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7 Best Energy Efficient Window Air Conditioner

Installing a window air conditioner not only cools your space effectively but also aligns with your eco-conscious lifestyle and saves on energy costs.

Whether you’re looking to reduce your energy bills or make a positive environmental impact, our curated list is your go-to choice for finding the best energy-efficient window air conditioner to suit your needs.

To shortlist the products, we’ve joined hands with HVAC experts and put window air conditioners through tough tests. Our unique evaluation process concentrated mainly on three key factors.

  • EER: Higher EER numbers mean more savings. Aim for an EER of at least 11.8, though our top picks reach up to 15 for maximum efficiency.
  • BTU: More BTUs mean more cooling power, but match the BTU to your room size to avoid excessive electricity use or inadequate cooling.
  • Room Size: For efficient cooling, match BTU to room size: 6,000 BTU suits 200-250 sq ft, scaling up to 15,000 BTU for spaces up to 750 sq ft.

For more insights, you can dive into our comprehensive “Buying Guide” which helps you choose the perfect unit that meets your cooling needs while adhering to your energy-saving goals.

Best Energy Efficient Window Air Conditioner Table

Best Energy efficient window Air conditionerEER RatingBTURoom SizeBuy Now
Midea Energy Efficient Window AC1512000550 sq ftCheck On Amazon
Dreo Energy Efficient Window AC158000350 sq ftCheck On Amazon
LG Energy Efficient Window AC1310000450 sq ftCheck On Amazon
Midea 6,000 BTU Energy Efficient Window AC12.16000250 sq ftCheck On Amazon
Soleus Air Energy Efficient Window AC12.16000275 sq ftCheck On Amazon
LG 12,000 BTU Energy Efficient Window AC12.112000550 sq ftCheck On Amazon
Frigidaire Energy Efficient Window AC11.815000850 sq ftCheck On Amazon

Best Energy Efficient Window Air Conditioner Reviews

1. Midea Energy Efficient Window AC

Midea Energy Efficient Window ACMidea is a leading Chinese manufacturer of home appliances, especially air conditioners. The brand is best known for their innovative and energy-efficient systems and most importantly their competitive pricing.

We are in love with Midea’s smart inverter window AC for many reasons, like it’s EER 15 rated, which makes Midea U one of the most energy-efficient window AC’s on the market today. It’s a 12, 000 BTU unit that can instantly cool down 550 SQ ft area. Its advanced DC inverter motor provides you with better energy savings and makes the operations relatively quiet. At just 42 dB of operating noise, this window AC is also one of the quietest ACs you can find.

With the smart inverter technology, the device can actually control the power consumption and the results are 35% more energy savings. Of course, this increases the initial costs, but in the long run, an inverter AC with 15 SEER rating will definitely reduce your utility bills.

FYI, the AC is Energy star rated and has been certified as the most energy-efficient AC of 2022. As long as the features go, the AC can provide long-distance air-flow up to 20 feet away. It’s WiFi enabled and also compatible with Alexa and Google Assistant.

Unlike most window ACs, which block your entire window for as long as they are installed, Midea U allows you to continue opening and closing of your window. But there’s a catch. The installation process is tricky, and we highly doubt you can install it yourself.

Best Features

  • EER 15 rated
  • 12,000 BTU of cooling power
  • Can cool down 550 sq ft area
  • 42 dB of operating noise
  • Energy Star certified
  • Wi-Fi enabled
  • Compatible with Alexa and Google Assistant
  • Washable air filters


  • Highly energy efficient
  • Smart features
  • Stylish and compact


  • Difficult to install

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2. Dreo Energy Efficient Window AC

Dreo Energy Efficient Window ACDreo is a small scale brand that manufactures mostly air products like tower fans and air conditioners. Their inverter window air conditioner is Energy Star Certified and has received amazing reviews on amazon.

It has an incredible EER 15 rating. With 8,000 BTU of cooling power this small unit can cool down a bedroom or office room of upto 350 sq ft. Infact, it’s also incredibly quiet. At just 43 dB it will keep your room as peaceful as possible.

Dreo smart inverter compressor is made to save 35% more energy which means it will keep your room cool and your electric bills low. It doesn’t come with many features to keep the costs low. Like, there’s no Wi-Fi or Alexa compatibility. Instead, you get a simple remote controller with 5 operating modes, which are auto, cool, sleep, dehumidify, and circulate.

It also comes with a 24-hour timer, allowing you to set a timer at any time of the day. Unlike the Midea U model, it’s simpler to install. It comes pre-assembled. You only need to slide it inside your window and secure it with screws.

Best Features

  • EER 15 rated
  • Energy Star Certified
  • 8000 BTU of cooling power
  • Can cool down a room of up to 350 sq ft
  • 42 dB operating noise
  • Maximum airflow upto 20 ft
  • 24-hour timer
  • 5 modes of operation
  • Comes as pre-assembled


  • Keeps your electricity bills low
  • Low-noise operation
  • Easy to install


  • Sometimes you have to press the buttons of the remote a few times

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3. LG Energy Efficient Window AC

LG Energy Efficient Window ACLG is known for its innovative technology and high-quality products and has become one of the leading manufacturers of air conditioners.

The L.G. 10,000 BTU window air conditioner has an amazing 13 EER rating. It carries the  Energy Star certification, which is a government certification of energy efficiency. So, you can be sure this unit will save on your electricity bills.

It can cool down a space as large as 450 sq ft and produces 52 dB of noise while operating in lower speed settings. While at higher speeds, the noise levels can reach up to 55 dB. To be honest, here. We are not much impressed with its noise performance. L.G. could have done better.

It doesn’t come with lots of bells and whistles like you don’t get Wi-Fi connection or smartphone capabilities, but it gets the job done. It comes with a simple remote controller, which is nice.  The controls are easy to navigate and intuitive. There are 3 fan speeds, a 24-hour timer, and a filter alarm function which is really nice to have.

It also comes with washable air filters, which you can wash with soap and water. It’s pretty low-maintenance. Plus, it comes with everything you need for installing the unit, including side panels and window mounting kits.

Best Features

  • EER 13 rated
  • Energy Star Certified
  • 10,000 BTU of cooling power
  • Can cool down a room of up to 450 sq ft
  • 52 dB operating noise
  • Remote control
  • 3 fan speeds, 24-hour timer, energy saver mode
  • Washable air filter and filter check alarm


  • Easy to install
  • Filter check alarm
  • G reliability
  • 1-year warranty


  • Little on the expensive side

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4. Midea 6,000 BTU Energy Efficient Window AC

Midea 6,000 BTU Energy Efficient Window ACIf you are looking for an AC for your small bedroom or office room, you can go for the Midea EasyCool window air conditioner. It features 8000 BTUs of cooling power, and it’s enough to cool down a space of up to 250 sq ft.

It’s EER 12.1 rated, which is not the highest in terms of energy saving, but it’s not a bad rating either. In fact, it comes with an eco-mode that runs on lower power to save your electricity bills.

Now talking about its noise, it produces around 52 to 55 dB of noise, whereas the Media U had only 42 dB of operating noise, which means it’s going to be louder than its counterparts.

You will love this little champ for the features that it offers. For example, it has 3 operating modes, including a dehumidifier mode and  3 fan speed settings. It has a simple remote control (batteries included) and an LCD. It also comes with removable and washable air filters, which you can easily wash at home. All the mounting kits are included in the package. The installation process is also fairly simple.

Best Features

  • EER 12.1 rated
  • 6,000 BTU of cooling power
  • Can cool down a room of up to 250 sq ft
  • 52-55 dB operating noise
  • Remote control
  • 3 fan speeds, 24-hour timer, eco-mode
  • Washable air filters
  • Mounting kits included
  • 1-year warranty


  • Small and compact
  • Affordable
  • Energy-saving


  • Not ideal for large spaces
  • The remote is too tiny

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5. Soleus Air Energy Efficient Window AC

Soleus Air Energy Efficient Window ACSoleus has 20 years of experience in manufacturing air conditioners, especially window ACs and portable ACs. They are best known for their unique designs, quiet performance, and affordable price tag.

It has an EER rating of 12.1 and a cooling power of 6,000 BTU, which efficiently cools a 275 sq ft area. It’s a great option for smaller size bedrooms, library, and office rooms. It’s small, efficient, and quiet, which is the most important factor for an AC. The noise level it produces is between 38-48 dB making it one of the quietest options on our list.

It’s simple yet user-friendly functions. Like My temperature sensor, which detects your location and shots cool air directly toward you. Besides this, there is sleep mode, 3-fan speed settings, 24-hour timer, and energy saving mode.

Unlike most air conditioners, this easy slide saddle style air conditioner is really simple to install and won’t block your window view. It comes with a simple remote controller and an LCD display for your convenience.

Best Features

  • EER 12.1 rated
  • 6,000 BTU of cooling power
  • Can cool down a room of up to 275 sq ft
  • 38-49 dB operating noise
  • Remote control
  • 3 fan speeds, 24-hour timer, energy-saving mode
  • Washable air filters
  • Saddle style air conditioner


  • Affordable
  • Very easy to install
  • Quiet operation


  • Not ideal for large spaces
  • Doesn’t do much in terms of humidity reduction

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6. LG 12,000 BTU Energy Efficient Window AC

LG 12,000 BTU Energy Efficient Window ACIf you need to cool down a larger room, go for this LG 12,000 BTU smart window air conditioner. It has an EER rating of 12.1, and running this unit will only cost you around 97$ a year (however, this will depend on your use and local utility rates).

The 12,000 BTU power window air conditioner can cool the largest bedrooms and living rooms of up to 550 sq ft. It’s amazing at delivering cool air, it’s efficient, compact, and quiet. It produces around 52 dB of noise while operating in auto mode, and 44 dB in sleep mode.

Coming to its features, L’G has designed this unit with all the bells and whistles. It comes with a simple remote controller with variable modes and fan speed settings, filter check alarm, 24-hour timer, and whatnot. Even more, this unit is compatible with the L.G ThinQ app, which enables smartphone control.

Moreover, It’s compatible with Amazon Alexa and Google Assistant. It’s easy to install and comes with all the mounting kits. What’s more, you get a 1 year warranty from L.G.

Best Features

  • EER 12.1 rated
  • 12,000 BTU of cooling power
  • Energy Star Certified
  • Can cool down a room of up to 550 sq ft
  • 44-52 dB operating noise
  • Remote control
  • 4 fan speeds, 24-hour timer, sleep mode, energy-saving mode
  • Washable air filters
  • G ThinQ App compatible
  • Compatible with Alexa and Google Assistant


  • Can cool down a large space
  • G brand reliability
  • Easy installation process
  • Upto 40% of energy savings


  • It’s not whisper quiet. L.G could have done better.

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7. Frigidaire Energy Efficient Window AC

Frigidaire Energy Efficient Window ACFrigidaire, the American manufacturer that specializes in producing home appliances such as refrigerators, air conditioners, and ovens.

The Frigidaire with 15, 000 BTU of cooling power, can cool down the largest living rooms and bedrooms that you can imagine. It has an EER rating of 11.8 which is great when compared to its size. It has a cooling capacity of up to 850 sq ft, which is an incredibly large capacity.

It’s also Energy Star certified, which means it will use less energy and standard air conditioners, which also means reduced consumption of electricity and less utility bills. It’s also quieter than most standard ACs, especially Windows and portable ACs. It produces around 52 dB of noise on its highest speed settings.

To keep the costs minimum for such a larger window AC, the brand doesn’t provide you with lots of advanced features like built-in Wi-Fi or Alexa compatibility, but it includes all the convenient features like multiple speed settings, 24-hour on/off timer, washable filters, sleep mode with low-running cost and more.

This huge capacity window air conditioner can be overkill if you don’t own an 850 sq ft room. So, don’t just get away with the BTU capacity and cooling power. Buy this only when you have the requirements. Even though it’s Energy Star Certified, running this unit will cost you twice as much as running a 6,000 BTU unit.

Best Features

  • SEER 11.8 rated
  • 15,000 BTU of cooling power
  • Energy Star Certified
  • Can cool down a room of up to 850 sq ft
  • 52 dB operating noise
  • Remote control
  • Multiple fan speeds, 24-hour timer, sleep mode, and eco-mode
  • Washable air filters
  • 1-year warranty


  • Huge cooling capacity
  • Easy to install
  • Multiple variants available


  • Expensive

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Buying Guide

Now that you have gone through the review, you need to understand some important factors so that you can buy the best Window air conditioner for your use and requirements. And for that, we have come up with a Buying guide that goes through each and every factor that you should consider before going for the purchase.

1. EER Rating

The Energy Efficiency Ratio (EER) rating of an air conditioner is a measure of its cooling output (in BTUs) divided by consumption (power) (in watts) and indicates the unit’s efficiency in converting electricity into cooling. In simple terms, it determines the energy efficiency of your air conditioner.

The simplest way to determine your AC’s energy efficiency is to check its EER rating.

The EER rating or Energy Efficiency rating is provided by the manufacturers, but even if it’s not provided, you can always calculate the EERrating of your air conditioner.

Finding the EER rating is very simple, and you can do it yourself. You just have to know two metrics, the BTU of your air conditioner and its power in wattage.

  • BTU Example: 6,000 BTU, 8,000 BTU, 10,000 BTU, 15,000 BTU
  • Power: 800w, 1000 W, 1200 W, 1400 W, 1500 W

EER rating = Cooling capacity (BTU) / Power (Watts)

So, for example, suppose you have a 10,000 BTU of AC, and it’s an 800 Watt power one.

So, the EER rating will be = 10000 BTU /800 Watts= 12.5 EER

Now; your question should be, what is a good EER rating for a window AC?

The simple answer to this is, higher the EER rating, the better the energy efficiency.

The average EER rating of window air conditioners is about 11.5. This means buying a window AC with an EER rating below 11.5 is not advisable. Infact, you should check the ones that have an 11.5 or higher EER rating. The most energy efficient window air conditioners have an EER rating of 15.

2. BTU

BTU stands for British Thermal Unit. It’s a measurement of your AC’s cooling power. BTU refers to the cooling capacity of your unit.

In short, the higher the BTU the more heat your AC will be able to remove within an hour.

Window AC BTU can range from 5000 to upto 30000 BTUs, with 8,000 BTU

being the most used and common.

It’s important to purchase the right capacity AC for your space. Getting an AC with a higher BTU capacity than you need will give you higher electricity bills. Also, purchasing an AC with fewer BTU will be insufficient to cool down your room.

Most models mention their capacity measured in BTU in their description box.

3. Room Size (sq.ft)

Using an air conditioner that is sufficiently powerful to chill a room is crucial. Low powered ACs may not cool down a room properly, whereas a very powerful AC will cause electricity wastage.

So, determine the square footage of your space before choosing the right window air conditioner.

To find out the square footage of your room, measure the width and length of the room and simply multiply.

Then use the following chart to find out what capacity ( Measured in BTUS) window air conditioner  you will need.

Room Size BTU Required
150-200 5000
200-250 6000
250-300 7000
300-350 8000
350-400 9000
400-450 10,000
450-500 11,000
500-550 12,000
550-600 13,000
600-650 14,000
650-700 15,000
700-750 16,000
750-800 17,000

Keep in mind that there may be other considerations besides square footage which might require you to size up a bit, such as high ceilings, position (you’ll want a bigger unit in the kitchen where it can get warmer), and the amount of sunlight the area receives.

4. The Number of Speeds

Always make sure that your window AC comes with multiple fan speed settings. So, you can change the settings according to your convenience. All the window ACs in our list have multiple speed settings. Ensure you have at least 3 adjustable speed settings, if not any higher.

5. Noise Level

Cheaper window air conditioners can be loud, which can rattle and shake your window, making noise constantly. While mid-range and high-end window air conditioners tend to be quieter because they are made with advanced technology.

Most of the high-end models have run-on inverter technology. And sometimes, they have dual inverter systems, which significantly reduces the noise. We have mentioned the noise produced is decibels of all our units. The quiet models in our list produce only 42 dB of noise. For your reference, a normal human conversation produces 60 dB of noise while a soft whisper is only 30 dB.

6. Energy Star Certified

Search for an air conditioner that has the Energy Star certification. This indicates that it satisfies certain energy efficiency standards specified by the U.S. Environmental Protection Agency (EPA) (EPA). Units with an Energy Star rating are usually more efficient than unrated devices.

An Energy star certified AC has higher SEER and EER ratings which are meant to save on your electricity bills.

7. Warranty

Last but not least, remember to look at the manufacturer’s provided warranty. Given that you’re spending so much money on the item, it would be preferable if the manufacturer offered an extended warranty. The compressor is typically covered by a warranty, although some manufacturers do provide a warranty on other parts. Most of our window conditioners listed in this article have 1 year of warranty.

Best Energy Efficient Window Air Conditioner – FAQs

1. What is an energy-efficient window air conditioner?

Ans: It’s an AC unit designed to use less electricity while providing effective cooling, often indicated by a high EER rating.

2. Can energy-efficient window ACs cool large rooms?

Ans: Yes, choose the right BTU capacity for your room size for effective cooling.

3. Are energy-efficient window ACs more expensive?

Ans: They might have a higher upfront cost but save money in the long run through lower energy bills.

4. Do these ACs require professional installation?

Ans: While some can be DIY installed, professional installation ensures optimal efficiency and safety.

5. Can I use an energy-efficient window AC in a room without windows?

Ans: No, these units are designed to vent hot air outside through a window.

6. How often should I clean or maintain my energy-efficient window AC?

Ans: Regularly check and clean filters monthly for optimal performance; professional servicing is recommended annually.

7. Is it worth replacing an old window AC with an energy-efficient model?

Ans: Yes, newer models are significantly more efficient and can reduce energy costs.

8. Do energy-efficient window ACs need special electrical wiring?

Ans: Standard models usually don’t, but check the manufacturer’s requirements for higher BTU units.


So, these were the list of the best energy-efficient window air conditioners. While buying you should consider the EER rating first, then comes the BTU power and then floor area. We hope the buying guide will make your job easier at choosing the best energy-efficient air conditioners.

If you are still confused regarding your purchase, here’s our top three recommendations:

  • The Midea Energy Efficient Window AC is the best energy-efficient window air conditioner overall. With an EER rating 15 it’s highly efficient at energy-savings. It’s 12,000 BTU powered and can cool down a 550 sq ft area. It’s compact, stylish and most importantly incredibly silent.
  • Next comes the Dreo Energy Efficient Window AC, 8000 BTU which is the best budget buy. To keep the costs low it doesn’t come with lots of bells and whistles but its Energy Star certified with EER 15 rating. It’s great for smaller bedrooms and office rooms.
  • The L.G Energy Efficient Window AC is our third recommendation for people who are looking for a higher capacity window air conditioner. With 10,000 BTU of cooling power it can cool down a room as big as 450 sq feet. The installation is simple, the controls are intuitive and you get 1 year of L.G warranty.

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