3 Quietest Mini Split AC Units For Bedroom (Below 39.5 dB Noise)


A lot has been said about the advantages of mini split air conditioners. One of the key advantages (besides super high energy efficiency levels and ductless installation) mini splits have are extremely low noise levels. If you want to use a mini split in the bedroom, however, you would do prefer the quietest mini split AC possible, right?

To help you out, we have made a shortlist of the super quiet mini split AC units. These units are the best mini splits for bedroom due to their very silent operation.

This selection is based primarily on the low noise levels of the indoor unit (air handler) and secondarily on the low noise levels of the outdoor unit. You can check these whisper-quiet mini split heat pumps and AC units, complete with spec-by-spec comparison and reviews further on.

components of a quiet mini split air conditioner
To pick a quiet mini split, always check the indoor noise levels generated by the indoor air handler at 3 different settings (Hi/Mi/Lo).

Here’s the deal with mini splits:

These are split system units. That means they have an outdoor unit and an indoor unit (air handler). When checking which ductless mini split is the quietest, you have to take both of these units into account:

  • Outdoor unit is the loud one because it contains the compressor. If you are looking for the best bedroom quiet mini split AC unit, however, the noise of the outdoor unit is not all that important.
  • Indoor unit or air handler is the silent part. This is the important part when looking for which mini split air conditioner is the quietest and best fit for a bedroom.

decibels leves of mini split indoor vs outdoor unit

Before we look at the list of the quietest mini split air conditioners and heat pumps, let’s first look at the benchmark noise levels. We will also quickly look over other specs you need to check before buying these super quiet mini splits (BTU capacity and energy efficiency ratings (SEER, HSPF), installation).

Note: One very valuable tip for a quiet mini split we explain in air conditioner sizing (BTU capacity) is to pick a little larger mini split than you need. That will enable you to run the AC unit in a low and medium fan speed setting that produces lower noise levels than running a mini split at 100% output capacity.

We will start with the most important noise levels we need to look out for when picking the best mini split for a bedroom:

Indoor Air Handler Noise Levels (Most Important Spec For Quiet Mini Split AC Units)

In any air conditioner, the noisiest part of the compressor. The reason why mini splits are so quiet is that the compressor is located in the outdoor unit. That, however, does not mean that the indoor air handler is completely silent.

The primary source of noise in indoor units is airflow and fan motor. When the mini split is blowing cool air, that flow of air causes wooshing sounds. If the design of the indoor mini split unit is not adequately optimized to reduce the noise levels generated by the airflow, you can even see above 50 dB indoor noise levels.

Now, it is key to understand that every mini split (even the most silent units) has 3 speed settings: Low, Medium, High. These speed settings correspond with increasing airflow and thereby with increasing noise levels.

How to know which mini split is quiet?

Well, you open the specification sheet and check the indoor noise levels. Example of this line in the specs sheets:

Indoor noise levels (Hi/Mi/Lo): 45/38/30 dB. This means that the highest setting will generate 45 dB of noise, the middle setting will generate 38 dB and the lowest setting will generate 30 dB noise levels.

How to tell if you are looking at a very quiet unit?

You have to have an idea of what amount of noise an average mini split makes. Here are some helpful benchmark noise levels for mini split’s indoor air handler:

  • High setting benchmark noise levels: 40-50 dB.
  • Medium setting benchmark noise levels: 35-42 dB.
  • Low setting benchmark noise levels: 25-34 dB.
sound rating of mini split air conditioners and heat pumps
Illustration of how silent the very low noise level mini splits are. Photo by Bosch. You can check the quietest Bosch mini split in the list below (#3 Bosch Climate 5000 12k).

If you see a mini split with below 40 dB noise levels on a high setting, you know you are looking at a quiet mini split heat pump. The same is true if you are looking at a unit with below 35 dB medium setting noise levels and below 25 dB low setting noise levels.

In the comparison table of the quietest mini split air conditioners below, you can see that all recommended units have super low noise levels for all settings (below 40 dB, 35 dB, 25 dB for high, medium, and low settings, respectively).

Note: The high setting is always the loudest (due to the highest airflow). If you are trying to choose the best quiet ductless mini split for the bedroom, the most important spec you should check is the indoor unit’s noise levels at a high setting. Anything above 40 dB is not considered quiet and you might have problems sleeping with a loud mini split running in your bedroom.

Let’s look at similar benchmark levels for the outdoor units:

How Much Noise Does Mini Split Outdoor Unit Generate?

The outdoor unit contains an air compressor. This is usually the noisiest part of every air conditioner. The advantage of the split system is that you don’t have to have this compressor in your bedroom (as is the case with portable and window air conditioners).

Note: Look for inverter compressors. Inverter compressors are not only more energy efficient than rotary compressors; they are also much quieter.

Nonetheless, if you are looking for the quietest mini split AC unit, it makes sense that you would also like for the outdoor unit to be as silent as possible.

An average mini split outdoor unit will generate 65-70 dB of noise. Anything below 65 dB is considered silent. The quietest mini split on the list below – #1 MRCOOL DIY-12-HP-115B25 – uses a super silent compressor and manages to keep the noise levels even below 60 dB.

Other Key Metrics To Check When Choosing A Quiet Mini Split AC/Heat Pump

With quiet mini splits the focus is obviously on noise levels. However, we must not forget about other factors you need to be aware of when choosing any air conditioner.

These metrics include:

  1. How many BTU mini split do you need? Mini split sizing is important. For most bedrooms or spaces up to 400 sq ft, you should choose either 9,000 BTU or, better yet, a 12,000 BTU mini split. In theory, the 12,000 BTU mini splits have up to 600 sq ft coverage. However, even if you have a 100-200 sq ft bedroom, it makes sense to choose the 12,000 BTU unit. That will enable you to run it at a medium or even low setting which will, as we have seen, drastically lower the indoor noise levels.
  2. SEER rating. SEER rating denotes the cooling energy efficiency. Picking a quiet mini split with a higher SEER rating will result in lower cooling costs. Mini splits are notorious to have very high SEER ratings; ideally, pick a mini split with an 18+ SEER or even 20+ SEER rating.
  3. HSPF rating. HSPF rating denotes the heating energy efficiency. Most mini splits are heat pumps; they can provide heating in the winter in addition to cooling in the summer. You just flip a switch, the refrigeration flow is switched, and you get heating. Units with a higher HSPF rating lower heating costs. Always go for a mini split with at least an 8 HSPF rating. 10+ HSPF rating is perfect.
  4. Installation (DIY). Be mindful of how even a quiet mini split is installed. In many cases, you need a professional installation that can increase the overall costs. To reduce these costs, pick a quiet DIY mini split. With some technical skills (power tools), you can use the installation kit and install a mini split yourself.

With all these in mind, let’s look at the 3 absolutely quietest mini splits currently on the market:

3 Best Quiet Mini Split AC/Heat Pumps


1. Quietest Mini Split On The Market: MRCOOL DIY-12-HP-115B25

Quietest Mini Split On The Market: MRCOOL DIY-12-HP-115B25
Indoor Noise Levels (Hi/Mi/Lo): 38 / 31.5 / 23.5 dB
Outdoor Noise Levels: Below 57.5 dB
Capacity: 12,000 BTU (1 ton)
Coverage Area: Up To 500-600 Sq Ft
SEER Rating: 22 SEER
HSPF Rating: 10 HSPF
Price: $$$$
Rating: 4.8 out of 5 stars

MRCOOL DIY-12-HP-115B25 is considered one of the best mini split AC units in general. The main reason everybody focuses on is the extremely high energy efficiency and the easy DIY installation kit. On top of this, however, it has a very silent operation. Overall, it is the quietest mini split current on the market.

The indoor noise levels are very low:

  • 38 dB on high setting. Below 40 dB.
  • 31.5 dB on medium setting. Below 35 dB.
  • 23.5 dB on low setting. Below 25 dB.

That means that the MRCOOL DIY-12-HP-115B25 has the overall lowest noise levels on the whole load interval. The outdoor unit with the inverter compressor is way below 65 dB as well (up to 57.5 dB, to be exact).

MRCOOL DIY-12-HP-115B25 can produce up to 12,000 BTU cooling output and has up to 600 sq ft coverage. This is a perfect bedroom mini split; if you put it in a 100-300 sq ft bedroom, you can run it on a low 23.5 dB setting or medium 31.5 dB setting.

The key advantages MRCOOL DIY-12-HP-115B25 has are extremely high cooling energy efficiency (22 SEER rating) and very high heating energy efficiency (10 HSPF rating). On top of that, this is the easiest DIY mini split you can install yourself.

The drawback is a little higher than the average upfront cost. This additional cost, however, makes for a smart investment. With the DIY installation (you need a standard 120V outlet) and the extremely low running costs, the mini split will pay for itself in less than 5 years.

Overall, MRCOOL DIY-12-HP-115B25 is the quietest mini split that is perfect for bedrooms. With superb specs all around and the DIY installation kit, this is the best mini split to get overall:

MrCool DIY-12-HP-115B25 Review

Pros

  • Extremely low indoor noise levels (38 / 31.5 / 23.5 dB)
  • Record low outdoor noise levels (below 57.5 dB)
  • Extremely high cooling efficiency (22 SEER) and very high heating efficiency (10 HSPF)
  • Very low running costs and reliable operation
  • Easiest DIY installation kit
Cons

  • Higher-than-average price
  • 12,000 BTU is too much for very small bedrooms (below 100 sq ft)

2. Super Quiet Mini Split Heat Pump: Cooper & Hunter Sophia 12k

Super Quiet Mini Split Heat Pump: Cooper & Hunter Sophia 12k
Indoor Noise Levels (Hi/Mi/Lo): 36 / 32 / 23 dB
Outdoor Noise Levels: Below 60.3 dB
Capacity: 12,000 BTU (1 ton)
Coverage Area: Up To 500-600 Sq Ft
SEER Rating: 21.5 SEER
HSPF Rating: 11.2 HSPF
Price: $$$$
Rating: 4.6 out of 5 stars

Cooper & Hunter Sophia series is one of the most durable and reliable mini splits on the market. With extremely low noise levels and reasonable price, it is also the cheapest quiet mini split that fits well into bedrooms.

Cooper & Hunter Sophia 12k has a 12,000 BTU cooling output. Noise-wise, it has a very low 36 / 32 / 23 dB noise profile for Hi/Mi/Lo setting, respectively.

The outdoor unit is also very quiet (below 60.3 dB), despite the use of a rotary compressor.

It has an operation range for cooling between 62°F – 90°F (indoor temperature) and -13° – 122°F (outdoor temperature).

As all Sophia series mini splits by Cooper & Hunter, their 12,000 BTU has a very high energy efficiency (cooling: 21.5 SEER, heating: 11.2 HSPF). The heating efficiency is especially high; that’s why Cooper & Hunter Sophia 12k is considered one of the best quiet mini split heat pumps.

For heating, it has a rated input of only 960W (that’s 8.4 amps for a 115V model). You can also choose 9,000 BTU, 18,000 BTU, and up to 36,000 BTU units from the Sophia series; all of them have very low indoor noise levels.

All in all, the Cooper & Hunter Sophia series mini splits are the go-to choice for affordable and quiet mini splits:

Cooper & Hunter Sophia Review

Pros

  • Quiet indoor operation (36 / 32 / 23 dB noise levels)
  • Lower than 65 dB outdoor unit noise levels (below 60.3 dB, to be exact)
  • Sophia series includes several sizes of mini splits; from 9,000 BTU to 36,000 BTU
  • Extremely high heating efficiency (11.2 HSPF) and very high cooling efficiency (21.5 SEER)
  • Affordable price (below $1,300 for 12,000 BTU unit)
Cons

  • It has a rotary compressor; an inverter compressor would be better
  • DIY installation kit is included but you will have to have considerable technical skills to install it yourself

3. Quietest Bosch Mini Split Inverter: Bosch Climate 5000 12k

Quietest Bosch Mini Split Inverter: Bosch Climate 5000 12k
Indoor Noise Levels (Hi/Mi/Lo): 39.5 / 34 / 25 dB
Outdoor Noise Levels: Below 61.8 dB
Capacity: 12,000 BTU (1 ton)
Coverage Area: Up To 500-600 Sq Ft
SEER Rating: 20.7 SEER
HSPF Rating: 9.6 HSPF
Price: $$$$
Rating: 4.5 out of 5 stars

Bosch is one of the best and most recognizable HVAC brands. With Bosch Climate 5000 12k, they have made one of the quietest ductless mini split on the market with below 40 dB indoor noise levels. A Bosch mini split is always a good idea.

The indoor noise levels of Bosch Climate 5000 12k are 39.5 / 34 / 25 dB for Hi/Mi/Lo fan speed setting. These noise levels are way quieter than the benchmark decibel levels of most mini split air conditioners.

The outdoor unit makes up to 61.8 dB noise levels; this is also below the 65-70 dB noise levels standard mini splits have.

Efficiency-wise, you can see that the Bosch Climate 5000 12k has a very high 20+ SEER rating (20.7 SEER, to be exact) and a fairly high 9.7 HSPF rating. Ideally, you would hope for the heating efficiency HSPF rating to be above 10.

Bosch, however, offers only the 12,000 BTU model as a quiet bedroom mini split. You will also have to use a non-standard 230V electric circuit for installation.

All in all, the Bosch Climate 5000 12k is a good example of a durable quiet mini split that will easily last for 10+ years:

Bosch Climate 5000 12k Review

Pros

  • Very low below 40 dB noise levels for all settings
  • Below 65 dB outdoor unit noise levels
  • Very high cooling efficiency (20.7 SEER)
  • Bosch is considered one of the best HVAC companies that makes durable and reliable units
Cons

  • You need a 230V electric circuit for installation
  • HSPF rating is good but not above 10 (9.7 HSPF, to be exact)
  • Bosch has it’s price (up to almost $1,500)

This has been a quick view of mini split noise levels. Hopefully, with everything considered, you now have adequate familiarity with how quiet modern mini splits can be and you can choose one yourself.

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