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8 Best Energy-Saving AC Units, Reviewed. What Is The Most Efficient Air Conditioner?

Repositioning the AC, replacing the filters, and cleaning the compressor, albeit useful, can only do so much if you’re still rocking a decade-old, power hog AC in your home. 

If you really want to save energy significantly and only spend $47 per year keeping your home cool, it’s time to make the switch to the most energy-efficient air conditioner. Plus, get extra benefits like whisper-like operation, smartphone control, and a unique U shape design so you can open the window and let the cool breeze in during colder months. 

8 Best Energy Saving Air Conditioner Units

Our list only consists of energy-efficient air conditioners with EnergyStar labels because they are 10% more efficient than non-certified systems (1). But there is more to an AC unit than having the EnergyStar label – some are only recommended for 150 sq. ft. while others can keep a whopping 1500 sq. ft. room cool. There are also add-on features that you may or may not find beneficial for your needs.

Nevertheless, we’ve covered all the possible air conditioner sizes and features that are suitable for your home. 

Check out this chart to see their features.

Most Efficient Most Efficient Midea MAW10V1QWT U Air Conditioner Midea MAW10V1QWT U Air Conditioner
  • Estimated yearly cost is only $47
  • U-shape design so you can open or close the window
  • Not the easiest to install

Runner Up Runner Up LG LW1019IVSM Air Conditioner LG LW1019IVSM Air Conditioner
  • Dual Inverter Technology
  • Can be controlled remotely via an app
  • Can get loud when set to high

Budget Choice Budget Choice Frigidaire FFRE083ZA1 Air Conditioner Frigidaire FFRE083ZA1 Air Conditioner
  • Gets cold quickly
  • Easy to install
  • Loud noise even on low setting

Haier QHEK08AC Air Conditioner Haier QHEK08AC Air Conditioner
  • 3 Cooling settings and 3 fan settings
  • WiFi-enabled
  • Can be noisy

Keystone ‎KSTAW05CE Air Conditioner Keystone ‎KSTAW05CE Air Conditioner
  • Temperature sensing LCD remote
  • Programmable timer
  • Good for a small room

Whirlpool WHAW242BW Air Conditioner
  • Cools and dehumidifies up to 1500 square feet!
  • Easy maintenance
  • Expensive
hOmeLabs ‎HME030526N Air Conditioner hOmeLabs ‎HME030526N Air Conditioner
  • Multiple cooling settings
  • Use the remote or pair it with your phone
  • Not very quiet

Tosot GJC12BR-A3NRNJ1C Air Conditioner Tosot GJC12BR-A3NRNJ1C Air Conditioner
  • Modern, stylish design
  • Can cool, dry, or be used as a fan
  • Poor installation instructions

Still unsure which is the best efficient AC unit for you? Continue reading to know everything you need to about each model on our list.

1. Midea MAW10V1QWT U Air Conditioner – Most Energy-Efficient AC

Midea MAW10V1QWT U Air Conditioner


  • Estimated yearly cost: $47

  • BTU: 10,000
  • Annual energy use: 500kWh/yr
  • Room size: 450 sq ft.
  • CEER: 15

The Midea MAW10V1QWT U Air Conditioner is the most energy-efficient AC unit you will find in the market today. Compared to other window air conditioners and central air conditioners, Midea’s energy efficiency rating is just 500kWh/yr and the estimated yearly cost is just $47 – that’s huge savings! 

It also cools your room without producing annoying loud noises that you will find in most non-certified ACs. As a matter of fact, this window air conditioner blocks noise from outside. It may seem too good to be true, but it’s all due to Midea’s unique U-shape design. 

Once you install the unit (which can be tricky), you can keep your window closed to block unwanted noise. You can even open the windows and let in the fresh air. That’s right – that unique U shape lets you open your window with your unit installed!

Thanks to the quiet inverter we mentioned earlier, this super powerful AC is incredibly energy efficient. And you can easily control the temperature with voice control or through the app.

The best thing about the Midea is that there is a unit for just about everyone. It comes in an 8000 BTU model or a 12000 BTU model as well. These are just as energy-efficient as the 10000 BTU unit using either 400 or 600 kWh annually. 

With everything that the Midea offers, it’s no wonder it’s our pick for the best energy-efficient air conditioner.

2. LG LW1019IVSM Air Conditioner – Runner Up

LG LW1019IVSM Air Conditioner


  • Estimated yearly cost: $50

  • BTU: 9,500 BTU
  • Annual energy use: 516.3kWh/yr
  • Room size: 450 sq. ft
  • CEER: 13.8

Imagine arriving home every day to find your home at your desired temperature, even in the worst of the summer heat. With the LG LW1019IVSM Air Conditioner, it can be a reality! 

This wifi-enabled air conditioner lets you control your temperature remotely via their app. You can turn it on as you leave the office so that it is nice and cool when you get home. 

Plus, you don’t have to wonder where you left the remote control because you can hook up this energy-saving LG to Alexa or Google Assistant for voice control – I bet your current AC doesn’t let you do that! 

This energy-efficient air conditioner can also help you save money because of its built-in dual inverter. This feature is also responsible for faster cooling time (2).

“Dual inverter systems use twin rotators that provide variable tonnage when removing heat from the air. This allows reaching the desired room temperature faster than conventional A/C.”

So, for homeowners who prefer an AC with minimal cooling wait time, this LG model is a practical choice. Plus, the sleek modern design will look perfect everywhere. You can even pair it with the best energy-efficient curtains to add more style and energy savings to your room.

Putting the AC in ECO mode can further improve its energy efficiency, but this setting is best when temperatures are cooler.  While not quite as quiet as the Midea, the LG is still quieter than most energy-efficient AC units out there. 

3. Frigidaire FFRE083ZA1 Air Conditioner – Budget Choice

Frigidaire FFRE083ZA1 Air Conditioner


  • Estimated yearly cost: $65

  • BTU: 8,000 BTU
  • Annual energy use: 500kW/yr
  • Room size: 350 sq. ft.
  • CEER: 12

Want to cool down your home but not break the bank? Check out the Frigidaire FFRE083ZA1, our budget choice. While it doesn’t have any high-tech features like wifi or voice control, it gets the room cool and does so efficiently.

A budget air conditioner becomes very expensive very quickly if it is not energy efficient. That’s what’s so great about the Frigidaire. This 8000 BTU unit uses less energy and has a better CEER value than the other air conditioners in its class. And it’s available at a great price, making it the best energy-saving air conditioner for the budget-conscious.  

The AC is easy to install and any window. Once in place, you will be impressed with how quickly the unit can cool down a space. And not just a tiny bedroom either. This unit can cool up to 350 square feet quickly. And while it may not be the quietest ac on the market, you probably won’t mind the noise when you see the savings on your monthly energy bill. 

4. Haier QHEK08AC Air Conditioner

Haier QHEK08AC Air Conditioner


  • Estimated yearly cost: $69

  • BTU: 8,000 BTU
  • Annual energy use: 526.3kW/yr
  • Room size: 350 sq ft.
  • CEER: 11.4

The Haier QHEK08AC Air Conditioner has all the smart features of an expensive air conditioner without the steep price tag. It is wifi enabled and connects to Alexa and Google Assistant for maximum AC control flexibility. 

The Haier will cool a medium-sized room up to 350 square feet, just like the Frigidaire. But the Haier isn’t quite as energy efficient. It costs more annually to run the window air conditioner, and the CEER is lower than the Frigidaire. 

And you may find that the Haier is loud. Like, turn Netflix up to full volume loud. 

Basically, this model is about trade-offs. If high-tech control features are essential to you and you want a smart home, the Haier is an excellent choice but at the expense of energy savings. 

5. Keystone ‎KSTAW05CE Air Conditioner

Keystone ‎KSTAW05CE Air Conditioner


  • Estimated yearly cost: $40

  • BTU: 5,000 BTU
  • Annual energy use: 309.9kW/yr
  • Room size: 150 sq ft
  • CEER: 12.1

You don’t need a large AC to cool a small room or an RV. A 5000 BTU unit like the Keystone KSTAW05CE Air Conditioner is just what you need. 

Despite the small size, the Keystone has lots of great features. You can cool, dehumidify, or just run it as a fan, depending on the weather. You don’t even have to wait a long time for the room to cool. 

Since it is smaller, this most efficient RV air conditioner doesn’t produce too much noise. In fact, it is rated at only 49 dB, not much louder than the super quiet expensive models we’ve reviewed.

The best thing about this most efficient RV air conditioner is its energy-saving prowess – it’s an annual energy use estimated at only 309.9 kW/year. While it won’t cool your whole house or apartment, it’s an affordable option if you want to cool a small space.

6. Whirlpool WHAW242BW Air Conditioner


  • Estimated yearly cost: $210

  • BTU: 24,000 BTU
  • Annual energy use: 1747.6kW/yr
  • Room size: 1,500 sq. ft.
  • CEER: 10.3

Are you looking to cool your whole apartment or small house, rather than just one room? Then what you need is the Whirlpool WHAW242BW Air Conditioner

It’s the largest energy efficient window air conditioner on our list – it has 24,000 BTUs of cooling power to cool up to 1500 square feet!

You can use the remote control to set up a 24-hour program for your cooling and dehumidifying needs throughout the day. If planning for the whole day is more than you care to fuss with, don’t worry. 

This window air conditioner has several pre-programed modes to choose from. You can pick the ECO mode and keep costs down while still enjoying a significant cool breeze. Or maybe you would prefer to set in sleep mode – that will gradually raise the temperature while you sleep. 

If the power abruptly goes out during a summer storm, this energy-saving Whirlpool AC unit has an auto-restart function to prevent overheating – as soon as the power’s back, so is your cool air.

However you decide to program it, the Whirlpool is the most efficient window air conditioner for cooling a large space. 

7. hOmeLabs ‎HME030526N Air Conditioner

hOmeLabs ‎HME030526N Air Conditioner


  • Estimated yearly cost: $81

  • BTU: 10,000 BTU
  • Annual energy use: 625kW/yr
  • Room size: 450 sq ft
  • CEER: 12

If you like the features and size of the Midea but not the price tag, you might want to check out h0meLabs HME030526N Air Conditioner. It is less expensive but can cool the same size space up to 450 square feet. 

Aside from the similar cooling capacity, you can easily pair the h0meLabs model with your phone, Alexa, or Google Assistant for easy control anywhere you are. 

So if it has all these features, you are probably wondering why it is cheaper. And the answer is that it is not quite as efficient as the Midea. It will cost you $81 a year to run the h0meLabs unit. But depending on how much you plan to run it, the upfront savings with the h0meLabs may be worth it if you want smart features at a lower price point. 

8. Tosot GJC12BR-A3NRNJ1C Air Conditioner

Tosot GJC12BR-A3NRNJ1C Air Conditioner


  • Estimated yearly cost: $98

  • BTU: 12,000 BTU
  • Annual energy use: 756.3kW/yr
  • Room size: 550 sq. ft
  • CEER: 12

Let’s be honest. A minimalist design isn’t what comes to mind when we think of a window air conditioner. But the Tosot GJC12BR-A3NRNJ1C Air Conditioner isn’t your grandma’s air conditioner. This model features a sleek modern design you won’t have to be embarrassed about. 

The design isn’t the only thing modern about this window air conditioner. It features a smart remote control that senses the temperature where you are at. Then the remote sends a signal to the unit itself to make sure the temperature is optimal – where you are not where the unit is. 

This is an excellent feature because the Tosot is strong enough to cool a sizable space. It has enough cooling power to keep a 550 square foot space comfortable even in the height of summer. 

Easy to install, easy to clean, and easy to use. The Tosot window AC unit has everything you need to stay cool all summer long.

Buying the Best Energy Star Air Conditioner: What You Need to Know

Part of building an energy-efficient home is choosing energy-efficient appliances. But there are other factors to consider to find the best energy-efficient air conditioner for your home. 

You want to consider the size of your room and how many BTUs the unit uses, the CEER rating, your annual energy usage, and cost. You also may want to consider how loud the unit is and any smart features it may have. 

So let’s look at these factors more closely.

When looking for the most efficient air conditioner, the first thing you need to know is where you will put it. And that’s because not all rooms require the same amount of cooling power. Things like size and sustainable insulation options are going to affect how much power you need. 

changing the filter of a split type AC, one of the most efficient air conditioner

No matter what you may think, bigger is not always better when it comes to air conditioning. If your air conditioning unit is too large, your room may wind up feeling damp and clammy. Yuck!

Luckily, it’s pretty easy to know what size ac unit will be best for your room. You simply need to know the room’s square footage. If you don’t already know how big your room is, bust out your tape measure. 

You should measure one long wall and one short wall. This measurement will give you the length and width. Then, multiply these numbers, and voila! You have your room’s square footage. 

Once you have your room’s square footage, you can use that to determine how many BTUs will be enough to keep the space cool (3).

What’s a BTU? I’m glad you asked. BTUs, or British Thermal Units, measure how much heat is contained in an energy source (4).

Here’s a handy guide that you can refer to: 

Area to be cooled Required BTU Best AC Unit
150 sq ft5000Keystone ‎KSTAW05CE Air Conditioner
450 sq ft10000Midea MAW10V1QWT U Air Conditioner
1500sq ft24000Whirlpool WHAW242BW Air Conditioner

Watch this video to see more about how to decide how many BTUs you need.

CEER rating

When looking for an energy-efficient air conditioner, there are many different efficiency measures like seasonal energy efficiency rating (SEER) and Energy Efficiency Rating (EER) out there. But you should also take a look at CEER rating because it measures the AC unit’s efficiency in both standby mode and cooling modes (5). 

“Combined Energy Efficiency Ratio (CEER): The ratio of measured cooling output (in BTU per hour) to measured average electrical energy input (in Watts) and measured standby/off-mode power consumption (in Watts.).”

Because here is the thing with air conditioners, they don’t really turn off even when they aren’t running. They have all the features that still run even in standby mode. But they aren’t consuming the same amount of energy as they do when cooling the room. Since the difference between standby mode and cooling mode is so high, it is hard to figure out energy consumption.

When shopping for an energy-saving AC, don’t just look for Energy Star certified models; You should also check the CEER rating.

The higher the CEER number, the more efficient the air conditioner is. Just keep in mind larger AC units will always have a smaller CEER number, as the chart below demonstrates. It is best to compare the CEER numbers with models that have the same BTU output.

Energy-Saving AC BTUCEER 
Midea MAW10V1QWT U Air Conditioner10,00015
Tosot GJC12BR-A3NRNJ1CAir Conditioner12,000 BTU 12
Whirlpool WHAW242BW Air Conditioner24,000 BTU10.3

Annual Energy Use and Cost

Obviously, annual energy use and cost will depend on how frequently or long you use the air conditioner. For an estimate, you can check the Energy Guide label of the AC. 

These numbers are based on the national average (6). According to the Energy Guide label, the Midea, for example, is estimated only to cost $47 a year to run.

This bright yellow Energy Guide label will tell you everything you need to know about your energy consumption.

If you want to find out your actual usage rather than the national average, use the following formula:

First, determine your daily energy consumption-

Estimated hours per day of usage X wattage / 1000= daily kWh

Now multiply your daily kWh time 365 for your yearly usage

Daily kWh X 365= annual energy consumption

We generally don’t use an AC unit every day, even if you live somewhere really hot. So you can substitute that 365 with the number of days you think you will actually use your AC to get a more accurate estimate. 

Once you know your annual energy usage, multiply that by what you pay your electric company per kWh, and that will tell you how much it costs- for you. 


Most efficient central air conditioners have new tech to keep noise levels down. If noise concerns you, consider the dB level of the air conditioner—the lower the number, the quieter the unit. 

If you are sensitive to noise, you might want to check out a super quiet model like the Midea. It is only 42 dB, making it the quietest energy-saving AC available. On the other hand, if you like a little white noise while you sleep, the noise output may not be significant.

Smart features

While smart features aren’t necessary, they can be convenient. If you are willing to pay a little more, you can get a wifi-enabled air conditioner that will connect with Alexa or Google assistant. Then you can control your AC with voice commands. Many smart AC models, like the LG, also have an app that you can download to control the unit remotely. 


An inverter air conditioner uses an inverter to control how fast the compressor runs. By running the compressor at variable speeds, you can save money on your cooling costs. Non-inverter AC units ‘ compressors can only run at one speed.

A 5000 BTU AC unit is best for a bedroom. When looking for an ac unit, you want to consider the size of the space. Most bedrooms are only around 130 square feet. If you get a unit that is too large, not only will it cost you more money to run, but it may not cool your space as effectively as a smaller unit.

An air conditioner should run for 10-15 minutes to cool your room to the optimal temperature. After that, it should cycle on and off two to three times an hour to maintain that temperature. If it is exceptionally hot out, you may find your air conditioner runs more.

  1. Room Air Conditioner. Retrieved from:
  2. The Advantage Of Dual Inverters In HVAC Systems. Retrieved from:
  3. How To Choose the Right Sized Window AC. Retrieved from:
  4. British thermal units (Btu). Retrieved from:
  5. ENERGY STAR® Program Requirements Product Specification for Room Air Conditioners. Retrieved from:
  6. Shopping for Appliances. Retrieved from: