8 Most Energy Efficient Window Air Conditioners For Reduced Bills

Josh Mitchell

Written By

Josh Mitchell

Expert Reviewed By

Holly Curell

Last Updated On

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Keeping a home cool doesn't have to cost a fortune in power bills.

An energy-efficient window air conditioner is the key to a low-cost and environmentally friendly cool home.

However, choosing an efficient AC can be challenging.

Many things affect air conditioners' efficiency, and it can be difficult to determine what you should be looking at.

I tested, compared, and reviewed more than a dozen ACs to help you out. Let’s find the most energy-efficient window air conditioner for your home!

Quick Glance - My Recommendations

Frigidaire FFRE053WAE Window Air Conditioner,...

Frigidaire FFRE053WAE

Editor's Choice

Amana 5,000 BTU 115V Window-Mounted Air...

Amana AMAP050BW

Best Budget Option

Danby DAC060EB6WDB 6,000 BTU Window Air...

Danby DAC060EB6WDB

Best Value for Money

8 Energy-Efficient Window ACs Designed To Save Your Money

1. Frigidaire FFRE053WAE

4.2

Overall Score


Energy Efficiency

4.5

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Cooling Ability

4.0

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Value For Money

4.0

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Who Is Frigidaire FFRE053WAE Best For?

This Frigidaire window air conditioner is perfect for those looking to save as much electricity as possible while efficiently cooling small rooms.

Pros
  • Excellent energy efficiency keeps your power bill low
  • Top-notch cooling power for small spaces
  • More features than most other 5,000 BTU units
  • Low weight makes for easy installation
  • Lots of value for your money
CONS
  • Noisier than advertised
  • May collect rainwater without an awning

Frigidaire FFRE053WAE is a pretty incredible little machine.

It may not be the most powerful, but the energy efficiency and features it offers put it above most air conditioners that are direct competitors.

In terms of power consumption, there’s not much to talk about since this highly energy-efficient AC unit barely consumes it.

Its 12.1 EER matches many other units, but the Frigidaire makes about the best possible use out of every watt.

This Energy Star-certified window AC unit has the lowest annual energy use on my list at only 309.9 kWh/year.

didn’t notice any change in my electricity bills during testing, even when I wasn't using eco mode.

The Frigidaire’s performance is excellent for its 5,000 BTU cooling capacity. Its rated coverage area stands at 150 square feet (sq ft).

Still, the power was more than enough to cool a poorly insulated 170 sq ft attic space in 20 minutes.

I don't recommend overshooting the rated square footage since it quickly compromises the unit's excellent energy efficiency.

I'm just saying this Frigidaire punches above its weight.

Another factor that sets the Frigidaire apart from its competitors is its full 3-in-1 (AC, fan, dehumidifier) functionality, combined with an eco and sleep mode.

Having this much adjustability is rare in 5,000 BTU air conditioners.

You can adjust the multiple settings effortlessly with the easy-to-use front panel or the display-equipped remote control — again, a rarity in the 5K class.

Frigidaire FFRE053WAE controls

The remote even features a portable thermostat that can adjust the AC based on its location.

As a crowning cherry on this AC, the build quality exceeds its modest price tag. I ran the unit for a month straight, and it didn't as much as cough.

The only grumble I have is the noise. Frigidaire promises this is an ultra-quiet 50 dB unit, but I measured a 55 dB noise level at the lowest setting.

It’s still perfectly average with noise — just not what the box promises you. The Amana window AC unit next on my list is slightly quieter.

The installation instructions are also sub-par, but fortunately, the unit is lightweight and simple to mount anyway.

If you’re looking to keep your small room cool, you can’t do it much more energy-efficiently than with this window AC.

Feature

Details

Estimated Yearly Energy Cost

$40

EER or SEER

12.1

BTUs

5,000

Cooling Area

150 sq. ft.


2. Amana AMAP050BW

4.3

Overall Score


Energy Efficiency

4.5

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Cooling Ability

4.0

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Value For Money

4.5

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Who is Amana AMAP050BW Best For?

This Amana window AC unit is a great option for homeowners with small rooms looking for an affordable unit to buy and operate.

Pros
  • Affordable price tag
  • Great energy efficiency even without an Energy Star rating
  • Reasonably quiet unit
  • Simple manual controls
  • Good cooling chops for small rooms
CONS
  • Cheap build quality
  • Lack of remote

If you’re looking for an energy-efficient window unit air conditioner, the unit’s budget-friendliness probably matters to you.

Amana AMAP050BW will please your wallet with both its low price and great energy savings.

On paper, this window AC unit loses to its Frigidaire 5K BTU competitor.

It has a slightly lower 11 EER rating, and it's not Energy Star-rated — but that's not the whole story.

The Amana’s annual energy costs are only marginally higher than Frigidaire’s, despite it drawing a bit more power.

The bottom line is that you will barely notice this window air conditioner on your electricity bill.
Amana AMAP050BW controls

One factor contributing to the energy savings is the Amana’s manual controls.

It has two simple control knobs on the front panel: one for choosing between high and low AC or fan and another for picking one of the seven temperature settings.

Sure, you’ll have to walk to the unit to adjust it. At the same time, though, it doesn’t waste power on LCD displays and remote control connections.

The simple controls don’t mean this window unit lacks in capability.

Its 5,000 BTU cooling capacity is enough for a 150 sq ft coverage area, but it can deal with a bit more than that.

I wouldn't use this unit anywhere above its coverage area, but that's not what it's designed for anyway.

In an appropriately sized room, I enjoyed pleasant and cool indoor temperatures within 30 minutes, even with blazing 100 degrees outside.

The Amana edges ahead of the Frigidaire in the noise department.

Whereas its competitor promises 50 dB noise levels at the low setting, this one actually delivers. It's a reasonably quiet window air conditioner.

This unit also offers eight-way airflow control.

Being able to freely adjust the air direction can make a big positive difference if you can’t place the unit in an ideally located window space.

The build quality is admittedly pretty cheap, and the loose panels may rattle as the unit runs.

There's an easy fix, though — stick some foam between the panels or tape them to the frame.

This Amana window AC is a basic device in the best possible way.

There's nothing fancy or superfluous about it — it provides affordable cooling, and that's enough.

Feature

Details

Estimated Yearly Energy Cost

$41

EER or SEER

11

BTUs

5,000

Cooling Area

150 sq. ft.


3. Danby DAC060EB6WDB

Energy Efficient Window AC With Value For Money

4.2

Overall Score


Energy Efficiency

4.0

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Cooling Ability

4.0

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Value For Money

4.75

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Who Is Danby DAC060EB6WDB Best For?

This Danby window AC unit is a low-cost and value-packed solution for medium and small rooms.

Pros
  • Low purchase and ownership costs
  • Nice, strong cooling in up to medium-sized spaces
  • Compact and reasonable lightweight design for its BTUs
  • Fully-featured simple controls and portable thermostat
CONS
  • Appearance may divide opinions
  • Short remote range

Who doesn't love getting a lot of bang for your back?

Danby DAC060EB6WDB delivers a 1-2-3 value combo with an affordable cost, high energy efficiency, and excellent cooling capacity for small and medium-sized spaces.

The Danby provides the same kind of efficiency as the list-topping Frigidaire, offering an excellent 12.1 EER rating and an Energy Star label.

Danby DAC060EB6WDB controls

Although the estimated annual energy use and costs are marginally higher than on the Frigidaire, you'll still barely notice this air conditioner on your power bill.

Besides, there's a good reason this machine eats one bite more electricity.

Danby ups the cooling capacity compared to the previous duo, bringing it to 6,000 BTU.

That gives this window unit a coverage area of 250 sq ft — enough for a medium-sized living room, for example.

he unit uses the electricity it consumes efficiently to produce a strong flow of cold air.

With 100°F temperatures outside, I cooled a room at the upper end of the rated coverage area down to 71°F in around 30 minutes.

As an interesting fact, the Danby was even able to push the temp below its 64°F stated minimum capacity.

I should note that pushing the machine that far isn't good for its longevity, but it does demonstrate Danby's cooling chops.

In functionality, this air conditioner is comparable to the Frigidaire.

It has the same three primary use modes (AC, fan, dehumidifier), alongside a timer and eco and sleep mode options.

The electronic controls are also similar, and the unit is straightforward to use.

You even get a similar portable thermostat on the display-equipped remote control for automatically adjusting the AC.

The range of the remote thermostat is shorter than Frigidaire's, but it still works nicely.

And the best part is that you get all of this at a surprisingly low initial cost.

Really, the only thing I can complain about with the Danby is the… "unique" front grille appearance.

Still, beauty is in the eye of the beholder, and you may find the large-eyed mesh appealing.

Overall, the two words to summarize this Danby AC are “great value.”

Feature

Details

Estimated Yearly Energy Cost

$48

EER or SEER

12.1

BTUs

6,000

Cooling Area

250 sq. ft.


4. Friedrich Chill Premier CCW06B10B

4.2

Overall Score


Energy Efficiency

4.5

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Cooling Ability

4.0

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Value For Money

4.0

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Who Is Friedrich Chill Premier CCW06B10B Best For?

This is a great window AC unit from Friedrich to place in a medium room if you want flexible control in your smart home.

Pros
  • Outstanding cooling output for small to medium-sized areas
  • Wi-Fi capabilities
  • Highly accurate thermostat
CONS
  • Poor construction quality
  • Temperamental Wi-Fi

Friedrich is one of the most popular window air conditioner brands for a reason.

The company’s Chill Premier CCW06B10B is an energy-efficient window AC unit for medium rooms that comes packed with smart home features.

In many ways, the Friedrich resembles its Danby competitor.

This Energy Star-certified machine bears a 12.1 EER rating (energy efficiency rating), so you can rely on it bringing home nice energy savings.

The estimated annual energy use is identical to Danby at around 371 kWh/year.

Still, the unit does draw a few watts more power, which results in marginally higher annual estimated energy costs.

So, where does that extra electricity go?

It feeds the built-in Wi-Fi module.

Friedrich Chill Premier CCW06B10B controls

The Chill Premier supports full smartphone connectivity, allowing you to control its 3-in-1 functionality (including eco and sleep mode) from anywhere. 

You can even hook it up to an Amazon Alexa or Google Assistant.

The Wi-Fi can be temperamental unless your network is set to a 2.4 Ghz frequency.

Most modern routers default to 5 Ghz, so if you keep losing connection, I recommend checking your router settings.

If you'd prefer to use traditional controls, you can do everything the Wi-Fi does through the front panel or the included remote.

The remote is picky about the range and use angles, though, since it's an infrared unit.

In terms of cooling capacity, the Friedrich sports 6,000 BTUs of power, which is enough for up to 250-square-foot rooms.

The unit’s thermostat is highly accurate, allowing it to use every available BTU optimally and avoid racking up your power bills unnecessarily.

Sadly, Friedrich's overall build quality has dipped in recent years. The Chill Premier feels flimsy, and its body panels may rattle as the compressor runs.

That's nothing some foam or a bit of duct tape won't fix, though.

The build quality is a particular bummer, considering this unit's generally high cost.

That said, keep an eye out on Amazon — the Chill Premier is often on sale for a much more reasonable price.

In the end, Friedrich Chill Premier is still an excellent choice for cooling medium rooms, particularly if you want the convenience of Wi-Fi controls.

Feature

Details

Estimated Yearly Energy Cost

$50

EER or SEER

12.1

BTUs

6,000

Cooling Area

250 sq. ft.


5. Midea U MAW10V1QWT

4.3

Overall Score


Energy Efficiency

4.5

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Cooling Ability

4.0

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Value For Money

4.4

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Who Is Midea U MAW10V1QWT For?

his Midea high-tech, energy-efficient window AC is a prime choice if you want strong cooling for huge rooms paired with the latest compressor and connectivity solutions.

Pros
  • First-class cooling power for even huge rooms
  • Inverter compressor provides high energy efficiency and low noise
  • Excellent Wi-Fi connectivity
  • U-design looks good and doesn’t block the window
CONS
  • Expensive
  • Involved installation with poor instructions

Midea is well-known for its affordable basic window air conditioners for small spaces.

The Midea U, however, shows that the brand can build a premium AC as well.

This unit has the most cooling power out of any machine on my list.

It packs a whopping 10,000 BTU of cooling capacity, translating to a 450 sq ft coverage area.

The cool air blows out strongly, and you can actually feel the airflow the advertised 20 feet away.

I had no trouble bringing a room about 100 square feet above the rated coverage area down to comfortable temps with triple-digit weather outside.

All that power should mean the Midea U guzzles electricity, but it has an ace up its sleeve.

Unlike other units on my list, this Energy Star-certified window air conditioner uses an inverter compressor, which results in a shocking 15 EER rating.

The estimated annual energy usage sits at 500 kWh/year, and the cost at $52 — barely higher than Friedrich's, which has 4,000 BTUs less power.

This unit does draw up to 10 amps of current, though, so keep that in mind when plugging it in.

Another benefit of the inverter compressor is the unit’s very quiet operation.

Midea U MAW10V1QWT controls

I measured the running noise at about 48 dB on average, which beats most other units I’ve listed.

Like Friedrich, the Midea U can connect to a smartphone or voice assistant through Wi-Fi.

The connection is more stable than the former unit's, and the mobile app can track the AC's energy consumption.

As its name implies, this unit has a U-shaped saddle design, with the window pane sliding between the indoor console and the compressor.

The window provides further sound insulation while the unit still allows you to see outside.

The unique shape, however, makes this AC more challenging to install.

It's relatively straightforward once everything clicks in place, but the substandard instructions, combined with the unit's weight, make the job more challenging.

The Midea U is worth the effort, though. When comparing energy usage to cooling power, this unit is pretty much unbeatable.

Feature

Details

Estimated Yearly Energy Cost

$52

EER or SEER

15

BTUs

10,000

Cooling Area

450 sq. ft.


6. Haier Serenity ESAQ406TZ

4.2

Overall Score


Energy Efficiency

4.5

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Cooling Ability

4.0

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Value For Money

4.0

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Who Is Haier Serenity ESAQ406TZ Best For?

This Haier Serenity AC is a quiet and efficient option for homeowners who don’t want to spend hours sweating and puzzling over a convoluted installation process.

Pros
  • Simple to install with a good mounting kit
  • Top-notch packaging
  • Good, even cooling performance in medium rooms
  • Water plug allows draining when necessary
CONS
  • A bit pricier than it needs to be
  • Heavy

With your home turning into a sauna, a lengthy AC installation process is the last thing you want.

Haier Serenity Series ESAQ406TZ makes getting your energy-efficient window air conditioner hooked up as simple as it will get.

This Haier unit stands on the same line as the FriedrichDanby, and Frigidaire, offering a 12.1 EER rating and Energy Star certification.

As such, you can rely on it being an energy-efficient choice.

The 490-watt energy draw is identical to Frigidaire and Danby.

However, the annual estimated energy use is roughly 397 kWh/year, resulting in an approximate yearly energy cost of $52.

The Haier makes good use of that power by bumping its cooling capacity to 6,200 BTU.

Although on paper that corresponds to 250 sq ft of cooling area, the Haier packs a bit heavier punch than the other 6K units.

What makes this window air conditioner so easy to install is the EZ Mount window kit supplied in the box.

This is one of the better mounting kits I've seen for window AC units and features nice quality parts for hooking the machine up to your window sill.

Another factor contributing to easy mounting is the excellent packaging.

It’s sturdy enough to protect the unit even from the clumsiest UPS driver while allowing you to easily pull the unit out.

I had this thing set up in about 10 minutes — something of a record.

Once I had it running, this AC surprised me with how little noise it made.

Haier Serenity ESAQ406TZ

It's on the same level as the Midea, making it a great option for a medium or small bedroom.

The louvers on the unit point upward, which is a good thing as it helps distribute cool air more evenly.

It does slow down the cooling effect, though, so take it into account in your energy use calculations.

On the back of the unit is a water plug, which allows you to empty condensation from the unit.

It can be useful in humid regions, but draining the AC does reduce its energy efficiency.

The Haier is a bit heavy, too, but fortunately, the good install kit means it doesn’t matter much.

Feature

Details

Estimated Yearly Energy Cost

$52

EER or SEER

12.1

BTUs

6,200

Cooling Area

250 sq. ft.


7. GE Profile PHC06LY

Quietest Energy-Efficient Window AC

4.1

Overall Score


Energy Efficiency

4.3

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Cooling Ability

4.0

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Value For Money

4.0

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Who Is GE Profile PHC06LY Best For?

This GE Profile unit is the best window air conditioner for those who want to enjoy the quietest cooling experience you can find.

Pros
  • About as quiet as a non-inverter AC can be
  • Strong and even cooling in medium-sized spaces
  • Wi-Fi connectivity
  • Good mounting kit
  • Sleek modern aesthetics
CONS
  • Needs more space inside than most models
  • High power draw for the BTUs

The GE Profile PHC06LY has a lot of similarities with the Haier unit, which isn't surprising considering Haier owns GE these days.

That said, the GE edges ahead in one regard — noise.

Or perhaps I should say lack of noise. This is an incredibly quiet window AC unit!

The advertising materials promise a 40 dB noise level, and the unit actually achieves it on the lowest setting.
GE Profile PHC06LY

On medium, I measured 45 dB of noise three feet away, which is even better than the inverter-equipped Midea.

While it’s not quite as energy-efficient as most models on my list, the GE’s 11.5 EER score (energy efficiency rating) is higher than the Amana unit's.

At around 520 watts, the power draw is high, but the GE makes good use of the electricity.

Case in point, its estimated annual energy cost is $52, identical to its Haier relative.

The GE also matches the Haier in cooling capacity, providing 6,200 BTU, which is enough for 250 sq ft.

This unit’s cool airflow was strong enough to get my ceiling fan turning on the highest setting.

With the upward-slanted vents (again, same as Haier), the cooling power is outstanding in an appropriately sized room.

Installing this window air conditioner is straightforward since it comes with the same EZ Mount kit as the Haier (they really are relatives).

The GE weighs a bit more, though, so you have to put a bit more muscle into the process.

Another family feature is the drain plug on the back of the unit. As I said, draining the unit may occasionally be necessary in high-humidity climates.

Still, you need some cooling water in the drain pan to maximize energy-efficient operation.

This GE AC sports Wi-Fi capabilities, giving it smart home features comparable to the Friedrich and Media U machines.

You should keep the remote control at hand, though, because GE has made an incomprehensible decision of allowing you to activate the sleep mode only through the remote.

Finally, I want to note that the GE is one of the best-looking ACs on my list. The aesthetics are welcome because it pokes inside more than most.

Feature

Details

Estimated Yearly Energy Cost

$52

EER or SEER

11.5

BTUs

6,200

Cooling Area

250 sq. ft.


8. LG LW8016ER

4.2

Overall Score


Energy Efficiency

4.5

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Cooling Ability

4.0

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Value For Money

4.0

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Who Is LG LW8016ER Best For?

This LG window air conditioner is tailor-made for homeowners who want to cool down bigger rooms while keeping their electricity bills reasonable.

Pros
  • Plenty of cooling capacity for medium to large spaces
  • Reasonable price brings a lot of value
  • Strong dehumidifier mode and drain plug
  • Good energy efficiency for its BTUs
CONS
  • Loud-ish running noise
  • Heavy unit needs an outdoor support bracket

The last entry on my buying guide is certainly not the least.

LG LW8016ER dishes out more cooling power than most while still keeping things reasonably energy-efficient.

This LG window AC unit has a similar ratings to most other models on my list.

It bears a 12 EER rating and Energy Star certification, so there’s no doubt of its energy efficiency.

Now, the $65 estimated annual energy cost is admittedly the highest on my list.

However, you have to take into account that with its 8,000 BTU cooling power, it packs the second-biggest cooling punch right after the Midea U.

For a non-inverter window air AC, the LG is very energy-conservative.

With an estimated annual energy use of 500 kWh/y (same as the Midea), it consumes about half the electricity as comparable units without an Energy Star rating.

Those 8,000 BTUs of power are rated for spaces up to 300 sq ft in size.

That said, I was able to cool even a 500 sq ft room without problems during testing (remember, overshooting the coverage area ruins energy efficiency).

The LG serves up the usual 3-in-1 functionality.

I have to give a special shoutout to the effective dehumidifier mode, which, at 2.2 pints/hour, was the best I reviewed.

This unit will be great in high-humidity regions, particularly because it has a drain plug.

The display-less remote that comes with the unit is very basic, but it has a long range and good use angles.

The buttons are responsive, big, and distinctly shaped, making the remote easy to use even in the dark. With that said, it’s a pity this unit has no sleep mode.

You may not want this unit in your bedroom, though, because it is pretty loud.

Some of that noise (at least in my case) was due to the front filter panel, which was loosely attached and rattled during operation.

A piece of foam stuck between the panel and the unit cured that issue.

A little bit of rattling is a decent trade-off for this unit's low price point, though.

If you're looking for a value-packed, energy-efficient window air conditioner for medium to large living rooms, stop looking — you've found it.

Feature

Details

Estimated Yearly Energy Cost

$65

EER or SEER

12

BTUs

8,000

Cooling Area

300 sq. ft.


Energy Star Air Conditioners Compared

Preview

Name

Rating

Yearly Energy Cost

EER or SEER

BTUs

Price

Frigidaire FFRE053WAE Window Air Conditioner,...

Frigidaire FFRE053WAE

4.2

$40

12.1

5,000

Amana 5,000 BTU 115V Window-Mounted Air...

Amana AMAP050BW

4.3

$41

11

5,000

Danby DAC060EB6WDB 6,000 BTU Window Air...

Danby DAC060EB6WDB

4.0

$48

12.1

6,000

Friedrich Chill Premier 6000 BTU Smart Wi-Fi...

Friedrich Chill Premier CCW06B10B

4.2

$50

12.1

6,000

Midea 10,000 BTU U-Shaped Smart Inverter...

Midea U MAW10V1QWT

4.3

$52

15

10,000

Haier 6,200 BTU Ultra Quiet Window Air...

Haier Serenity ESAQ406TZ

4.2

$52

12.1

6,200

GE Profile Ultra Quiet Window Air Conditioner...

GE Profile PHC06LY

4.1

$52

11.5

6,200

LG 8,000 BTU Window Air Conditioner, 115V,...

LG LW8016ER

4.2

$65

12

8,000


How To Buy An Energy-Efficient Window Air Conditioner

If you want the maximum energy savings from any window air conditioner, you shouldn't rush to buy the first unit that touts itself as "energy-efficient."

Many things impact how energy-efficient air conditioners are, and using the wrong device in the wrong place can turn it into an energy hog.

Here's my breakdown of the most crucial things to remember when shopping for energy-efficient window air conditioners.

EER Rating Makes All The Difference

I recommend looking for window air conditioners with an EER rating of 10 or higher to ensure energy-efficient performance.

Energy Guide of $40 with 12.1 EER
The energy efficiency of all air conditioners is measured using the energy efficiency ratio (EER).

The EER calculation can get a bit complex, but the basic gist is simple — the higher the EER score, the more energy efficient the unit is.[1]

There are a couple of variant calculations, like seasonal and combined energy efficiency ratio, but I’ll talk more about that later.

In general, though, look for units with at least a 10 EER score (all units on my list satisfy this requirement).

If you want guarantees about a unit’s performance, I recommend also looking for Energy Star-certified ACs.

10 EER Rating

TL;DR: EER rating is of paramount importance if you wish to buy an energy efficient AC. The higher the EER rating, the more energy efficient it is.

More Powerful Isn’t Always Better (BTU Rating)

For better energy performance, choose window units with a lower BTU rating over higher BTU ACs.

I advise choosing a window air conditioner with the lowest possible BTU rating.

BTU stands for British thermal unit, the standard measurement for evaluating window AC units' cooling power.

More powerful units generally consume more electricity (although there are exceptions like the Midea U), which means less powerful units are typically more energy efficient.

TL;DR: To improve energy efficiency and lower the running cost, you must choose the right BTU AC for the covered area. Window ACs with higher BTU than needed will be less energy efficient.

Match Your AC To Your Room Size

Match your air conditioner’s BTU rating as closely as possible to the room’s square footage to keep it operating at maximum efficiency.

An AC unit’s BTU rating corresponds directly to a certain square footage. As with EER, a higher BTU rating means the AC can cover larger square footage.[2]

To cool a larger room, you need more BTUs, which means running the AC will cost more.

However, both under- and oversized window units are incapable of operating at maximum efficiency, which will cost you extra.

This is why you should always match the BTU as closely as possible to the room's square footage.

Energy Star Savings Table Air Conditioners

Source: ENERGY STAR

TL;DR: You must measure the covered area that requires cooling before choosing the BTU capacity of your window AC.

Consider A Rotary Vs Inverter Compressor

Window air conditioners equipped with inverter compressors are more energy-efficient, but they also tend to cost more.

Modern inverter compressors spin continuously instead of powering on and off as standard rotary compressors, which makes them more energy-efficient.

It may seem illogical, but the spin-up and slow-down sequences are very power-consuming, so inverter compressors end up saving energy in the long run.

However, inverter window AC units tend to cost more, so consider your purchasing priorities.

TL;DR: Window ACs with inverter compressors are more energy efficient but they have a higher upfront cost.

Choose A Window AC Unit With Multiple Fan Speeds

I recommend buying a window air conditioner with adjustable fan speeds so you can control its power and save energy.

If it's already fairly cool in your home, running your AC at full blast is a waste of energy.

All units on my list have at least two fan speed settings, so you can tone them down once your home has reached the desired temperature.

Most window AC units with electronic controls have an Auto fan mode that adjusts the fan speed automatically, meaning you won't have to worry about it.

TL;DR: Window ACs with adjustable fan speeds can allow you to lower it to save up on energy cost. 

Go For A Low-Noise Air Conditioner (DBA)

Try to find an AC that makes less than 50 dB of noise to keep it from bothering you with its loud roar.

Silent window air conditioners don't exist, but some are quieter, and some are slightly louder than others.

Low noise levels won't save energy, but they will save your nerves.

In general, I would look for units that make 50 dB or less noise during regular operation.

This sound level is lower than an average conversation, and most people won't find it too bothersome.[3]

quiet window ac

TL;DR: Window ACs are louder than mini splits. If you are annoyed by noise, make sure you get one with dB range lower than 50.

Improve AC Performance With Tight Installation

Look for lightweight window air conditioners with good mounting kits to ensure the AC covers the entire window opening.

Light window AC units with complete window kits, like the Haier Serenity, are easier to mount to the window.

With simple mounting, you can then focus on ensuring the AC is secured as tightly as possible to the window.

This eliminates gaps that could lead to air leakage and reduced air conditioner efficiency.

TL;DR: Make sure the installation kit is tight and that there are no gaps in between to improve insulation.

Keep Your AC Energy-Efficient With Simple Maintenance

I advise looking for window air conditioners with a front-loading washable air filter and a pull-out chassis to make maintaining them easier.

Keeping your window AC unit clean and well-maintained keeps it energy-efficient for a longer time.

A front-loading washable air filter is easy to pull out and saves you further money on replacements.

A pull-out chassis allows you to remove the air conditioner from its shell and gently clean dust and dirt from the internal components.

TL;DR: Windows ACs need to be maintained regularly to ensure they operate at max efficiency. Hence, make sure they are easy to maintain.

Extra Features To Consider

In addition to the above key features, there are smaller considerations that are still important. They may not directly affect how energy-efficient your unit is.

However, they can still make for a better user experience.

  • Warranty:
    Air conditioners can be surprisingly delicate machines. A good warranty protects your investment from manufacturing flaws and clumsy delivery personnel.
  • Remote:
    A good remote lets you adjust your AC from your bed or couch. This way, you can adjust the settings to improve the unit's performance even when you're feeling too lazy to get up.
  • Wi-Fi Connectivity:
    A Wi-Fi module enables smart home features, like smartphone and voice module operation. You can control WiFi-enabled ACs from anywhere, which can help you optimize their performance over the day.

TL;DR: Window ACs can feature several additional functions. While they may add to the overall cost, some functions, such as WiFi connectivity, can improve quality of life.

How We Review & Rank Our Product List

At Air Conditioner Lab, our team follows a similar process when evaluating all products reviews before formulating our final lists for readers.

We begin by gathering data sources directly from brands, e-commerce platforms, online retailers and press releases.

These are then added to a master file we use to compare features specifications from all Air Conditioner models. You can access this Air Conditioner Sheet Here.

Next, we narrow down all the products on the market by evaluating user reviews, ratings and feedback from a wide variety of online and in-person sources.

Our team then discusses and co-ordinates our first hand experiences using these products, as well as gather independent opinions and feedback through Youtube and customer reviews.


Understand EER And SEER In AC Units

The difference between the EER and SEER ratings is that the EER score measures an AC unit's performance at 95°F. At the same time, SEER takes into account the entire season.

SEER Label

The EER and SEER both measure air conditioners’ energy performance, but there is one significant difference between them — the “S.”

EER is a standardized efficiency measurement that’s always calculated for an outdoor temperature of 95°F to put all ACs on the same line.

Yet, there’s no place on Earth where it’s 95°F year-round.

SEER (or seasonal energy efficiency ratio) calculates the efficiency at a temperature range from 64°F to 104°F.

This measurement gives you a more accurate idea of the unit’s efficiency, but it may not be available for all air conditioners.

These are two different measurements, so you can't compare one unit's EER score to another unit's SEER score.

Remember to always match the ratings when comparing units.

Also, looking at the EER rating gives you a better idea of an AC's efficiency in hot climates, while the SEER may be more accurate in varying or milder climates.

TL;DR: Both SEER and EER ratings are important metrics for measuring the Window AC's efficiency. EER rating relates to how it performance at 95°F year-round; whereas, SEER rating relates to how it performs in changing temperature over the year.


FAQ

Does Outside Temperature Affect Wndow AC Efficiency?

Yes, outdoor temperature can have a significant effect on AC efficiency. The hotter it is outside, the harder your air conditioner has to work, which will consume more power.

Are Inverter Window Air Conditioners More Efficient?

Inverter ACs can be more efficient since they avoid the power-heavy spin-up sequence of rotary ACs. However, these ACs often cost more up-front.

How Can I Reduce My Window AC’s Power Consumption?

You can reduce your AC’s power consumption by, for example, keeping it clean and well-maintained, lowering fan speeds once your room has cooled down, ensuring proper room insulation, and by using programmable timers or thermostats.

Is It Cheaper to Run a Window AC All the Time?

It can be cheaper to run an AC continuously as maintaining temperatures is easier on the machine than cooling a hot room.

However, you should use an auto mode if possible to ensure the AC lowers its fan speeds when the room is cooled down.

How Much Electricity Does a Window AC Use Per Hour?

A window AC may consume anywhere from around 400W to 1,750W of power — or even more. The electricity consumption depends entirely on the unit’s power and efficiency.

What’s The Best Energy-Efficient Window Air Conditioner For You?

Plenty of factors can affect how energy-efficient any given air conditioner is.

With my buying guide, you’re now fully armed to compare different units and find the most efficient AC for your home.

Just for a reference point, though, my top recommendation out of the units on my list is Frigidaire FFRE053WAE

It may not work for the biggest rooms, but within its rated square footage, its efficiency is simply unmatched.

My #1 Recommendation
Frigidaire FFRE053WAE

  • Excellent energy efficiency keeps your power bill low
  • Top-notch cooling power for small spaces
  • More features than most other 5,000 BTU units
  • Low weight makes for easy installation
  • Lots of value for your money

References: 

  1. https://www.energy.gov/energysaver/room-air-conditioners
  2. https://www.calculator.net/btu-calculator.html
  3. https://hearinghealthfoundation.org/decibel-levels
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Josh Mitchell

Founder

Josh Mitchell
My name is Josh and I am obsessed with home appliances. From portable AC units to heaters and air purifiers, I enjoy testing, learning and using these devices to improve the air quality inside my family home.

My Favorite Home Appliance?

Midea U Shaped Window Air Conditioner

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