2018 Buyer's Guide

The Most Energy Efficient Window Air Conditioners

Investing in an energy efficient window AC can pay off – and it doesn’t take long to see the savings.

2018 Buyer's Guide

The Most Energy Efficient Window Air Conditioners

Investing in an energy efficient window AC can pay off – and it doesn’t take long to see the savings.

by jtanner

Most Energy Efficient For Small Rooms

Friedrich Chill CP06G10B
Friedrich CP06G10B

This 6000 BTU air conditioner has an EER of 11.2 and an estimated year cost of $50 (high setting).

Most Energy Efficient Window AC Unit


This 6000 BTU air conditioner has an EER of 11.2 and an estimated year cost of $49 (high setting).

Quietest Energy Efficient AC Unit

Haier ESAQ406T
Haier ESAQ406T

This 6000 BTU air conditioner has an EER of 12.2 and an estimated year cost of $44 (low setting).

Energy efficient window air conditioning units aren’t just financially smart – they also reduce your carbon footprint and do a better job of cooling your home.

The U.S. Department of Energy estimates that the average household spends 6 percent of its energy use on cooling spaces in the home. Nationwide, that’s about $11 billion each year – and a massive area of improvement that many Americans are eager to decrease.

With the right appliances and energy use, it’s completely possible. One of those appliances is window air conditioners, which have typically had issues with energy efficiency in the past. However, manufacturers in the last few years have made strides in creating efficient, smarter ACs that do a better job of managing energy use and cooling the home.

Today, we’ll look at some of the most energy efficient window air conditioner units available, and why it’s a good idea to get one that’s on the higher side of efficiency. The Department of Energy estimates that switching to a high-efficiency window AC can save you between 20 and 50 percent on energy costs, and doing small, simple things like cleaning and replacing your filters as needed can save even more usage.

“If all room air conditioners sold in the United States were ENERGY STAR® certified, the cost savings would grow to more than $350 million each year, preventing more than 6 billion pounds of greenhouse gas emissions annually,” says ENERGY STAR®, “equivalent to the emissions from over 570,000 vehicles.”

ENERGY STAR® compliant ACs must meet higher standards for energy use and efficiency, but they also save an average of 9 percent less energy. These units may be slightly more expensive than lower efficiency models, but over time, the money saved by less energy use more than makes up for the higher sticker price.

The Most Efficient Window ACs

After researching and analyzing 40 units from manufacturers like Danby, Friedrich, Frigidaire, GE, Haier, Kenmore, LG and more, we found several units that stood out based on their efficiency – as well as overall performance and customer satisfaction.

Although we focused primarily on the EER ratings of each unit, we also took into consideration the industry and customer feedback on each product. For example, if a unit had an excellent EER ratio but poor reviews and feedback, we didn’t include that model in our final analysis.

Finally, we recommended window AC units based on their cooling performance and the size of the rooms being cooled. This means we chose a high-performing efficient AC for small bedrooms (6,000 BTUs), medium-sized rooms (8,000) and large spaces (10,000+ BTUs).

Here are the most efficient window air conditioners based on their energy efficiency ratio, overall performance, industry reviews and user feedback.

  • GE AEM06LX
  • Friedrich Chill CP06G10B
  • LG LW8016ER
  • Frigidaire FGRC1244T1
  • Haier ESAQ406T
  • Danby DAC060EUB5GDB

The GE AEM06LX is our Editor’s Choice for overall performance and efficiency. The Friedrich Chill CP06G10B is ideal for small rooms, the LG LW8016ER is great for medium-sized rooms, and the Frigidaire FGRC1244T1 is our top choice for large rooms. Finally, the Haier model is our pick for the quietest option, and the Danby DAC060EUB5GDB is our budget pick for those looking to buy a solid, efficient window AC at a lower cost.

Why It’s Smart to Go Efficient

Because cooling a home is such a large expense for households, using energy efficient appliances can make a significant difference in energy use, cost and performance over time.

Some of the main benefits to using the most efficient AC units include:

  • lower energy bills: these units have better parts and materials that make better use of energy, which lowers your usage rate and thus, your energy costs
  • improved environmental footprint: using less energy can help reduce the overall energy use of your home, and decrease your carbon footprint in the big picture
  • increased cooling performance: using an efficient unit will cool the same room down quicker than a less efficient model, which means you get more comfortable, faster
  • better quality: models with higher efficiency are typically made with better parts, which means the unit may be quieter than others and will have to run less to cool the air (also see: the quietest portable air conditioners)
  • smarter features: ENERGY STAR® compliant window units must have “smarter” features like an energy-saving mode and automatic reminders to replace the filters, both of which can make a significant dent in the energy you use each year

Understanding Cooling Power

Before explaining how energy efficiency works, it’s important to know how cooling power is measured with window ACs. These units’ power is measured in BTUs, or british thermal units. This is calculated in terms of how much a unit can cool the air around it in an hour.

On the lower end of the spectrum, there are 5,000 and 6,000 BTU units that are meant for small rooms and spaces. On the larger end, you’ll find 10,000 and 12,000 BTU units meant for larger areas like living rooms, offices and master bedrooms. There are also commercial and heavy duty units that go up to 25,000, though they are rarely as energy efficient as smaller air conditioners, so we’ll be focusing primarily on smaller residential options.

So why’s it so important to get the right sized unit for your space? Because a bigger unit isn’t necessarily better.

“In fact, a room air conditioner that’s too big for the area it is supposed to cool will perform less efficiently and less effectively than a smaller, properly sized unit,” says the Department of Energy.

If you buy an efficient 12,000 BTU unit but place it in a small room that’s smaller, it doesn’t matter how efficient that model is – you’re essentially reducing your efficiency because the unit doesn’t match the size of the room.

Instead of focusing on pure cooling power, then, it’s ideal to match your room size to the BTU rating needed to cool that space. The Department of Energy says a general recommendation is about 20 BTUs per square foot, and ENERGY STAR® offers this helpful breakdown of room sizes.

Energy Star Savings Table Air Conditioners


What is Energy Efficiency Ratio (EER)?

Now that we’ve discussed BTUs, we can look at a metric that looks more at the actual efficiency of a window unit.

To find the most energy efficient units, you can look at the unit’s EER number, or energy efficiency ratio. “The EER is the ratio of the cooling capacity (in British thermal units [Btu] per hour) to the power input (in watts),” says the Department of Energy.

The higher the EER, the more efficient the air conditioner.

As an example, let’s say you have an air conditioner that’s rated to 6,000 BTUs, and it takes 600 watts to run. The calculation would be 6,000 divided by 600, which equals 10. This unit’s EER would be 10.

In general, the most efficient window ACs have an EER of 12 or above, though this depends on the size and cooling power of the unit. In general, it’s a lot easier for a smaller 5,000 BTU or 6,000 BTU unit to have that type of efficiency than it is for a 12,000 BTU unit that’s larger, bulkier and requires more heavy-duty parts to cool larger rooms and spaces.

“An air conditioner’s EER rating is best used to objectively compare air conditioners or to do any type of load or engineering calculation,” says Tim at All Systems Mechanical. “Because it is not diluted by additional inputs, the EER value, in my opinion, is the most accurate way to compare two different HVAC units.”

As we’ve discussed in our research on small portable air conditioners, many air conditioners actual cooling power in terms of BTU is often lower in real-life settings, which means the EER should be used as a benchmark more than anything else. A unit with an EER rating of 12 or above will be more efficient than one below the mark, even taking into consideration changes and differences in real world cooling power.

The most energy efficient models are also ENERGY STAR® compliant. To receive this label, an air conditioner must meet higher-than-normal standards for energy use and efficiency. These standards are set by the government and include criteria like:

  • at least 10 percent higher efficiency than government standards
  • better materials and parts for more efficient energy use
  • better performance for consumers nationwide
  • reduced energy costs in order for users to recoup upfront expense of purchase
  • features like energy-saving mode and filter reminders

Manufacturers can meet these and other requirements by assembling window ACs that have higher quality compressors, fans and surfaces that more efficiently use the energy it takes to run the unit.

Click here to learn more about how appliances can earn the ENERGY STAR® label, or view the Key Product Criteria for room air conditioners.

Editor’s Choice: GE AEM06LX


Specification Summary

BTUs 6050
EER 11.2
Estimated Yearly Cost $49
Weight 50 lbs
Dimensions 22 x 18 x 14
Warranty Yes – 1 Year

The GE AEM06LX is one of Consumer Reports’ highest-rated window air conditioners and considers it a Best Buy. And this is no fluke: the GE model is priced at approximately $200 but offers the performance and efficiency of a much more expensive unit.

The AEM06LX is a straight-forward, 6050 BTU fixed-chassis unit that offers an EER of 11.2, enough to be considered ENERGY STAR® qualified. With three cooling speeds, three fan speeds, a remote control and 24-hour timer, this model offers all the basic and intermediate features you need to keep a room consistently cooled down.

The EZ Mount window installation makes set-up relatively easy, though you’ll still want to take the additional steps of using tape or adhesive to seal up any small air leaks. At 53 pounds and a relatively small chassis, the GEAEM06LX is one of the lightest good-performing units on the market, and it’s hard to beat the value you get at this price.

With a limited 1-year warrantyindustry accolades and solid user reviews, the GEAEM06LX is a clear winner for our Editor’s Choice for efficient window air conditioners.

Best for Small Rooms: Friedrich Chill CP06G10B

Friedrich Chill CP06G10B

Specification Summary

BTUs 6000
EER 11.2
Estimated Yearly Cost $50
Weight 60 lbs
Dimensions 20.9 x 18.4 x 14
Warranty Yes – 5 Year limited

The Friedrich Chill CP06G10B is one of the best-selling window air conditioners on Amazon and was recently named the best window unit for small spaces by The Spruce.

With a 6,000 BTU rating, the CP06G10B is ideal for rooms from 150 to 250 square feet, and offers an EER rating of 12.2, making it ENERGY STAR® qualified.

This model comes with everything you’d expect from an up-to-date window unit: digital remote, digital thermostat, 24-hour timer and an auto-restart function that saves previously used settings. Three cooling speeds and an “Auto Air” system maximizes air movement and circulation, which helps keep the unit performing smoothly and prevents hot pockets of air.

The installation kit allows you to use the CP06G10B in a window or through the wall, and an EntryGuard anti-intrusion feature helps make the unit avoid becoming a security hazard. Filter reminders and cleanable, antimicrobial filters make this an easy-to-maintain air conditioner, and with a 1-year limited warranty, you’ll be covered for your first full season of use.

As one of the highest rated window ACs on Amazon, it has plenty of perks, and one of the only downsides is that at 60 pounds, it’s one of the larger 6,000 BTU window units, though its dimensions aren’t as bulky as you may think.

Best for Medium-Sized Rooms: LG LW8016ER


Specification Summary

BTUs 8000
EER 12.1
Estimated Yearly Cost $60
Weight 58 lbs
Dimensions 19.6 x 19.4 x 12.4
Warranty Yes – 1 Year

LG makes some of the most commonly used air conditioners on the market, and their LW8016ER maintains the brand’s reputation and performance well.

It’s received high marks from Consumer Reports – one of the best rated 7,000 to 8,500 BTU options – and it was also named the air conditioner of choice by Wirecutter, who say that this unit is “the window AC you should probably get, especially if it’s for an office, den, or other room where you won’t be sleeping.”

That last remark is due to the LG’s slightly higher-than-average noise rating, which is listed as 54 dbA indoors and 60 dbA outdoors. Though this is slightly louder than what may be comfortable for some users, it’s also not necessarily high enough to turn off most users.

The 8,000 BTU unit is ideal for rooms between 250 and 340 square feet, and the 12.2 EER rating makes it ENERGY STAR® qualified – with all the features of these appliances, such as energy-saving modes, filter reminders and solid performance features.

Two-way air direction and three cooling speeds give you plenty of flexibility in finding your comfort zone, and a digital remote helps you set it and forget from across the room. At 58 pounds, it’s a relatively small size for a 8,000 BTU unit, and the outside has an “anti-corrosion coating” that’s patented by LG. This helps the unit sustain the elements through summer and the rest of the year if necessary.

A one-year parts and labor warranty covers you for early-use issues, but the user feedback on the LG LW8016ER is solid, especially considering the industry average reviews for window ACs – even good ones – can be less than stellar (mostly due to inflated expectations related to cooling performance).

Best for Large Rooms: Frigidaire FGRC1244T1

Frigidaire FGRC1244T1

Specification Summary

BTUs 12000
EER 12
Estimated Yearly Cost $90
Weight 70 lbs
Dimensions 19.8 x 19 x 14.5
Warranty Yes – 5 Year Limited

The Frigidaire FGRC1244T1 is one of Consumer Reports‘ best rated recommendations for window air conditioners, and there’s a reason why: its cooling performance is matched by Wi-Fi connectivity and other “smart” options that make this one of the most efficient and convenient units available today.

At 12,000 BTUs, the FGRC1244T1 is rated to cool rooms up to 550 square feet. It has an EER rating of 12.0, and according to Frigidaire’s corporate website, the unit is ENERGY STAR® qualified. However, the AC is not currently listed on ENERGY STAR®’s website, though the stated EER, if accurate, would place it into ENERGY STAR® compliance.

Where the FGRC1244T1 excels is flexibility and convenience. Download the Frigidaire app and you can control the temperature and settings of your AC from anywhere. Cool your home down before you get to work, or turn the unit off while you’re out at night. You can also control the FGRC1244T1 with Amazon Alexa and Google Assistant, making it one of the most versatile “smart” appliances on the market.

Its trend-setting features don’t stop with function alone; the FGRC1244T1 is sleek and not the eyesore that many large window units appear to be. At 72 pounds, it is large, but this is to be expected with a 12,000 BTU air conditioner.

Slanted airflow features help with positive airflow, and three fan speeds keep things moving when needed, and quiet when you need subtle cooling. Frigidaire employs its Effortless™ Temperature Control to help maintain room temperatures, which also means the unit doesn’t have to work quite as hard to keep consistent.

With all these features, there’s only one drawback: the FGRC1244T1 clocks in at nearly $500, so it’s ideal for homes with larger rooms that don’t mind the higher upfront investment. However, the energy savings of this unit (especially against comparable ACs) can make up for the higher upfront costs.

If you’re looking toward the future of smart cooling appliances, or your home uses Amazon Alexa or Google Assistant, the Frigidaire FGRC1244T1 is an excellent choice to keep your tech-driven home efficient and comfortable.

Best Quiet Option: Haier ESAQ406T

Haier ESAQ406T

Specification Summary

BTUs 6000
EER 12.2
Estimated Yearly Cost $44 (low setting)
Weight 55 lbs
Dimensions 18.1 x 21.2 x 12.4
Warranty Yes – 5 Year Limited

Unlike central air conditioners, room ACs can be loud: because their parts – motor, compressor, fan – are all in or near the space you’re cooling, you can hear them more than if they were entirely outside.

That’s not a problem, however, with the Haier ESAQ406T, our top pick for small bedrooms. This unit is quiet, performs well and doesn’t cost much more than similar units in this category (6,000 BTUs).

“At its lowest fan setting and with the cooling mode turned on, the Haier ESAQ406T runs at just 54.5 dBC,” says Wirecutter. “That’s almost 8 dB quieter than our main pick, a very obvious difference.”

Wirecutter named this model its upgrade pick for bedrooms, and Business Insider named a variation of this model one of its top window ACs available.

Haier claims that this is the quietest window AC on the market based on third-party tests, so if you’re looking for an efficient machine that won’t interrupt your work, study or sleep, this model is hands above the rest.

The ESAQ406T offers an EER of 11.2, which doesn’t qualify it to be ENERGY STAR® qualified, though a similar Haier modeldoes meet those guidelines. However, the ultra-quiet performance of this machine, combined with its relative parts and reputation still make this one of the best picks for an efficient small bedroom AC.

The editors of Wirecutter note that “since window ACs are so tightly regulated by the Department of Energy, we’re confident that it will perform similarly to the 6,000 Btu variants of our main pick and runner-up.”

The ESAQ406T offers four modes: cool, fan, dehumidify and energy-saving mode. A 24-hour timer, remote control and sleep mode make it convenient and easy to keep on a schedule. Haier claims that it cools rooms up to 250 square feet, and ultimately, it’s ideal for small spaces that need white noise to a minimum: bedrooms, home offices and the like.

Best Budget Option: Danby DAC060EUB5GDB


Specification Summary

BTUs 6000
EER 12.1
Estimated Yearly Cost $50
Weight 52 lbs
Dimensions 17.8 x 21.6 x 14.8
Warranty No

If you like the idea of an energy efficient window AC but want to keep your upfront expenses low, consider the Danby DAC060EUB5GDB. It may not be as recognizable of a brand when compared to LG, Frigidaire and GE, but Danby typically offers excellent products (one recommended by Consumer Reports) and this is one of them.

This 6,000 BTU unit is ideal for small rooms up to 250 square feet, and like the other units of this size, it’s ENERGY STAR® qualified with a 12.1 EER. It’s priced to move, but that doesn’t mean it’s cheap: the parts and materials used to make this unit are the same high-quality, energy efficient parts needed for ENERGY STAR® compliance, so it still performs well despite a lower price point.

Electronic controls, a 24-hour timer and remote control give the unit standard convenience, and although there’s nothing that will blow you away (excuse the pun) about this Danby model, it’s a sub-$200 workhorse that gets the job done.

Air circulation is solid with 4-way air direction movement, and an energy-saving mode keeps your costs down while maintaining a comfortable temperature. Reviews on Amazon are above-average for the industry, and the one-year warranty on parts and labor offers standard support as far as window ACs go.

Tips for Further Reducing Your Energy Costs

While operating an energy efficient window AC is a great start, there are other things you can do to reduce your energy use and help your unit perform at an optimal level.

First, try to keep your thermostat as high as comfortably possible. Although this is easier said than done, the difference in temperature between the inside and outside environments will determine how hard your AC has to work.

A small temperature difference of just a few degrees will make it easier for your air conditioner to maintain a good working level, but keeping your room extremely cool while its cool outside will make it work harder.

Next, try to keep your air conditioner’s filters as clean as possible. You may have to replace them every few months, depending on how often it’s used, but you can clean them often to keep the air circulation going strong.

The Department of Energy estimates that not cleaning and replacing your filters appropriately can cost you between 5 and 15 percent more in energy costs.

Finally, when you install your air conditioner, do your best to seal and plug any air leaks in the window and installation kit. Often, you’ll need to use duct tape or another adhesive to really seal all the leaks. Even great window installation kits are still made to fit multiple sizes, so they won’t be “perfect” for your window without a little extra work on your part.

Extra Steps to Help with Indoor Temps

Installing and using your AC properly goes a long way, but you can also reduce the temperature of your rooms to help keep your energy use lower. Some things include:

  • using table or portable fans to increase air circulation and ventilation
  • using ceiling fans to increase ventilation
  • using high-efficiency sun-blocking window curtains and shades
  • avoid using high-heat appliances like stoves, ovens and dryers during warm times of day

To learn more about reducing your home’s energy consumption, visit Sustainability at Harvard or