8 Smallest Air Conditioners for Small Room in 2024

Finding the right small air conditioner for small room settings can be challenging. Here is a comprehensive guide to the best rated window AC’s and portable AC’s made especially for small rooms and/or small open areas.

These are ideal small air conditioners for bedrooms, craft rooms, offices and dens – rooms measuring anywhere from 10’x12’ to 15’x15’ would fit this description. Even a “tiny house”, which typically averages from 100 to 400 square feet could benefit from one of the smaller AC units available today.

Did you know? Both window ACs and portable ACs can also be called a room air conditioner since they’re designed, especially these small room ACs, for a single room.

Let’s begin with brief Overviews of the best rated, then give full Reviews to follow. We will then give you a Buying Guide with both small window and portable air conditioner FAQs. We start with Window ACs and then cover Portable ACs. Use the Navigation Guide, if you’d like, to home in on what type you prefer.

Overviews – Best Small Room Window Air Conditioners

Window air conditioners are those that rest on the sill of a window with about 1/3 of the unit inside the room and the remaining 2/3 outside. Here are brief overviews of 4 of the best, as rated by people who have purchased them and used them in their homes.

Small Room Window Air Conditioner Reviews

Here are complete reviews for the best small window air conditioners for small rooms.

#1 Midea MAW05M1BWT 5,000 BTU Window AC

Highest Customer Rating

This mini-compact window-mounted room air conditioner may be ideal for that small room in your home that could use extra cooling power – maybe if faces west or is far from the central AC blower – either way, this little unit gets top rating as  Best Overall small window air conditioner.

Easy to operate manual controls to allow you to set it to that “just right” temperature.

BTUs: 5,000

Modes: 2 – Air Conditioning and Fan Only

Features: This Midea Window AC is known for:

• Easy Installation
• Convenient manual controls for temperature and fan settings
• Quietness for sleeping
• Combined Energy Efficiency Ratio (CEER) of 11.0
• Washable and reusable mesh filter

Pros: Small, easy to install and operate, this small room window AC has outstanding customer reviews. At well under $200, it’s no wonder it’s a bestseller.

Cons: Limited installation instructions. Air flow can only be adjusted sideways, not up and down.

Bottom Line: A great small-sized air conditioner at a very good price. An abundance of customer reviews averaging 4.5 out of 5 stars. This could be the one that’s right for your small room.

#2 Frigidaire White Energy Star 5,000 BTU Window Air Conditioner

Highest Efficiency

With the coveted Energy Star rating, this small room window air conditioner is more efficient than many others of similar size.

BTUs: 5,000

Modes: 4 – Fan Only, Auto, Cool, Dry

Features: This small AC unit has many you will like:

• Low power start-up and operation for a CEER of 12.1
• “Ready-Select” electronic touch controls and a full-function remote control
• LED Readout
• 4-way air direction control
• Tilt-out filter access with a check filter alert

Pros: This model has many features similar to those found on larger units. The combination of touch and remote controls make it very user-friendly.

Cons: Difficult to find a genuine con for this model.

Bottom Line: The Frigidaire White Energy Star 5,000 has proven itself to be a winner in the areas of both energy efficiency and features.

#3 Keystone KSTAW05BE 5,000 BTU

Lowest Profile and Lightest

BTUs: 5,000

Modes: 4 – Cool, Auto, Dry, Fan Only

Features: This small window AC unit is well-equipped:

• “Follow Me” remote senses the temperature wherever it is
• Multiple modes and fan settings
• Energy Saver and Sleep settings with programmable timer
• Combined Energy Efficiency Ratio (CEER) of 11.0
• Low profile for ease of installation

Pros: The energy saver and sleep settings are both welcome features for many. The slightly lower profile fits in windows that some other room air conditioners won’t.

Cons: Not as quiet as some other units of a similar size.

Bottom Line: This slightly smaller and lighter window air conditioner may be just what you are looking for to keep a small room cool and comfortable, especially if your window opening is lower than average.

#4 Della 048-TL-WAC6K 6000 BTU

Largest Cooling Capacity

BTUs: 6,000

Modes: 4 – Cool, Auto, Dry, Fan Only

Features: This unit has a lot inside for comfort, convenience and programmability:

• Highly adjustable fan speeds, including Auto
• ECO and Sleep settings with programmable 24-hour timer
• Energy Star Rated at a Combined Energy Efficiency Ratio (CEER) of 12.1
• Multi-directional air flow adjustments for more cooling control
• Can remove up to 46 pints of water per day from humid air

Pros: Lots of features for a room air conditioner, cools well and really draws out the humidity.

Cons: A little large for a “small” AC unit, both physical dimensions and weight (53 lbs.).

Bottom Line: Slightly larger than the other units in this review, but the Della 6,000 will cool more space while still operating at a high efficiency ratio.

Overviews – Best Small Room Portable Air Conditioners

Portable air conditioners are self-standing units that sit on the floor of your room with an exhaust hose connected to a window kit. Here are brief overviews of our 4 top rated units.

Small Room Portable Air Conditioner Reviews

If you’d like a unit that sits closer to you, a portable air conditioner might be a good fit for your bedroom, office or other small space.

#5 TOSOT 8,000 BTU

Best Features

BTUs: 8,000 (ASHRAE) / 5,000 (DOE)

Modes: 3 – Cool, Dehumidify, Fan Only

Features: This stylish unit is loaded with features for convenience and comfort:

• Super Quiet with a peak noise level of 49 dB on low
• Easy to install in either horizontal or vertical sliding windows
• Dehumidifier can remove up to 2.3 pints of water per hour
• Child Lock function to prevent unwanted changes to settings
• Touch and Remote controls plus 24-Hour Timer

Pros: High quality, very quiet, easy to install in the window, rolls easily.

Cons: Needs to have a drain hose to handle water in humid weather.

Bottom Line:  With 85% of users who rated this unit giving it 4 or 5 stars, it has a reputation of providing the quality and features many are looking for in a small room portable air conditioner. A TOSOT model made our list of the best 70 Pint (High capacity) Dehumidifiers too.

#6 Black + Decker BPACT08WT

Best Self-Evaporating

BTUs: 8,000 (ASHRAE) / 5,000 (DOE)

Modes: 3 – Cool, Fan, Dehumidify

Features:

• 3 Fan levels plus Auto fan speed when cooling
• LED touch control panel and remote control
• Bucket-less, self-evaporating operation
• Slide-out washable filter
• Sleep setting for quieter, white noise

Pros: Easy to install, accurate thermostat, rolls around easily on casters, nice cooling.

Cons: A bit large and heavy.

Bottom Line: The Black + Decker name is well-known for appliances that meet the needs of today’s homes. This portable AC is one more example, and there are no buckets or floor drains to hassle with.

#7 Amana AMAP101AD

Highest Efficiency

BTUs: 10,000 (ASHRAE) / 6,500 (DOE)

Modes: 3 – Cool, Dehumidify, Fan Only

Features:

• Stylish Gold and Black case to accent any living space
• Touch controls and handy remote control both have LCD display
• The Auto-Swing option moves louvers back and forth to circulate air better
• 24-Hour timer allows you to adjust temperature for when you need it
• Sleep setting automatically adjusts temperature for comfortable sleep
• Removable and washable filter with Clean Filter reminder

Pros: Easy to set up, beautiful design, quieter than a window AC and rolls easily on wheels.

Cons: LED display on the remote does not light up.

Bottom Line: The efficiency of this portable is close to that of many window units, making it a great choice for your small room cooling needs.

#8 SereneLife SLPAC8

Lightest

BTUs: 8,000 BTU (ASHRAE) / 4,000 BTU (DOE)

Modes: 3 – Cool, Dehumidify, Fan Only

Features: Some of the additional extras on this model:

• Quick Setup Guide to get you started quickly and easily
• Sleep setting
• 24-Hour timer
• Cooling mode is auto-activated on powerup
• Removable and washable air filter screen

Pros: Lightweight room air conditioner, good for white noise while sleeping, cools well and easy to install.

Cons: Some users report that the noise level is above what they expected..

Bottom Line: This is the smallest of several models made by this manufacturer. A common comment from users is that it was “money well spent”. Consider this model if you are looking for a small portable AC.

Small Room Air Conditioner Buying Guide

When considering an air conditioner for your small room, it will be helpful if you know some important facts about these two types of units.

Window AC vs Portable AC – How Are They Alike – and Different?

How They Are Alike

• Both window AC’s and Portable AC’s operate on the same basic air conditioning principles: They have a compressor, an evaporator and a condenser through which a refrigerant is circulated in a closed loop, and a fan or two to circulate air.
• Both draw in warm air from the room, cool it and remove moisture from it, then blow it back into the room as “conditioned” air – cooler and less humid than before.
• Both collect the excess moisture – the window unit allows it to run to the back and outside the window; most portable units collect it in a tank to be emptied periodically.
• Both also vent the heat that was removed from the room air to the outside environment.
• Both have many of the same features such as remote controls, LED readouts and programmable timers, to name a few.

This is where the similarities end.

How They Are Different

Window AC Units

• Rest on the sill of a window with about 1/3 of it on the inside of the room and 2/3 on the outside. Generally speaking, the evaporator, which gets very cold, is on the inside of the room, while the compressor and condenser, which get very hot, are on the outside.
• Draw in room air, cool and dehumidify it, then circulate all of it back into the room.
• To cool the condenser, outside air is passed over its coils, then blown back into the outside environment.
• No outside air is drawn into the room, so the room air is cooled more efficiently.

Portable AC Units

• Sit on the floor completely inside the room, with an exhaust hose to connect the unit to the outside by means of a window “kit” that installs in a partially open window.
• Draw in room air, cool and dehumidify some of it and blow it back into the room.
• To cool the condenser, some of the room air is passed over the coils, then blown through the exhaust hose into the outside environment.
• Outside air is pulled into the room (under doors, around windows, etc.) to replace that which was blown through the exhaust hose, so the room air is cooled somewhat less efficiently.

How This Is Reflected in the Product Information – BTU, CEER and Energy Guides

1. Concerning Window Air Conditioners

When looking at window air conditioners, you will see a BTU number and a CEER number on the box. It may also be on the unit itself. It is a yellow Energy Guide Label that is required by law. If you are looking online, it will be in the Specifications.

“BTU” stands for British Thermal Units, and is a measurement of how much energy it takes to heat or cool 1 pound of water 1 degree F at Sea Level – in other words, how much heat energy can be removed from the room each hour. Keep that in mind – the BTU measurement is always per hour, so sometimes you’ll see it written BTU/h or similar.

In short, with an AC unit, the higher the BTU number, the more powerful the AC is.

“CEER” stands for Combined Energy Efficiency Ratio and is a measurement of the ratio of cooling output (in BTU’s per hour) to the average electrical energy input (in Watts) and the power that is used when the unit is in standby/off-mode. This takes into consideration LED displays, timers, clocks and anything else that uses energy even when the unit is not cooling the room. The important fact to know here is that the higher the CEER number, the greater the overall cooling efficiency of the window air conditioner.

2. Concerning Portable Air Conditioners

When you look at information concerning a portable AC, you should see two BTU numbers. The first one will be according to testing standards of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) which has been used for many years. It is no longer considered an accurate rating of the actual cooling capacity of a portable, but will still be allowed to be used on the labeling for a while longer.

The second BTU number will be the number which is according to newer testing standards by the Department of Energy (DOE). Some manufacturers also refer to this rating as SACC (Seasonally Adjusted Cooling Capacity). This second number is the one that rates the cooling ability of the portable AC taking into consideration the fact that because of its design, a certain amount of its potential power is sacrificed to cool warm “make-up” air that is drawn into the room to replace the room air that goes out through the exhaust hose.

In order to more closely compare the cooling power of a portable AC to that of a window AC, be sure to look at the DOE (or SACC) number on the portable. By Jan. 10, 2025, the labels on portable air conditioners will look just like those on window air conditioners, and it will be much easier to compare the two types of units.

Since we are specifically concerned with cooling a small room in this article, all of the small portable units reviewed are “single hose” portables. In larger sizes than these, there are some “double hose” models which are somewhat more efficient.

Sizing an Air Conditioner

By “sizing”, we are talking about matching the cooling capacity or your AC unit – whether a window or portable unit – to the size of the space you want to cool. For an air conditioner to accomplish both cooling and dehumidifying properly, it’s important that it be of a BTU capacity recommended by the manufacturer for the size of your room.

If a unit is too small, it will run for very long periods of time trying to cool the room to the temperature you have set. It may even run all the time and never be able to reach it. This could result in an energy bill that is higher than necessary, and a room that isn’t cool.

If a unit is too large, it may cool the room very quickly and shut off, but not run long enough to remove sufficient moisture from the air. The result could be a cold, clammy room.

Each of the models reviewed in this article has an effective cooling power of between 4,000 and 6,500 BTU, which is what is recommended for small rooms – 100 to 300 square feet or so.

But there are also other factors that may require that you increase the size of the AC unit.

Add 1,000 BTU’s to the size of your AC for each of these conditions concerning your room:

• It gets direct sun in the afternoon and/or evening
• It is on an upper floor
• Three or more people are often in the room at the same time
• It has a ceiling more than 9 feet high
• The room is a kitchen, and the stove or range is used
• It adjoins an enclosed, non-cooled space like an attic or garage
• By following these guidelines, you will be better able to choose the correct size air conditioner for your small room.

Window Air Conditioner FAQs

Q: Why are window AC’s so noisy?

A: All true air conditioners have a component called a Compressor. The compressor does what the name implies – it compresses the refrigerant that runs in a closed loop through the system. When the compressor first engages – “kicks in” – it is often a bit louder than it will be after a few seconds of operation. You don’t hear your car AC because it’s under the hood. You don’t hear a central AC because the compressor is outdoors. You hear a window AC because it’s right there on your window sill – even though the compressor is in the back part, which is outside.

Q: What should I do to maintain my window AC?

A: Many people don’t do anything, and this may shorten the life of your unit. Here are some recommended items that you can do to keep your window AC in great condition.

1.  Wash the filter according to your user’s manual or when you are prompted by the unit. A clean filter will ensure that an adequate amount of room air will be circulating over both the evaporator coil and the condenser, which will help it to function properly for years.
2. Clean the condenser fins if needed. These are on the back (outside) of the unit and are very thin and fragile. Brush them gently with a soft brush to remove dust, leaves or other outdoor debris. Carefully straighten any fins that are bent or flattened.
3. Store the unit during the cold weather season if you can. This is a good time to give it a thorough visual inspection. If you cannot store it, cover it on the outside with an inexpensive cover that can be purchased online or in local stores.

Portable Air Conditioner FAQs

Q: I’m confused about the water that a portable AC unit produces. Do I have to empty something every day?

A: It will depend on the model you have, how humid the air is where you live and how long the unit is running. Higher humidity and longer run times will result in more water. Some of it is used to help cool the unit itself and is evaporated in the process. Excess water will be held inside the unit. Most portable AC’s do not have a “bucket” or tub to empty, but are emptied through a drain hose that you attach to the bottom edge of the unit. Unless you have a floor drain nearby, you will probably need to roll the unit to a door where you can drain the water outside.

Q: What if I don’t have a standard window – can I vent the portable AC some other way?

A: Yes. A standard window kit comes with portables, but kits for other types can be found online and in big box stores. There are several kits available to vent your portable through a sliding window, a casement window, and even through the wall – similar to the way a clothes dryer is vented. These will all require some “handyman” skills, since there are so many variables involved.