Fujitsu, whose US mini-splits are now sold under the AIRSTAGE name by GENERAL HVAC Solutions America, publishes a noise figure for every current single-room system: an indoor sound pressure level for each named fan speed, in cooling and in heating, and an outdoor figure for each mode. It names the speed next to every figure and says where it measured them, which makes its line easy to rank fairly.
Below is every current US AIRSTAGE unit with a published figure, wall-mounted, floor, cassette, ceiling and ducted, plus their outdoor units, grouped so that only like is compared with like. To see how Fujitsu 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 Fujitsu rates noise
Each system submittal has an "Indoor Sound Pressure Level" row in dB (A), split into Cooling and Heating, with one line per fan speed, and an "Outdoor Sound Pressure Level" row for Cooling and Heating. Both carry the same footnote: "Measured values in manufacturer's anechoic chamber. Because of the surrounding sound environment, the sound levels measured in actual installation conditions might be higher than the specified values here."
The design and technical manuals add the geometry. For the Altair 500 wall unit, the "Sound level check point" drawing puts the microphone 40 in (1 m) out from the front of the indoor unit and 32 in (0.8 m) below it. For the outdoor units, the microphone sits 40 in (1 m) from the unit, and the manual's footnote says the outdoor figures were taken in a "semi-anechoic chamber". The capacity ratings on the same sheets state "Test conditions are based on AHRI 210/240 2023."
The speed names differ by series, which decides what can be ranked against what:
- Six speeds, Quiet, Low, Med-Low, Med, Med-High and High: Altair 500 (KPAS1, KPBS1), Orion XLTH (KZAH1) and Orion XLTH+ (KTAP1).
- Four speeds, Quiet, Low, Med and High: Altair 700 (KMAS1), Altair 300 (KNAS1), the Centauri floor unit, both cassettes, the ceiling-suspended unit and the ducted units.
Quiet, Low and High appear on every series, so those are the labels we rank on. For why figures from different brands line up even less well, see comparing decibel ratings.
Which models are current
Fujitsu's product portal, AIRSTAGE Connect, lists the R-32 K-series as current and marks the older R410A outdoor units "(RETIRED)", including the Halcyon AOU9RLS3 and AOU12RLS3H, the LZAS1 and LZAH1 units, the LMAS1 and LPAS1 units and the LUAS1 universal heat pumps. Contractors may still have stock, so if you are quoted one, its own submittal applies.
The Altair 500 is mid-revision: the portal lists each ASUH KPAS indoor unit as "replaced by" a KPBS version. We checked the 9,000 to 30,000 BTU KPBS system submittals and their cooling figures match the KPAS units they replace.
Every wall unit on Quiet, in cooling, quietest first
Figures are from each single-zone system submittal. The Altair 300 comes in 115V (ASLH) and 230V (ASUH) versions with the same indoor figures.
- 9,000 BTU: Altair 500 and Altair 700 19; Altair 300 20; Orion XLTH and Orion XLTH+ 23.
- 12,000 BTU: Altair 500 and Altair 700 19; Altair 300 20; Orion XLTH and Orion XLTH+ 23.
- 15,000 BTU: Orion XLTH and Orion XLTH+ 26.
- 18,000 BTU: Altair 500 26; Altair 300 28; Orion XLTH 30.
- 24,000 BTU: Orion XLTH 30; Altair 500 and Altair 300 31.
- 30,000 and 36,000 BTU: Altair 500 32.
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.
Every wall unit on Low, in cooling
Low is where a head often settles once the room is comfortable. The order changes: the cheapest series leads at the small sizes, and the Orion XLTH+ trails.
- 9,000 BTU: Altair 300 27; Altair 500 29; Altair 700 30; Orion XLTH 31; Orion XLTH+ 35.
- 12,000 BTU: Altair 300 28; Altair 500 29; Altair 700 30; Orion XLTH 31; Orion XLTH+ 35.
- 15,000 BTU: Orion XLTH 31; Orion XLTH+ 37.
- 18,000 BTU: Orion XLTH 33; Altair 300 35; Altair 500 37.
- 24,000 BTU: Orion XLTH 33; Altair 500 37; Altair 300 38.
- 30,000 and 36,000 BTU: Altair 500 39.
Every wall unit on High, in cooling
This is what you hear while the unit pulls a hot room down.
- 9,000 BTU: Altair 500 and Altair 700 40; Altair 300 41; Orion XLTH and Orion XLTH+ 43.
- 12,000 BTU: Altair 700 40; Altair 300 41; Altair 500 42; Orion XLTH 43; Orion XLTH+ 44.
- 15,000 BTU: Orion XLTH and Orion XLTH+ 45.
- 18,000 BTU: Altair 500 and Orion XLTH 44; Altair 300 48.
- 24,000 BTU: Orion XLTH 44; Altair 300 49; Altair 500 51.
- 30,000 and 36,000 BTU: Altair 500 51.
For a living room, where the head runs between Low and High with people talking, our living room mini-split guide reads the 18,000 and 24,000 BTU heads at those speeds.
Floor, cassette and ceiling units
These are ranked only within their own type. Figures are Quiet, Low, Med and High, in cooling, from the single-zone submittals.
Centauri floor unit (AGUH): 9,000 and 12,000 BTU "22, 30, 36, 41"; 15,000 BTU "22, 32, 39, 45". Used on a multi-zone system, the indoor-only submittals list the same 22 on Quiet.
Compact cassette (ACUH): 9,000 BTU "28, 30, 32, 34"; 12,000 BTU "29, 31, 34, 37"; 18,000 BTU "29, 32, 36, 42". A 7,000 BTU version for multi-zone systems lists the same as the 9,000.
Circular flow cassette (AUUH): 18,000 BTU "28, 31, 32, 34"; 24,000 "30, 33, 34, 36"; 30,000 "33, 36, 38, 40"; 36,000 "34, 38, 41, 45"; 42,000 "36, 39, 42, 47"; 48,000 "36, 41, 44, 48".
Ceiling suspended (ABUH): 18,000 BTU "31, 33, 36, 38"; 24,000 "29, 32, 36, 41"; 30,000 "32, 35, 40, 45"; 36,000 "32, 37, 40, 44".
Ducted units
Fujitsu prints the same kind of figure for its ducted air handlers. We keep them apart from the ductless heads, because a ducted unit sits above a ceiling or in a closet, and what reaches the room depends on the ductwork. In cooling, Quiet to High:
- Mid-static duct (ARUH): 12,000 BTU "24, 27, 30, 35"; 18,000 "24, 26, 29, 34"; 24,000 "24, 28, 31, 36"; 30,000 "30, 33, 36, 39"; 36,000 "26, 30, 33, 37"; 42,000 and 48,000 "29, 33, 35, 40".
- Multi-position air handler (AMUH): 12,000 BTU "31, 35, 38, 42"; 18,000 "33, 36, 39, 44"; 24,000 "29, 36, 38, 42"; 30,000 "32, 35, 37, 42"; 36,000 "31, 36, 39, 44"; 48,000 "34, 37, 44, 49".
- Slim duct (ADUH), multi-zone only: 7,000 BTU 24 on Quiet; 9,000 25; 12,000 24; 18,000 and 24,000 29.
Every outdoor unit, cooling, quietest first
These are the figures your neighbors hear. Compare them only with each other.
- 9,000 BTU: AOUH09KMAS1 and AOUH09KTAP1 44; AOLH09KNAS1 and AOUH09KNAS1 45; AOUH09KPAS1 and AOUH09KZAH1 46.
- 12,000 BTU: AOUH12KZAH1 47; AOUH12KMAS1, AOLH12KNAS1, AOUH12KNAS1, AOUH12KPAS1 and AOUH12KTAP1 48.
- 15,000 BTU: AOUH15KZAH1 49; AOUH15KTAP1 51.
- 18,000 BTU: AOUH18KZAH1 47; AOUH18KPAS1 50; AOUH18KNAS1 51.
- 24,000 BTU: AOUH24KZAH1 51; AOUH24KPAS1 and AOUH24KNAS1 55.
- 30,000 and 36,000 BTU: AOUH30KPAS1 53; AOUH36KPAS1 54.
In heating most list the same or up to three dB(A) more; the AOUH15KTAP1 and AOUH24KPAS1 list less. Some submittals print one figure for both modes, including the AOUH09KTAP1, AOUH12KZAH1 and AOUH12KPAS1.
Universal outdoor units, which serve the floor, cassette, ceiling and ducted units, vary with the pairing: AOUH09KUAS1 44; AOUH09KUBS1 44 or 45; AOUH12KUBS1 45 or 48; AOUH18KUAS1 and AOUH24KUAS1 52; AOUH30KUAS1 53 or 55; AOUH36KUAS1 54 or 57; AOUH42KUAS1 55; AOUH48KUAS1 57. The cold-climate XLTH versions list AOUH30KUAH1 and AOUH36KUAH1 53, AOUH42KUAH1 52 and AOUH48KUAH1 54.
Multi-zone outdoor units, cooling: AOUH18KWAH2 47; AOUH18KWAS2 48; AOUH24KWAS3 and AOUH24KWAH3 50; AOUH36KWAS4, AOUH36KWAH4 and AOUH45KWAS5 54.
What changes the noise between models
Size, above all. On Quiet, the Altair 500 goes from 19 dB(A) at 12,000 BTU to 26 at 18,000 and 31 at 24,000. On High it goes from 42 to 44 to 51. If a 12,000 BTU head will do the room, it will be quieter at night.
The series, but not in the order of price. At 9,000 and 12,000 BTU the cheaper Altair 500, 700 and 300 list lower indoor figures than the Orion XLTH and XLTH+, which are built for cold climates. At 18,000 and 24,000 BTU, the Orion XLTH lists the lowest Low figure, the lowest or tied-lowest High figure and the lowest outdoor figure. The Orion XLTH+ pays for its -22°F heating with the highest Low figures at each of its sizes.
The outdoor unit you pair. With the universal outdoor units, the same model can list a different figure with a different indoor unit. The cold-climate XLTH universal units list the same or less than the standard ones at every size and pairing we could compare.
Fujitsu's quiet claims, in its words
Every wall submittal lists "Whisper-quiet operation with sound levels as low as" its lowest indoor figure, from "19dB" on the Altair 500 and 700 to "23dB" on the Orion XLTH and XLTH+. The product pages show the same under "Sound Level: As low as". The feature lists include "Quiet Mode (Indoor Unit)" and a "Sleep Timer", and the Altair 500, Altair 700 and Orion XLTH submittals list a "Low-noise outdoor unit operation mode"; the Orion XLTH+ and floor-unit submittals call it "Outdoor Unit Low-noise operation mode". Fujitsu publishes no separate figure for that mode.
What 19 to 57 dB(A) means at home
Every 10 dB(A) sounds roughly twice as loud, so an Altair 700 09 on Quiet at 19 should sound about half as loud as the same unit on Low 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 Fujitsu's own caveat: its figures come from a chamber built to absorb echoes, and it says real installations might be higher. For a sense of how another maker reports the same kind of figure, see our Mitsubishi mini-split decibels page.
Price and installation
Fujitsu shows no prices on airstagehvac.com; systems are quoted and installed by contractors. Its warranty, as printed on each product page: "7 Year Compressor, 5 Year Parts out-of-the-box Warranty. 10 Year Compressor, 10 Year Parts Warranty when registered within 60 days of installation in a residence." The 12-year version needs a Fujitsu Elite contractor.
We did not measure any of these units. Every figure is Fujitsu's own, quoted from its US submittals with the fan speed and mode it gives, and Fujitsu says real installations might be louder than its anechoic-chamber figures.
