small spaces with maximum efficiency. A 5000 BTU unit is designed for 100-150 square foot rooms, while a 7000 BTU unit is designed for 150-250 or sometimes 300 square foot rooms. If you need to cool a space with bigger dimensions, or a kitchen or high-ceiling room near the higher end of those dimensions, you’ll want to go to a higher BTU class for the best performance and efficiency. In fact, you might want something more portable, like an air cooler. But in such a case, you’ll need to know about air cooler operation.

2. Do You Need Additional Features?

Features like WiFi connectivity, 24-hour auto mode, remote control, and LED displays are great to have but are less common in lower-BTU models. If you’ve got the budget and prioritize such features, you’ll either want to choose a higher-priced 5000-6000 BTU model or take the hit to the efficiency of a higher-BTU model. You can also check out our comparison of a dehumidifier vs an air conditioner if you need to remove moisture from your room.

3. Are Energy Savings a Priority?

5000 and 6000 BTU AC units are by far the most efficient window air conditioners by cooling capacity, but within their BTU classes, there are two standardized measures of efficiency to look for:

  • Energy Efficiency Ratio: Energy Efficiency Ratio or EER in air conditioners indicates BTUs per watt of power. The higher the EER rating, the more efficient an AC unit is. The U.S. Department of Energy recommends models with an EER rating of 10.0 or higher for an optimal cost-to-performance ratio. Plus, make sure the AC capacitor is also working to keep costs low.
  • Energy Star Certified: Air conditioners with an Energy Star certification are guaranteed to use a minimum of 10% less energy than comparable models, lowering your power bill and carbon footprint simultaneously. The majority of U.S. states offer rebates on Energy Star-rated models, which makes them an easy choice for budget and ecologically-minded consumers. But, this rating only makes sense so long as it’s properly installed, which means you’ll want to learn window AC unit sealing techniques.
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