What does a Cooper & Hunter submittal list for noise?
A Cooper & Hunter submittal lists two noise rows per system: "Indoor noise level (Hi/Med/Lo)", three dB(A) figures for the head, and "Outdoor noise level (Max)", a single dB(A) figure for the condenser.
Each sheet is titled with both model numbers, such as "CH-RES12-230VO + CH-RH12MASTWM-230VI", and the figures belong to that pair. No sheet we opened gives a microphone distance, a room, a test standard or the operating mode, and none carries a print date on its face.
The 2025 R454B leaflets for slim duct and floor ceiling units head the condenser row "Outdoor Noise Level (Sound Pressure)", so the outdoor figures are sound pressure by Cooper & Hunter's own label. No document puts that label on an indoor row. Lining these numbers up against another maker's is rough at best (comparing decibel ratings).
Which Cooper & Hunter mini splits are current?
Cooper & Hunter's current US wall units are R454B systems in three series, Astoria (plus Astoria Pro), Olivia (plus Olivia Midnight) and MIA New York, sold with regular or Hyper Heat condensers.
Astoria and Astoria Pro heads run from 6,000 to 36,000 BTU, and most sizes work on single or multi-zone systems. The Pro adds what its product pages call a "Refrigerant Sensor and Humidity Sensor". Olivia covers the same span, with 115V heads at 9,000 BTU and at 12,000; the Olivia Midnight is the black version at 9,000 to 24,000 BTU.
The MIA New York is a one-head, single-zone system from 6,000 to 24,000 BTU, in 115V and 230V, with its own matched CH-RLS condensers rated for heating down to 5°F. The regular RES and REL condensers are rated to -13°F, and the Hyper Heat RHP condensers to -22°F.
The archived site pages also still showed older R410A heads under Residential and the Sophia series under Discontinued. Both appear further down, outside the R454B rankings.
What is the quietest Cooper & Hunter mini split on low fan?
The Cooper & Hunter mini splits with the lowest low-fan figure are the Astoria 09 and Astoria 12 heads on regular RES condensers, at 18 dB(A); the Astoria Pro 12 matches it.
Here is the "Lo" figure, in dB(A), for each R454B wall pair with a submittal. Where Astoria and Astoria Pro are named together, both sheets print the same number.
- 6,000 BTU, on the RHP06F9: Astoria and Astoria Pro 22; Olivia 24
- 9,000 BTU: Astoria on RES09 18; Astoria and Astoria Pro on RHP09 20.5; Olivia on RES09 21; MIA 230V 23; MIA 115V 25; Olivia 115V 26.5
- 12,000 BTU: Astoria and Astoria Pro on RES12 18; Olivia and Olivia Midnight on RES12 20; Astoria and Astoria Pro on RHP12 22; MIA 230V and Olivia Midnight on RHP12 22.5; MIA 115V 25; Olivia 115V 26.5
- 15,000 BTU, on the RHP15: Astoria and Astoria Pro 31.5
- 18,000 BTU: MIA 24; Olivia on RHP18 24.5; Astoria and Astoria Pro on RES18 28 and on RHP18 31.5
- 24,000 BTU: Astoria and Astoria Pro on RES24 21.5; Astoria and Astoria Pro on RHP24 27; MIA 27; Olivia and Olivia Midnight on RES24 27.5; Olivia Midnight on RHP24 34.5
- 30,000 BTU, on the REL30: Astoria and Astoria Pro 30.5; Olivia 36
- 33,000 BTU, on the RHP33: Olivia 29.5; Astoria and Astoria Pro 35.5
- 36,000 BTU, on the REL36: Olivia 33.5; Astoria and Astoria Pro 34.5
That 18 shows up only with the regular condensers. Move the same Astoria 12 onto the Hyper Heat RHP12 and its bottom step reads 22, four higher.
How loud is a Cooper & Hunter mini split on high fan?
Cooper & Hunter's R454B wall pairs list 35.5 to 53 dB(A) on high, and the 9,000 BTU MIA New York on 230V has the lowest top figure, 35.5.
These are the "Hi" figures, in dB(A), ranked only against each other:
- 6,000 BTU: Astoria and Astoria Pro 36.5; Olivia 37
- 9,000 BTU: MIA 230V 35.5; MIA 115V 37.5; Astoria and Astoria Pro on RHP09 38; Olivia 115V 40.5; Olivia on RES09 42; Astoria on RES09 43
- 12,000 BTU: Astoria and Astoria Pro on RHP12 36.5; Astoria and Astoria Pro on RES12, and MIA 230V, 38; MIA 115V and Olivia 115V 40.5; Olivia Midnight on RHP12 42; Olivia and Olivia Midnight on RES12 43
- 15,000 BTU: Astoria and Astoria Pro 45
- 18,000 BTU: MIA, Olivia, and Astoria or Astoria Pro on either condenser, all 45
- 24,000 BTU: Astoria and Astoria Pro on RES24 or RHP24 43.5; MIA 45; Olivia and Olivia Midnight on RES24 48.5; Olivia Midnight on RHP24 49.5
- 30,000 BTU: Astoria and Astoria Pro 45.5; Olivia 52
- 33,000 BTU: Olivia 52.5; Astoria and Astoria Pro 53
- 36,000 BTU: Astoria and Astoria Pro 49; Olivia 51
The Astoria 09 on the RES09 is the odd one: 18 at the bottom, 43 at the top, a 25 dB(A) spread. A head that will spend hot afternoons near full speed should be chosen from this list, and one that idles through the night from the list above.
How loud is a Cooper & Hunter outdoor unit?
Cooper & Hunter's single-zone R454B condensers list 52.5 to 63.5 dB(A) at maximum in the wall submittals, lowest for the CH-RES09-230VO and the 115V MIA condenser at 52.5.
Outdoor figures, in dB(A), ranked against other condensers only:
- 6,000 BTU: CH-RHP06F9-230VO 53
- 9,000 BTU: CH-RES09-230VO and CH-RLS09MIA-115VO 52.5; CH-RES09-115VO 53; CH-RLS09MIA-230VO 53.5; CH-RHP09-230VO 56
- 12,000 BTU: CH-RES12-115VO 53; CH-RLS12MIA-230VO and CH-RLS12MIA-115VO 54; CH-RES12-230VO 54 on Olivia sheets, 56 on Astoria sheets; CH-RHP12-230VO 56
- 15,000 BTU: CH-RHP15-230VO 59
- 18,000 BTU: CH-RLS18MIA-230VO 56; CH-RES18-230VO 58; CH-RHP18-230VO 59
- 24,000 BTU: CH-RES24-230VO 58 on Astoria sheets, 60 on Olivia sheets; CH-RLS24MIA-230VO 59.5; CH-RHP24-230VO 61 or 61.5
- 30,000 to 36,000 BTU: CH-REL30-230VO 61 or 61.5; CH-REL36-230VO 63; CH-RHP33-230VO 63.5
Multi-zone condensers carry one figure each on their product pages. The regular CH-R18MES-230VO lists 59.5, the CH-R28MES-230VO 61, the CH-R36MES-230VO 64.5, the CH-R48MES-230VO 63 and the CH-R60MES-230VO 65. Among Hyper Heat multi-zone units, the CH-RHP19M-230VO and CH-RVHP19M-230VO list 61.5, the RHP28M and RVHP28M 61, and the 36M, 48M and 55M models of both lines 65.
Does the outdoor unit change a Cooper & Hunter head's decibels?
Yes. Cooper & Hunter prints one submittal per head and condenser pair, and the indoor figures move with the condenser: the Astoria 12 lists 38/33/18 dB(A) on the RES12 and 36.5/32.5/22 on the RHP12.
The pattern repeats elsewhere. The Astoria 09 reads 43/31/18 on the RES09 and 38/33/20.5 on the RHP09. The Olivia Midnight 12 reads 43/37/20 on the RES12 and 42/35.5/22.5 on the RHP12. In all three of these examples, the regular pair posts the lower bottom step and the Hyper Heat pair the lower top step. Cooper & Hunter gives no reason.
Condenser figures shift too. The CH-RES12-230VO lists 56 on the Astoria sheets and 54 on the Olivia sheets; the CH-RES24-230VO lists 58 and 60. When an installer quotes a system, ask for the submittal titled with both of its model numbers.
Is the Cooper & Hunter Astoria quieter than the Olivia?
Yes, at most sizes. On the same condenser the Astoria lists lower figures on all three steps at 12,000, 24,000 and 30,000 BTU, while the Olivia has the lower low step at 18,000, 33,000 and 36,000 BTU.
At 12,000 BTU on the RES12 the gap is wide: 38/33/18 for the Astoria against 43/37/20 for the Olivia. At 24,000 BTU it is 43.5/39.5/21.5 against 48.5/43.5/27.5. Outdoors the two sheets disagree about one condenser: the CH-RES12-230VO reads 54 for the Olivia and 56 for the Astoria, while the CH-RES24-230VO reads 60 for the Olivia and 58 for the Astoria.
At 9,000 BTU on the RES09 the two split the steps. The Olivia is one lower on high, 42 against 43, and the Astoria lower on medium and low, 31 and 18 against 36 and 21. Both pairs list 52.5 outdoors.
Are Cooper & Hunter Hyper Heat condensers louder?
Yes, slightly. At each size Cooper & Hunter's Hyper Heat RHP condensers list the same or a higher maximum than the regular RES units, from 56 against 52.5 at 9,000 BTU to 61.5 against 58 at 24,000.
What the extra decibels buy is heating range. The RHP submittals give a heating floor of -22°F; the RES and REL sheets stop at -13°F, and the MIA sheets at 5°F. At 12,000 BTU on the Astoria sheets, the RHP12 and RES12 both list 56.
For a house where winter is the reason to buy, the cold-climate mini split picks put that heating range against other brands.
How quiet are Cooper & Hunter cassettes, consoles and ducted units?
Cooper & Hunter's R454B cassettes, floor consoles, slim ducts, air handlers and floor ceiling units list low-fan figures from 25.5 dB(A), shared by the CH-RSH09MMC floor console and the CH-RS24MAHU air handler, up to 48.
These come from the product pages, which print one "Indoor Noise Level H/M/L" per head without naming the condenser. Each type is kept to its own line, because a ducted unit's sound reaches the room through grilles and ductwork.
- Ceiling cassette, H/M/L: CH-RH09MCT 40/37.5/26; CH-RH12MCT 43.5/40.5/27.5; CH-RH18MCT 44.5/41/27.5; CH-RH24MCT 45/42.5/33.5; CH-RH36LCCT 52/47.5/40; CH-RH48LCCT 52/49.5/41.5
- One-way cassette, H/M/L: CH-RSH06-12MCT1W 41/37/33; CH-RSH18MCT1W 44/41.5/31
- Mini floor console, H/M/L: CH-RSH09MMC 41/37.5/25.5; CH-RSH12MMC 40.5/37/26.5; CH-RSH16MMC 43.5/40.5/30.5
- Slim duct, H/M/L: CH-RS06-12MDT-MS 36/34.5/32.5; CH-RS18MDT-MS 40/39/38; CH-RS24MDT-HS 40/37/35; CH-RS36LCDT-HS 45/40/34; CH-RS48LCDT-HS 51/46/42; CH-RS60LCDT-HS 52/48/42
- Air handler, H/M/L: CH-RS18MAHU 42.5/37.5/30; CH-RS24MAHU 43.5/40/25.5; CH-RS30MAHU 44/41/26; CH-RS36LCAHU 47/42/30.5; CH-RS48LCAHU 54.5/51/48; CH-RS60LCAHU 53/48/33.5
- Universal floor ceiling, H/M/L: CH-RSH18MFC 42.5/39.5/30.5; CH-RSH24MFC 49/45/34; CH-RSH36LCFC 51/45.5/39; CH-RSH48LCFC 53/48.5/39; CH-RSH60LCFC 54.5/49/42
The CH-RSH cassette models at 12,000 to 48,000 BTU print the same figures as the CH-RH models of matching size. The slim ducts list a tight range: the 18,000 BTU unit moves only from 40 to 38 between high and low.
What happened to the Cooper & Hunter Sophia?
The Cooper & Hunter Sophia wall heads sit under "Discontinued" on the US site in each archived capture we read from late 2025 and early 2026, so none is ranked here.
For owners comparing an installed Sophia with a replacement, its pages listed CH-09SPH-230VI and CH-12SPH-230VI at 36.5/30/25 H/M/L and CH-18SPH-230VI at 43/38/32. The matching condensers listed 55.5 for the CH-09SPH-230VO and 57.5 for the CH-12SPH-230VO.
The same captures still showed R410A Astoria, Olivia and MIA New York heads under Residential, paired with HPR, ES and EL condensers. Cooper & Hunter's 2024 Olivia leaflet, for one, gives the 6,000 BTU CH-06MOLVWM-230VI 38.5/33/20.5 dB(A) and its CH-HPR06F9-230VO condenser 53.5, labelled sound pressure. We left the R410A systems out of the rankings because they use the older refrigerant and older documents.
Does a Cooper & Hunter mini split have a quiet mode?
Yes. Cooper & Hunter remotes have a Silence function, switched on by holding a remote button for more than two seconds, and the Astoria remote manual lists "Silence" as a fan speed of 1%.
On that manual's fan scale, Silence is 1% and LOW starts at 21%. Cooper & Hunter warns that Silence runs the compressor at low frequency and "may result in insufficient cooling and heating capacity". Pressing On/Off, Mode, Sleep, Turbo or Clean cancels it.
No wall-unit submittal gives a figure for Silence. The 2025 floor ceiling leaflet does, with a five-step "Turbo/Hi/Mi/Lo/Si" row: the CH-RSH18MFC on the RHP18 lists 45/42.5/39.5/30.5/29 dB(A), so its Silence step is 1.5 below Lo on paper. Sleep is a separate function, which the owner's manual describes as a way to cut energy use overnight.
Why is my Cooper & Hunter mini split making noise?
A Cooper & Hunter mini split makes several noises its owner's manual calls normal, among them a rushing air sound as the louver resets, squeaking from parts expanding in heat mode, and low hissing from refrigerant.
The R454B Astoria owner's manual adds that hissing when the system starts, stops or defrosts "is normal and is caused by the refrigerant gas stopping or changing direction". It also says a buzzing sound at power-up shows the unit started normally, and that the outdoor unit "will make different sounds based on its current operating mode."
Loud or abnormal sounds are a different matter. The manual lists them beside burning smells and damaged wiring as reasons to turn the unit off at once and call an authorized service provider, not to attempt a fix yourself.
