The 9 Best Energy Efficient Window Air Conditioners

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Written by Leigh Matthews, BA Hons, H.Dip. NT

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Leigh Matthews, BA Hons, H.Dip. NT

Sustainability Expert

Leigh Matthews is a sustainability expert and long time vegan. Her work on solar policy has been published in Canada's National Observer.

Updated:

Our top picks for energy efficient window air conditioner units that are quick and easy to install when summer temperatures get out of control.

Table of Contents
  1. Air conditioner features to look out for
  2. The best eco-friendly, energy-efficient air conditioners

Air conditioners may be considered a luxury in some places, but in others they’re pretty much essential to keep you cool as the weather and the climate warm. Window air conditioners, portable air conditioners, and central air conditioning systems are more affordable than ever and, thankfully, have vastly improved in energy efficiency.

Here, we offer our top picks for the best energy-efficient air conditioners for this summer, which is likely to be just as sweltering, if not more so, than last year. We have split these into larger A/C units, suitable for bigger spaces such as open living areas or studios, and smaller units suitable for individual rooms.

If you’re not sure about which air conditioner sizes you should be considering, check out our guide: What size air conditioner do you really need?

The air conditioners below are arranged in the order of their energy usage, so it’ll help to know which size you need to pick accordingly, but any model on this list is bound to be a better choice than most of its more energy-hungry competitors of a similar size.

Best air conditioner for smaller spaces

LG-LW6019ER

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Best 14,000 Btu unit for up to 800 square feet

LG – LW1517IVSM

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Best 22,000+ Btu unit for cooling a small house

LG LW2217IVSM

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Air conditioner features to look out for

Unfortunately, many A/C units still use R410-a coolant, which has higher global warming potential than the more eco-friendly R32 coolant. However, R410-a is a very effective coolant which may have a net advantage for reduced greenhouse gas emissions by lowering energy consumption overall (R). So, if you like the look of a particular A/C and it’s energy efficient overall, the R410-a might not need to be a dealbreaker.

A quality air conditioner will have easy-to-use controls that give you a good degree of flexibility in how you use the unit. Look for things like:

  • A digital temperature display (avoid those with ‘warmer’ or ‘cooler’ settings only)
  • Built-in timer – save energy by setting the timer to start the unit just before your get home and turn it off when you’re out
  • Remote control capacity
  • Buttons that are clearly labelled and easy to use even when fumbling in the dark
  • Ability to change the direction of airflow – especially helpful if you have an oddly shaped room or need to install the unit in a strangely situated window
  • Energy-saving features like a fan that stops when the compressor is off
  • Dehumidifying mode – helpful for humid climates, especially on spring/fall days
  • Exhaust setting – so you can use your A/C for ventilation and fresh air intake without cooling
  • Variable speed compressor – more on that, here.

Finally, don’t forget noise pollution. When we think about an eco-friendly home, we sometimes forget to consider noise pollution. If an otherwise eco-friendly appliance runs loud, this in itself can make a living situation unpleasant. This is definitely something to consider if you value a quiet living space and find intermittent or loud noise disturbing while you sleep.

For more reading, see our top picks for smart thermostats.

The best eco-friendly, energy-efficient air conditioners

1

LG-LW6019ER

Leaf Score

Highlights: Our top pick for energy-efficient air conditioners – great for cooling a room up to 260-sq. ft.

Air conditioner overview

  • Btu: 6,000
  • CEER: 12.4
  • Variable Speed Compressor: No
  • Annual Energy Use: 362.9 kWh/yr
  • Category: Small

The LG-LW6019ER offers one of the highest Energy Star ratings in this category and uses 362.9 kWh/yr to provide 6,000 Btu. It is recommended by Consumer Reports with a score of 77, tends to blow air to the right of the unit, has an auto restart mode, and uses a standard 115-volt/15-amp electrical outlet. This model can cool a room up to 260-sq. ft. and can dehumidify up to 1.8 pints per hour. The 6019ER has a maximum window width of 37 inches, measures 19 9/16″ x 12 3/8″ x 19 3/8″ and weighs 56 pounds.

2

Frigidaire FFRE063WAE

Leaf Score

Highlights: Our runner-up energy-efficient AC pick, capable of cooling 200-300 square feet at a slightly lower cost than our top LG model.

Air conditioner overview

  • Btu: 6,000
  • CEER: 12.1
  • Variable Speed Compressor: No
  • Annual Energy Use: 371.9 kWh/yr
  • Category: Small

The Frigidaire FFRE063WAE is another great choice for a smaller sized A/C. Rated at 77 by Consumer Reports, this one can cool 200-300 square feet, costs a little less than the LG, and provides 6,000 Btu. This model has a remote control, electronic control with built-in timer, automatic fan speed, a dirty filter indicator, and distributes air evenly. It also has a dehumidifier function and three fan speeds and a noise level of 51 decibels. It comes with a convenient extra-long 6-foot long power cord.

The minimum window width for the Frigidaire is 24.5 inches and the maximum is 38 in. It weighs some 47 lbs. and the minimum window height needed is 13.375 in. There are a couple of extra features on this one that make it a bit more eco-friendly too, namely an eco-mode that saves energy and the inclusion of foam strips to go around the unit as you install it (which helps insulate the window and seal air gaps).

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3

LG LW8017ERSM

Leaf Score

Highlights: A solid choice in the 8,000-9,999 BTU range to consider, albeit at a slightly lower cooling capacity than our top LG pick in this category.

Air conditioner overview

  • Btu: 8,000
  • CEER: 12.0
  • Variable Speed Compressor: No
  • Annual Energy Use: 500.0 kWh/yr
  • Category: Small

In this size range, the LG LW8017ERSM is another great choice with a decent CEER (12.0) and cooling capacity (8,000 Btu). It can be controlled via the control panel, remote, smartphone app., Alexa and Google. This model weighs 58 pounds and measures 19 9/16″ x 12 3/8″ x 19 3/8″. It can dehumidify 2.2 pints per hour (52.8 in a day), and is ideal for cooling around 342 sq. ft. It uses the slightly more eco-friendly R32 coolant, has an auto-restart option and energy saver mode, and a 24-hr programmable timer.

4

LG LW1019IVSM

Leaf Score

Highlights: 9,500 BTU cooling capacity unit with a more energy-efficient variable speed compressor.

Air conditioner overview

  • Btu: 9,500
  • CEER: 13.8
  • Variable Speed Compressor: Yes
  • Annual Energy Use: 516.3 kWh/yr
  • Category: Medium

The LG LW1019IVSM has a 9,500 Btu cooling capacity and is a variable speed compressor, meaning that it is more energy efficient than comparable single speed compressor units. Unsurprisingly, this one exceeds the Federal Standard by 26.61%. The LW1019IVSM has smart connectivity and can be controlled via remote, wi-fi, smartphone app., and through Alexa and Google Assistant.

5

The Emerson Quiet Kool

Leaf Score

Highlights: Most cost-effective option in the 10,000 – 11,999 BTU range without some of the smart features of competing brands.

Air conditioner overview

  • Btu: 10,000
  • CEER: 12.0
  • Variable Speed Compressor: No
  • Annual Energy Use: 625.0 kWh/yr
  • Category: Medium

The Emerson Quiet Kool – EARC10RE1 is probably the most cost-effective option in this category. It has a 10,000 Btu cooling capacity, a CEER of 12.0 and an EER or 12.1, offers 8-way airflow louvers and a 24-hour programmable timer. It costs less than other brands, including LG, largely because it doesn’t bother with any smartphone app. controls and such.

The Emerson has a washable filter, remote control, Eco mode and a sleep mode as well as a low voltage startup to conserve energy and save money. This model also features an auto restart in case of a power failure and, as the name suggests, the Emerson Quiet Kool runs a little quieter than some other models (not in Eco mode, though, where it turns on and off). It weighs 63.9 pounds and measures 19.8 x 21.5 x 14.6 inches.

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6

LG – LW1517IVSM

Leaf Score

Highlights: A top pick in the large-sized air conditioner category thanks to its variable speed compressor and ability to cool about 800 square feet of space.

Air conditioner overview

  • Btu: 14,000
  • CEER: 14.7
  • Variable Speed Compressor: Yes
  • Annual Energy Use: 714.3 kWh/yr
  • Category: Large

The LG – LW1517IVSM with variable speed compressor/dual inverter is the top pick in this category. It is more energy efficient than other models, can cool around 800 square feet of space, runs quietly, and has remote control functionality and is smartphone compatible. If a power outage occurs, this model has an auto restart function to get things going again without you having to lift a finger.

This model also has four-way air direction, so you can tailor it to the needs of your space, and features a 24-hour programmable timer and sleep mode. It even looks pretty nice in the window and can be run on just 120 volts, unlike most other high-powered A/Cs. It weighs 112 pounds and measures 27.9 x 27.3 x 20.7 inches. The slide in-out chassis makes for easier and safer installation.

This model is priced at around $489 and uses a whopping 37.38% less energy than the U.S. Federal Standard!

7

LG LW1217ERSM

Leaf Score

Highlights: An Amazon best-seller for a reason; Consumer Reports gives it a score of 85, and the unit is capable of cooling a room up to 550 square feet.

Air conditioner overview

  • Btu: 12,000
  • CEER: 12.1 (EER, no CEER listed)
  • Variable Speed Compressor: No
  • Annual Energy Use: 750.0 kWh/yr
  • Category: Large

Even LG aren’t doing that great in terms of energy efficiency in this Btu range. One of their best options is the LG LW1217ERSM 12,000 BTU 115V Window Mounted Wi-Fi Control Air Conditioner. This is a best-seller on Amazon, has a 2017 Energy Star EER of 12.1 (the Energy Star website says 12.0 for 2015 CEER), and offers wi-fi and smartphone control. It is a top pick from Consumer Reports with a score of 85, on the basis of testing done on another LG, the LW1216ER, which is not a ‘smart’ A/C but is also rated a 12,000 Btu.

The LG LW1217ERSM can dehumidify up to 3.8 pints per hour or 91.2 per day (compared to the Soleus Air’s 52 pints), and is suitable for cooling a room up to 550 sq. ft. This model weighs in at 81 pounds, and the unit measures 22.2 in. long by 23.6 in. wide and 15 in. tall, to fit a window width of 17 in. minimum (39 in maximum), and a minimum window height of 16 in. This LG uses plastic insulation instead of Styrofoam, which is better for avoiding mold and mildew build-up. It is also quieter than other similar units if properly installed.

The LG LW1216ER costs a little less but is the model actually tested by Consumer Reports. It has all the same features of the LG LW1217ERSM minus the wi-fi and smartphone compatibility.

If your budget stretches to it, however, I’d recommend you opt for a 14,000 Btu unit from LG instead. The energy efficiency is far better, and your running costs will be lower overall. If your choice is between a 14,000 Btu model or a 12,000 Btu model, you’re probably better off with a variable speed 14,000 Btu LG than a less efficient 12,000 Btu that uses more power to do less. If you’re not convinced you need a 14,000 Btu unit, you might consider a 9,500 Btu LG instead, paired with a nice ceiling fan and some other alternatives to air conditioning.

8

LG-LW1817IVSM

Leaf Score

Highlights: A good choice if you’re looking for an 18,000 Btu model, but requires a 240 volt outlet where the 14,000 Btu model does not.

Air conditioner overview

  • Btu: 18,000
  • CEER: 14.7
  • Variable Speed Compressor: Yes
  • Annual Energy Use: 918.4 kWh/yr
  • Category: Large

The 18,000 Btu LG-LW1817IVSM with variable speed compressor also uses 37.38% less energy than the U.S. Federal Standard, is smartphone and wi-fi enabled, runs quietly, has auto restart, four-way air direction, a 24-hour programmable timer, sleep mode, and is priced at around $600. This one requires a 240 volt outlet, however, unlike the 14,000 capacity model.

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9

LG LW2217IVSM

Leaf Score

Highlights: With the ability to cool approximately 1,300 square feet, this high capacity window air conditioner scores high marks in its capacity range.

Air conditioner overview

  • Btu: 22,000
  • CEER: 14.5
  • Variable Speed Compressor: Yes
  • Annual Energy Use: 1,137.9 kWh/yr
  • Category: Large

Above 20,000 Btu, your best bet is, again, LG. However, only their LG – LW2217IVSM model gets a rating above 10.4, so pickings are slim in this range. Unless you buy the LG, you may well be better off installing central air or taking a serious look at why a 20,000 Btu seems necessary. Is your room really 1,000 square feet in size? Are there other ways to keep it cool, such as solar blinds, more thermal mass from a dark concrete or stone floor, or planting deciduous trees outside to create a shady canopy?

The LG – LW2217IVSM is a popular high capacity window air conditioner. It has a dual inverter compressor that makes it a lot less noisy than other high capacity models and also makes it a lot more energy efficient (as you can see from the table above). Typical decibel levels for this unit are 62/59/55/44 indoors for High/Mid/Low/Sleep settings respectively. Noise levels are significantly higher outside at 67/65/63/55 for the same settings.

With 4-way air direction and the capacity to cool around 1300 square feet, this is a great option for larger rooms and open plan spaces. Tech nerds will also like this unit as it boast Alexa and Google Assistant compatibility – yep, you can control the unit by voice alone. There’s also remote control functionality and smartphone compatibility, a 24-hour programmable timer, auto restart option, and energy-saver function. This model even has a filter alarm, so you know when it’s time to clean the filter to maintain efficiency.

The only real downside to this model is that it doesn’t have heating as well as cooling capacity. However, the LG weighs in at a rather low 110 pounds, while other models in this size range regularly weight in at over 200 pounds. Still, despite its slide in-out chassis design, you’re probably going to need some help installing it safely.

The LG model measures 26.2 x 25.9 x 17.7 inches and requires a 230 volt outlet. One thing to note about this model is that it uses R32 as a coolant. This type of coolant has a much lower global warming potential than most other refrigerants currently in use and has a lower risk of acute toxicity. However, it does warrant a California Prop 65 caution warning because it is made using a chemical called dichloromethane (methylene chloride). R32 itself is difluoromethane and is thought to contain no more than 0.003% dichloromethane after production (R). R410-a coolant has a higher global warming potential but may be more energy efficient overall.

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  1. I liked how you mentioned that a variable compressor in an air conditioner can help maintain the temperature you want in your home. My wife and I are wanting to prepare for the summer and we were wondering how we could keep our bedroom at a steady temperature. I’ll be sure to tell her that we should consider getting a variable compressor for the AC.

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