Mitsubishi Electric Trane HVAC US publishes a noise figure for every current M-Series mini-split: an indoor sound pressure level for each fan speed, in cooling and in heating, and an outdoor figure at rated conditions. The catch is that the submittals print the indoor figures as a bare list, such as "19 , 22 , 30 , 37 , 43", with no speed names. The names are in Mitsubishi's technical and service manuals, and that is where this page takes them from.
Below is every current US M-Series unit with a published figure: wall-mounted, floor-mounted and ceiling cassette, plus their outdoor units, grouped so that only like is compared with like. To see how Mitsubishi sits against other brands, see our quietest mini-splits guide; we do not rank other brands here.
Our picks are listed above, with full specifications for each.
How Mitsubishi rates noise
Every submittal has two indoor rows, "Sound Pressure Level [Cooling]" and "Sound Pressure Level [Heating]" in dB (A), and two outdoor rows, "Sound Pressure Level, Cooling" and "Sound Pressure Level, Heating". The outdoor rows are footnoted to rating conditions: 95°F outside for cooling and 47°F for heating.
The service manuals fill in what the submittals leave out. They label each indoor figure by fan speed, most state "Test conditions are based on AHRI 210/240", and for the wall units they draw the microphone 39-3/8 inches (1 m) from the unit. They also carry a warning worth repeating in full: "The sound level is measured in an anechoic room where echoes are few, when compressor stops. The sound may be bigger than displayed level under actual installation condition by surrounding echoes. The sound level can be higher by about 2 dB than the displayed level during cooling and heating operation."
The speed names differ by series, which decides what can be ranked against what:
- Five speeds, Quiet to Super High: FX Deluxe, GX Premier, EX Designer and the MFZ-KX floor unit.
- Four speeds, Low to Super High: HX, JX (115V) and WX. These have no Quiet speed.
- Four speeds, SLow to High: the MLZ-KX EZ FIT one-way cassette.
- Three figures: the SLZ-AF four-way cassette, whose manual heads the row "(LoLo-Lo-Mid-Hi)" but prints only three values, so we list them lowest to highest without names.
Low is the one label every wall series shares, so it is the fairest way to line them up. For why figures from different brands line up even less well, see comparing decibel ratings.
Which models are current
Mitsubishi moved its M-Series to R454B refrigerant. Its consumer site, mitsubishicomfort.com, now lists the FX, GX, HX, EX, JX and WX wall units, the MFZ-KX floor unit and the MLZ-KX and SLZ-AF cassettes. The R410A models many buyers still search for, the MSZ-FS, GS, GL, HM and EF, are listed as Phased Out or Obsolete on Mitsubishi's MPro portal, though their submittals remain on MyLinkDrive. Contractors may still have stock, so if you are quoted one, its submittal applies, not the figures below. Our category guide still uses the R410A MSZ-FS09NA as a reference: 20 dB(A) on its lowest speed and 48 dB(A) outdoors in cooling.
Several current indoor units are also mid-revision: MPro marks the U1 version of the FX, MFZ-KX and MLZ-KX "Phased Out" with a U2 "Coming Soon", and the HX09 has a successor, the MSZ-HX09NL2, "Ready for Preorder". We checked the HX09NL2 and EX09NL2W submittals and they print the same figures as the units they replace.
Every wall unit on Low, in cooling, quietest first
Figures are from each single-zone system submittal. GX06 and GX04 are sold for multi-zone systems only; the GX04 submittal lists 26 dB(A) on Low, and we found no figure for the GX06.
- 6,000 BTU: FX06 23.
- 9,000 BTU: GX09, HX09, JX09 and WX09 22; FX09 and EX09 23.
- 12,000 BTU: GX12, HX12, JX12 and WX12 22; FX12 and EX12 24.
- 15,000 BTU: FX15 and EX15 31; GX15 32.
- 18,000 BTU: HX18 30; FX18 31; WX18 32; EX18 and GX18 33.
- 24,000 BTU: HX24 and WX24 33; FX24 34; GX24 37.
- 30,000 and 36,000 BTU: GX30 and GX36 37.
The five-speed units on Quiet
Among the wall units, only the FX, GX and EX have a Quiet speed, so only they appear here.
- 6,000 BTU: FX06 20.
- 9,000 BTU: GX09 19; FX09 20; EX09 21.
- 12,000 BTU: GX12 19; FX12 20; EX12 21.
- 15,000 BTU: GX15 26; FX15 27; EX15 28.
- 18,000 BTU: FX18 27; GX18 28; EX18 30.
- 24,000 BTU: FX24 27; GX24 30.
- 30,000 and 36,000 BTU: GX30 and GX36 30.
If the head is going in a bedroom, this is the list that matters; our bedroom mini-split guide explains why the lowest speed is the figure you sleep through.
Super High, in cooling
This is what you hear while the unit pulls a hot room down. The order changes: the EX Designer, which trails on Quiet, is lowest at every size it comes in.
- 9,000 BTU: EX09 42; GX09, HX09, JX09 and WX09 43; FX09 44.
- 12,000 BTU: EX12 42; FX12 44; GX12 and WX12 45; HX12 and JX12 47.
- 15,000 BTU: EX15 42; FX15 45; GX15 51.
- 18,000 BTU: EX18 43; FX18 45; HX18 47; GX18 and WX18 49.
- 24,000 BTU: HX24 and WX24 50; FX24 and GX24 53.
For a living room, where the head runs on Low to High with people talking, our living room mini-split guide reads the 18,000 and 24,000 BTU heads at those speeds.
Floor-mounted and ceiling cassettes
These are ranked only within their own series.
MFZ-KX floor unit, Quiet to Super High, cooling, with SUZ-AA outdoor units: KX09 and KX12 "21 , 27 , 34 , 41 , 46"; KX15 "28 , 33 , 38 , 43 , 47"; KX18 "28 , 33 , 39 , 45 , 50". Used on a multi-zone system the indoor-only submittal lists lower upper speeds, "21 , 25 , 30 , 34 , 38" for the KX09.
MLZ-KX EZ FIT one-way cassette, SLow to High, cooling: KX09 "27 , 31 , 34 , 38"; KX12 "27 , 32 , 36 , 40"; KX18 "29 , 36 , 41 , 47"; and the multi-zone-only KX06 "29 , 31 , 34 , 36".
SLZ-AF four-way cassette, three figures, lowest to highest: AF09 "25 , 28 , 31"; AF12 "25 , 30 , 34"; AF15 "27 , 34 , 39"; AF18 "32 , 40 , 43".
Every outdoor unit, cooling at 95°F, quietest first
These are the figures your neighbors hear. Compare them only with each other.
- 6,000 BTU: MUZ-FX06NLHZ 47.
- 9,000 BTU: MUZ-HX09NL and MUZ-JX09WL 46; MUZ-GX09NL, MUZ-GX09NLHZ, MUZ-WX09NL and SUZ-AA09NL 48; MUZ-FX09NLHZ 49; SUZ-AA09NLHZ 54.
- 12,000 BTU: MUZ-FX12NLHZ, MUZ-GX12NL, MUZ-GX12NLHZ, MUZ-HX12NL, MUZ-JX12WL and SUZ-AA12NL 49; MUZ-WX12NL 51; SUZ-AA12NLHZ 54.
- 15,000 BTU: MUZ-GX15NL, MUZ-GX15NLHZ and SUZ-AA15NL 49; MUZ-FX15NLHZ 51; SUZ-AA15NLHZ 54 or 55 (the SLZ-AF15 submittal prints 54, the EX15 and MFZ-KX15 submittals 55).
- 18,000 BTU: MUZ-HX18NL 49; MUZ-FX18NLHZ 52; MUZ-WX18NL 53; MUZ-GX18NL, MUZ-GX18NLHZ, SUZ-AA18NL and SUZ-AA18NLHZ 54.
- 24,000 BTU: MUZ-HX24NL 54; MUZ-FX24NLHZ, MUZ-GX24NL and MUZ-GX24NLHZ 55; MUZ-WX24NL 57.
- 30,000 and 36,000 BTU: MUZ-GX30NL and MUZ-GX36NL 57.
In heating at 47°F most outdoor units list the same or up to four dB(A) more; the MUZ-WX18NL and MUZ-WX24NL are the exceptions, listing two less.
Multi-zone MXZ units, cooling: MXZ-SM36NL and MXZ-SM36NLHZ 49; MXZ-SM42NLHZ 50; MXZ-2D20NL, MXZ-2D20NLHZ, MXZ-3D24NL, MXZ-SM48NL and MXZ-SM48NLHZ 51; MXZ-4D30NL 53; MXZ-3D24NLHZ and MXZ-3D30NLHZ 56; MXZ-5D36NL, MXZ-5D42NL, MXZ-SM60NL and MXZ-SM60NLHZ 58.
What changes the noise between models
Size, above all. From 15,000 BTU up, the low speeds jump: the GX goes from 19 on Quiet and 22 on Low at 12,000 BTU to 26 and 32 at 15,000, and the HX from 22 on Low at 12,000 BTU to 30 at 18,000. If a 12,000 BTU head will do the room, it will be quieter at night.
The number of fan speeds. The FX, GX and EX get a Quiet speed below Low; the HX, JX and WX do not. At 9,000 and 12,000 BTU the cheaper series match the GX on Low, so the Quiet speed is most of what you pay for, noise-wise.
The outdoor unit you pair. The floor and cassette units use the universal SUZ-AA outdoor units, and choosing the hyper-heating SUZ-AA09NLHZ instead of the SUZ-AA09NL raises the outdoor figure from 48 to 54 dB(A). In the GX series, the hyper-heating outdoor unit lists the same as the standard one.
Mitsubishi's quiet claims, in its words
The GX and EX submittals say: "Quiet: Our indoor units offer whisper-quiet operation as low as 19 dB(A). Our outdoor units are design for ultra quiet operation." Several EX and MXZ submittals say: "Quiet: Outdoor units are as quiet as a typical conversation, and most indoor units are whisper quiet." The MFZ-KX floor unit's submittals list "Powerful Mode", which "adjusts fan speed to quickly bring your room to your desired comfort", so expect it to run near the Super High figure. Most of the wall, floor and cassette submittals list Econo Cool, which "temporarily adjusts the airflow to maintain comfort while using less energy".
What 19 to 57 dB(A) means at home
Every 10 dB(A) sounds roughly twice as loud, so a GX09 on Quiet at 19 should sound about half as loud as the same unit on Med. at 30, if the conditions match. Our decibel chart puts the figures next to everyday sounds, and how quiet is quiet enough gives targets by room. Remember Mitsubishi's own caveat: its indoor figures are taken with the compressor stopped, and it says real operation can add about 2 dB.
Price and installation
Mitsubishi shows no prices on mitsubishicomfort.com; systems are quoted and installed by contractors. Its residential warranty "applies only to Products that are installed by licensed HVAC contractors": 5 years on parts and 7 on the compressor, 10 years if registered within 90 days in an owner-occupied home, and 12 years through a Diamond Contractor.
We did not measure any of these units. Every figure is Mitsubishi's own, quoted from its US submittals and labelled by fan speed from its technical and service manuals, and Mitsubishi says real installations may be louder than its anechoic-room figures.
