6 Best 12,000 BTU Air Conditioners For 400-600 Sq Ft

12,000 BTU air conditioner equals exactly 1 ton. They are used as mid-sized AC units that can cool down larger rooms, or even whole flats.

How many square feet will a 12000 BTU air conditioner cool?

In short, the 12k units can cool down rooms from 400 sq ft (low-end) to 600 sq ft (high-end). That includes:

• 20×20 rooms.
• 22×22 rooms.
• 24×24 rooms.
• 25×25 rooms.
• 2 smaller 16×16 rooms.
• Small flats up with up to 600 sq ft total square footage.

With 12,000 BTU units, you have more AC types available than for a smaller 8,000 BTU or 10,000 BTU units. That’s because, in addition to 12,000 BTU portable and window air conditioners, you have the excellent option to choose the outrageously energy-efficient (translation: electricity saving) ductless 12,000 mini-split AC units.

These high-efficiency units can use less than 1000W of power input to produce 12.000 BTU output (12+ EER rating).

The most efficient 12,000 BTU mini-split – the MRCOOL – DIY-12-HP-115B25 – has an estimated yearly operating cost of $72 and a 20-year lifespan. Comparatively, standard 12,000 BTU window or portable units can have $140+ yearly electricity costs and have a 10-15 year lifespan.

Given the most important specs – energy efficiency, room coverage, max. airflow, noise levels, and so on – we have gathered a list of the best 12,000 BTU mini-split, window, and portable units.

To familiarize ourselves with the specific metrics, we will go through all the key factors when deciding which 12,000 BTU AC unit is best for your situation. If you want to skip directly to the list, comparison, and individual 12,000 BTU AC unit reviews, you can do that here:

Skip To List Of Best 12,000 BTU AC Units In 2023

Let’s start with clearing up the most frequently asked question about 12,000 BTU air conditioners:

What Is The 12,000 BTU AC Unit Room Coverage?

As we’ve seen, the 12,000 BTU air conditioners can cool rooms from 400 sq ft to 600 sq ft. It’s important to understand how you can properly size an air conditioner.

The most basic rule of thumb for 12,000 BTU AC sizing is the EPA’s energy-saving recommendation for how many BTUs are needed to cool 1 sq ft area:

“To cool down 1 sq ft, we need 20 BTUs.”

If we use this rule and apply it to 12,000 BTU air conditioners we get:

Total Coverage = 12,000 BTU / 20 BTU per sq ft = 600 sq ft

We need to take into account that this is a rough estimate and quite a conservative BTU rule for cooling. In the heatwave, 20 BTU per sq ft might not be enough. To make sure our 12,000 BTU air conditioner will be powerful enough to cool down a room of certain square footage, we should take 25 BTU per sq ft or even 30 BTU per sq ft.

Let’s calculate the room coverage of 12,000 BTU for:

• 20 BTU per sq ft = 600 sq ft. Conservatively, 12,000 BTU air conditioners can cool down up to 600 sq ft spaces.
• 25 BTU per sq ft = 480 sq ft. The most realistic estimate is that 12,000 BTU AC units can properly condition the air in areas up to 500 sq ft.
• 30 BTU per sq ft = 400 sq ft. Better-safe-than-sorry estimate is that a 12k air conditioner can adequately lower the temperature in rooms up to 400 sq ft.

If you have sub-average insulation and live in hot Texas, 400 sq ft coverage is a more appropriate figure to use for 12,000 BTU units.

If you live up north and have good insulation with little direct sun exposure, you can cool down spaces up to 600 sq ft with any 12,000 BTU air conditioner.

Which Is The Best Type Of 12,000 BTU Air Conditioner?

When looking to find an AC capable of delivering 12,000 BTU cooling output, you can choose between 3 types:

1. 12,000 BTU ductless mini-split AC units.
2. 12,000 BTU portable air conditioners.
3. 12,000 BTU window air conditioners.

It’s hard to say that one type is better than others; all 3 have pros and cons.

For example, mini-splits have superb energy-efficiency, heating options, quietest operation, and last for 20 years, but they are also more expensive, immovable (like window AC units), and may require professional installation.

Portable 12k units are very easy to install and use (just plug it in 115V outlet), they have a quiet operation and can be moved around with ease. Obviously, they use electricity less-efficiently than mini-splits or window ACs and have a 10-year lifespan.

Window AC units capable of producing 12,000 BTU are cheap and quite energy-efficient, but they steer your window, limit the natural light, and can’t be moved easily.

That’s why you will find 6 AC units with 12,000 BTU in the list below: 2 are mini-splits (ultimate best MrCOOL 12k DIY and a cheaper Senville version), 2 are portable (energy-efficient Whynter unit and one made by Frigidaire), and 2 are window (the superb Midea U Inverter and an energy-efficient TOSOT unit.

Let’s look at the single most important specification when buying 12,000 BTU air conditioners:

How Much Electricity Do 12,000 BTU Air Conditioners Use?

12,000 BTU units run on anywhere from 1000W to 2000W when at max. power use. Of course, the preference is always to be as close to 1000W as possible; those are the Energy Star rated energy-efficient AC units.

The electricity bill here is quite easy:

• 1000W 12,000 BTU AC units use 1 kWh per hour. That’s 1000 kWh per 1000 hours (roughly 1 season).
• 2000W 12,000 BTU AC units use 2 kWh per hour. That’s 2000 kWh per 1000 hours.

If we multiply these numbers with the average kilowatt-hour price of $0.1319, we get:

• Highly energy-efficient 1000W units use about $131.19 of electricity per cooling season.
• Less energy-efficient 2000W units use about $262.38 of electricity per cooling season.

That’s a $131.19 difference in a year and a $1000+ difference in 10 years.

This is exactly why energy-efficiency is the single most important metric when picking the 12,000 BTU air conditioners (or any other capacity AC unit).

For more information about how much does running a 12,000 BTU air conditioner costs, you can check out the AC running cost calculator here. Here is a quick calculation:

How to determine which 12,000 BTU are actually energy-efficient?

In the comparison table below, you will find 3 different HVAC metrics that determine the energy-efficiency of 12,000 BTU AC units: SEER, EER, and CEER rating.

EER is the most basic unit; you get it by dividing 12,000 BTU with max. wattage input. CEER is a “Combined EER” that also includes power usage during the sleep mode. The most relevant of them all is SEER; “Seasonal EER” measures how energy-efficient an AC is throughout the season, including all the fan speed settings.

Example: The best 12,000 BTU mini-split – MRCOOL – DIY-12-HP-115B25 – has the absolute best energy-efficiency with a massive 22 SEER rating. If you calculate the EER rating, you get a 12.5 because the MRCOOL mini-split uses less than 1000W to produce the 12,000 BTU output. But what is more important is how well the overall energy-efficiency (throughout the cooling season) holds; that’s that beautiful 22 SEER rating.

Important note: Given the 3 different ratings, it’s difficult to directly compare the 12,000 BTU units head-to-head as far as energy-efficiency is concerned. Here is a little help to get a handle on which 12,000 BTU AC types use how much energy:

• Mini-splits are extremely energy-efficient (below $160/cooling season).
• Portable AC units have decent energy-efficiency (below $260/cooling season).
• Window AC units have a good energy efficiency (below $240/cooling season).

Be aware that these are rough estimates, based on average energy consumption, the average price per kWh, and the 1,000 h cooling season.

Nonetheless, the key takeaway is this:

Even though 12,000 BTU mini-splits cost $1000 more than window or portable units, they are the smarter long-term investment. You save much more than $1000 in electricity bills alone in 10 or 15 years; and mini-splits last 5-10 years longer.

What Is The Quietest 12,000 BTU Air Conditioner?

Quiet operation is a requirement for all 12,000 BTU air conditioners. Nonetheless, some are quieter than others.

If you check the list of the quietest window air conditioner and quietest portable AC units, you can see that anything below 55 dB is considered very quiet. Only a few years ago, you would hardly find a window or portable AC unit with below 60 dB.

With the invention of quiet inverter compressors and airflow optimizers, a drop in decibels could be achieved.

That being said:

No window or portable AC unit can even be as quiet as 12,000 BTU mini-split air conditioners. While 55 dB is considered super silent for other types of AC units, the mini-splits have caused a revolution as far as noise levels are concerned.

With below 40 dB noise levels (that’s not a typo), the 12,000 BTU mini-split conditions are considered the quietest air conditioners by far.

This is because of the split-system design. The noisiest part of the AC – the compressor – is located in the outdoor unit. The indoor unit can therefore be super silent; the only source of noise is the fan. The fan makes less than 40 dB of noise levels.

Here’s the outtake:

Mini-splits are by far the most silent type of air conditioners. That’s not only true for 12,000 BTU units but for all mini-split AC units.

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With all this in mind, let’s have a look at the top-rated 12,000 BTU mini-split, portable, and window air conditioners:

Top 12,000 BTU Air Conditioners (List + Comparison)

1. MRCOOL – DIY-12-HP-115B25: The Ultimate Best Energy-Efficient 12,000 BTU Mini-Split AC Unit.
2. Whynter Elite ARC-122DS: Best 12,000 BTU Portable Air Conditioner.
3. Midea U Inverter 12k: Best 12,000 BTU Window Air Conditioner.
4. Senville SENL-12CD: Cheap 12,000 BTU Ductless Mini-Split AC Unit.
5. Frigidaire FFPH1222U1: Best 12,000 BTU Portable AC Unit With Heater.
6. TOSOT 12,000 BTU: Energy-Efficient 12k BTU Window Air Conditioner.

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1. MRCOOL – DIY-12-HP-115B25: The Ultimate Best Energy-Efficient 12,000 BTU Mini-Split AC Unit

MrCool 12k is the pinnacle of 12,000 BTU air conditioners. It’s a split-system type of AC with record-level specs in terms of energy-efficiency, low noise levels, and overall smart integration and reliability.

As with any 12,000 BTU air conditioner, MrCool 12k can cool down spaces up to 600 sq ft. This mini-split does this job with record-level energy efficiency that can save you $1000s in electricity bills in 20-years.

It has the highest SEER rating of any mini-split AC unit. With a 22 SEER rating, the MrCool 12k is the most energy-efficient 12,000 BTU air conditioner. Compared to below 20 SEER rating and 10 EER rated models, the MrCool 12k operates at +25% efficiency; this translates into major long-term energy savings and is also environmentally friendly.

The high 358 CFM airflow ensures the homogeneous cooling effect and further reduces hot spots in up to 600 sq ft area. Other similar 12,000 BTU units generate less than 300 CFM airflow.

The noise levels are whisper quiet. With 23.5/31.5/38 dB noise levels for low/mid/high fan speed settings, respectively, the MrCOOL 12k is the quietest 12,000 BTU air conditioner. It’s two classes quieter than the quietest window and portable AC units capable of generating 12,000 BTU of the cooling effect.

The only drawback of MrCOOL 12k is the drawback every mini-split has: Higher price than less energy-efficient units and installation. MrCOOL 12k is a DIY unit; with little technical skills, you can install it yourself and save on installation costs.

The price of $1,500 does seem high at first but mini-splits last 5-10 years longer than any other 12,000 BTU air conditioners, and the extreme energy-efficiency will likely save up more than $2500 in 20-years in electricity bills alone.

All in all, the spec-by-spec analysis puts the MrCOOL 12k DIY mini-split on the absolute #1 place. It is unquestionably the best, the most energy-efficient and the quietest 12,000 BTU air conditioner currently on the market:

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2. Whynter Elite ARC-122DS: Best 12,000 BTU Portable Air Conditioner

Whynter Elite ARC-122DS is the most energy-efficient 12,000 BTU portable air conditioner. The advantage of portable units is that you can easily move them from room to room, they don’t require installation, and can provide powerful 12,000 BTU cooling output.

To produce 12,000 BTU output, Whynter Elite ARC-122DS requires only 1000 W. That means it has a 12 EER rating; +40% above the 8.5 EER average for a portable air conditioner. For comparison, standard portable AC units require 1400W to produce 12,000 BTU output. With Whynter Elite ARC-122DS you save about 0.4 kWh 0r 6 cents every hour.

The noise levels are way below the average as well. With up to 52 dB, this is one of the quietest portable AC units that can generate 12,000 BTU. This in part due to lower 155 CFM airflow; the 155 CFM generates less air swirling noise than comparable 200+ CFM units.

The SEER rating – seasonal EER rating – is 13. That’s great for portable units but they cannot be compared to the extreme energy-efficiency of 12,000 BTU mini-splits.

In short, the Whynter Elite ARC-122DS is the ultimate 12,000 BTU portable AC unit. It has superb energy-efficiency, very low noise levels, and is available for less than $600:

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3. Midea U Inverter 12k: Best 12,000 BTU Window Air Conditioner

Midea U Inverter 12k is the revolutionary 12,000 BTU window air conditioner. The U-shaped design that lets in more natural light is the first thing people notice. The truly important parts are the superb energy-efficiency and record level low noise generation for a window unit; both thanks to the advanced inverter compressor.

Superb energy efficiency: Midea U Inverter 12k has a combined EER rating of 15. That’s way above the 9.5 EER rating average for 12,000 BTU window air conditioners. In fact, the Midea U Inverter 12k needs only 890W to generate the massive 12,000 BTU cooling output. That’s an even lower wattage requirement than the best mini-splits.

Midea U Inverter 12k has two super-quiet settings. At low speed, it generates 147 CFM airflow and operates at 42 dB noise levels; these alone are outstanding metrics for a 12,000 BTU window AC unit. On top of that, at high speed, the total airflow output is 464 CFM; above the highest airflow of the mini-splits. It generates only 51 dB even when pushing that massive airflow.

The revolutionary U-shaped design of the window unit has been kindly regarded as one of the best innovations in window AC units. It enables for more natural light, makes the installation very easy, and you can even use the kit to operate the Midea U Inverter 12k with open or closed window.

All in all, Midea U Inverter 12k is a tremendous 12,000 BTU window air conditioner. Thanks to the advanced inverter compressor, it scores high scores for energy-efficiency, low noise levels, and even looks quite aesthetic when mounted on a window sill:

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4. Senville SENL-12CD: Cheap 12,000 BTU Ductless Mini-Split AC Unit

Senville SENL-12CD is the cheap 12,000 BTU mini-split alternative to some of the more expensive units. The key part is that the specs should be at least decent; Senville SENL-12CD has some super specs like low noise levels and high energy-efficiency.

The fact that it costs only $800; only about $300 more than less energy-efficient and noisier window and portable air conditioners is its strongest selling point. In less than 5 years, the higher energy-efficiency will cover those $300 and in the next 15 years, you will save quite a lot on electricity bills.

Senville SENL-12CD has a SEER rating of 19. That’s quite a lot for a 12,000 BTU below $1,000 mini-split. Comparatively, the most efficient portable AC has a SEER rating of 13.

Mini-splits like Senville SENL-12CD are also the quietest 12,000 BTU type of air conditioners. They don’t produce 50 dB noise levels like window and portable AC units with indoor compressors; mini-splits have an outdoor compressor, and the indoor air handler generates less than 40 dB. In the case of Senville SENL-12CD, the complete noise level interval is 28.5/30/38 dB. That’s on par with the quietest #1 MrCOOL 12k DIY unit.

In short, the Senville SENL-12CD is a cheaper variation of the best 12,000 BTU mini split units. It has not only decent but superb specs and costs about $800; way below the price point of most 12,000 BTU mini split:

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5. Frigidaire FFPH1222U1: Best 12,000 BTU Portable AC Unit With Heater

Frigidaire FFPH1222U1 is one of the most well-known 12,000 BTU portable air conditioners. The fact that it’s made by Frigidaire is a good guarantee for reliability. On top of that, the Frigidaire FFPH1222U1 is a 12,000 BTU air conditioner with a heater; one of the few portable units that can be used in the summer as well as in the winter as a supplemental heating source.

This tried-and-tested unit can use the 12,000 BTU of cooling power to cool down rooms up to 600 sq ft. To produce 12k BTU, the Frigidaire FFPH1222U1 uses up to 1320 W of power. That’s not as energy-efficient as most of the other best 12,000 BTU units on this list. Its combined EER rating (CEER rating) is 9.9 which is not ideal.

The optimized airflow (206/224/241 CFM) and quiet Frigidaire compressor make it one of the most silent 12,000 BTU portable units. Its highest noise level is 52 dB; much below 60 dB of the standard 12,000 BTU units.

The addition of a heater is a pro for everybody who requires optional supplemental heating in the winter. This is not a stand-alone heater, but it can produce much more heating than conventional space heaters. Essentially, it works as a 12,000 BTU AC heat pump.

All in all, Frigidaire FFPH1222U1 is the classic tried-and-tested 12,000 BTU air conditioner that is both reliable and has a silent operation. The energy-efficiency is not ideal but the addition of a heater makes the Frigidaire FFPH1222U1 very appealing for people in need of supplemental heating in the winter:

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6. TOSOT 12,000 BTU: Energy-Efficient 12k BTU Window Air Conditioner

TOSOT is a brand that primarily makes watches. However, the fine engineering that goes making the best watches, is also useful when making air conditioners. The TOSOT 12,000 BTU is one of the most energy-efficient air conditioners with a 12.0 EER rating.

To produce 12,000 BTU of cooling output, the TOSOT 12,000 BTU requires only 1000 watts of power input. That translates into a 12.0 EER rating; one of the highest EER ratings of any portable window air conditioner.

The problem all window air conditioners have, including 12,000 BTU units, is the potential for higher noise levels. With 65/67/69 dB, the TOSOT 12,000 BTU is not one of the quietest units. The higher noise levels are the major con when choosing TOSOT 12,000 BTU window AC unit.

Nonetheless, if you don’t have problems with a bit noisy operation, the high energy-efficiency can be super useful if you want to lower cooling electricity bills. The cost of the TOSOT 12,000 BTU air conditioner is also much more affordable compared to mini-splits:

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That’s it for 12,000 BTU AC units. The mini-splits are the best overall choice, and window, as well as portable air conditioners, can be used to produce 12,000 BTU of cooling output as well.