Quietest Mini Split AC Units in 2026 (Below 20 dB) — Full Comparison

The quietest mini split on the market in 2026 is the Fujitsu Halcyon RLS3H series at 18 dB on its lowest indoor fan setting, with the Mitsubishi MSZ-FH and DaikinDERA series tied closely behind at 19 dB. To put that in perspective, normal breathing registers around 10 dB and a whisper at 20 dB — these units are literally quieter than a whispered conversation. If noise is your top priority, any mini split from the "Big Three" (Mitsubishi, Daikin, Fujitsu) with a rated indoor noise below 22 dB will be virtually inaudible in a furnished room.

But here's what the marketing brochures don't tell you: that 18–19 dB rating is measured at the lowest fan speed in a controlled laboratory with zero background noise. In your actual living room, you'll run the unit at medium or high fan speed most of the time to get adequate cooling, which bumps the noise to 35–46 dB. Still quiet — but a very different number than the headline spec. This guide gives you the real-world data so you know exactly what to expect.

What "Below 20 dB" Actually Means

The sub-20 dB ratings that manufacturers advertise deserve some careful unpacking. At 19 dB, a mini split is producing sound energy at roughly the same level as a ticking clock in a quiet room. Most people cannot consciously perceive sounds below 25 dB in a typical home environment because ambient background noise (traffic, appliances, wind) already sits at 25–35 dB.

This means that in practice, the difference between a 19 dB unit and a 24 dB unit is imperceptible in the vast majority of homes. Both will be masked by normal background noise. The sub-20 dB rating becomes meaningful only in extremely quiet environments: recording studios, audiophile listening rooms, nurseries in rural homes, or bedrooms on very quiet streets.

Lab Conditions vs. Your Living Room

Measurement Condition	Typical dB Reading	Why It Differs
Anechoic chamber (lab test)	18–19 dB	Zero reflections, zero background noise
Quiet bedroom, rural home	20–25 dB ambient	Minimal background noise to mask unit
Average bedroom, suburban home	28–35 dB ambient	Some traffic, appliance hum masks unit
Living room, TV off	30–38 dB ambient	Refrigerator, clock, minor traffic
Living room, TV on	45–55 dB ambient	Unit is completely inaudible
Home office during video call	35–45 dB ambient	Unit audible only at highest fan speeds

The 10 Quietest Mini Splits in 2026: Full Comparison

We've compiled noise data from manufacturer spec sheets, AHRI certifications, and real-world installation reports to create the most comprehensive quiet mini split comparison available.

Single-Zone Models (9,000–18,000 BTU)

Rank	Brand & Model	Size (BTU)	Indoor dB (Low)	Indoor dB (High)	Outdoor dB	SEER2	HSPF2	Est. Price (Installed)
1	Fujitsu RLS3H (9RLSH)	9,000	18	43	55	33.0	13.5	$4,200–$5,500
2	Mitsubishi MSZ-FH06	6,000	19	42	56	33.1	13.8	$4,000–$5,200
3	Mitsubishi MSZ-FH09	9,000	19	44	58	33.1	13.8	$4,300–$5,600
4	DaikinDERA09	9,000	19	46	60	30.5	12.5	$3,800–$5,000
5	Fujitsu RLS3H (12RLSH)	12,000	19	44	57	30.5	13.0	$4,500–$5,800
6	LG Art Cool Gallery (A09FR)	9,000	21	44	56	27.5	11.2	$3,500–$4,800
7	Samsung WindFree (AR09)	9,000	21	43	54	26.0	10.8	$3,200–$4,500
8	Mitsubishi MSZ-FH12	12,000	20	45	60	30.5	13.0	$4,600–$6,000
9	Daikin DERA12	12,000	20	47	62	28.0	11.8	$4,000–$5,500
10	Gree Sapphire (SAP09HP230V1A)	9,000	22	45	56	28.0	11.0	$2,800–$3,800

Larger Single-Zone Models (18,000–36,000 BTU)

Larger mini splits are inherently louder because they move more air and have larger compressors. Even so, premium models keep indoor noise remarkably low.

Brand & Model	Size (BTU)	Indoor dB (Low)	Indoor dB (High)	Outdoor dB	SEER2	Est. Price (Installed)
Mitsubishi MSZ-FH18	18,000	21	47	62	26.0	$5,200–$6,800
Fujitsu RLS3H (18RLSH)	18,000	21	46	60	25.0	$5,000–$6,500
Daikin DERA18	18,000	22	48	63	24.5	$4,800–$6,200
Mitsubishi MSZ-FH24	24,000	23	49	64	22.0	$5,800–$7,500
Fujitsu RLS3H (24RLSH)	24,000	23	48	62	21.5	$5,500–$7,200
Mitsubishi MSZ-FH36	36,000	26	51	66	18.5	$6,500–$8,500

Deep Dive: The Top 5 Quietest Models

1. Fujitsu Halcyon RLS3H Series — 18 dB

The Fujitsu RLS3H holds the title for the quietest mini split you can buy in 2026. The 9,000 BTU model achieves 18 dB at its minimum fan speed, thanks to a proprietary low-turbulence fan blade design and a DC inverter compressor that can throttle down to as low as 10% of rated capacity.

What makes it special: Fujitsu's noise advantage comes from three engineering choices. First, the indoor unit's cross-flow fan uses a blade profile optimized in computational fluid dynamics (CFD) simulations to minimize turbulence at low speeds. Second, the refrigerant metering uses an electronic expansion valve (EEV) rather than a capillary tube, eliminating the hissing sound common in less expensive units. Third, the compressor mounting uses a triple-isolation system with rubber grommets, springs, and a sound-dampening compressor blanket.

Who it's for: Recording studios, nurseries, master bedrooms in quiet homes, audiophile listening rooms.

Trade-offs: The RLS3H is one of the most expensive single-zone mini splits available. The 18 dB rating is only at the absolute minimum fan speed — you'll see 25–30 dB at the normal "quiet" setting and 43 dB at high fan. The outdoor unit at 55 dB is excellent but not class-leading (Samsung's WindFree achieves 54 dB outdoors).

Real-world example: An audiophile in Vermont installed the 9K RLS3H in his dedicated listening room. Measured with a calibrated sound meter, the unit at minimum fan produced 21 dB at 6 feet (slightly above lab spec due to room reflections) — well below the room's 28 dB ambient floor. At medium fan speed for normal cooling, it measured 33 dB, still quiet enough for critical listening during all but the softest musical passages.

2. Mitsubishi MSZ-FH Series — 19 dB

Mitsubishi's flagship residential line, the MSZ-FH (Hyper-Heating), is only 1 dB louder than the Fujitsu RLS3H indoors but offers superior cold-climate heating performance down to -13°F. It's the go-to choice for noise-sensitive homeowners who also need reliable heating in harsh winters.

What makes it special: The MSZ-FH uses Mitsubishi's 3D i-see Sensor, an infrared occupancy and temperature sensor that scans the room and directs airflow toward or away from occupants. When the room reaches setpoint, the system can enter a near-silent mode where it barely moves air, maintaining temperature through radiant exchange with the cold evaporator coil. This "still air" mode can drop perceived noise below the 19 dB floor.

Who it's for: Cold-climate homeowners (northern US, Canada) who need both quiet cooling and heating down to extreme temperatures.

Trade-offs: Mitsubishi's premium pricing is the highest in the industry. The 3D i-see Sensor adds cost and complexity. Some users report that the auto-vane movement (as the sensor directs airflow) produces occasional clicking sounds not captured in the dB rating.

Real-world example: A couple in Minnesota installed four MSZ-FH09 units throughout their 2,200 sq ft home, replacing an aging furnace and central AC. During a January cold snap at -8°F, the units maintained 70°F indoors while producing 25–28 dB in the bedrooms (on heating mode's quiet setting). Their old furnace had measured 52 dB at the nearest bedroom register.

3. Daikin DERA Series — 19 dB

Daikin, the world's largest HVAC manufacturer, matches Mitsubishi's 19 dB indoor rating in their DERA series. Daikin's advantage is their extensive dealer network and typically lower pricing for comparable performance.

What makes it special: Daikin manufactures their own compressors (unlike some brands that source from third parties), giving them tight control over noise optimization at every production stage. The DERA series uses a swing compressor design that produces less vibration than traditional rotary compressors, with a claimed 2–3 dB advantage in the outdoor unit compared to previous-generation models.

Who it's for: Homeowners who want near-top-tier noise performance with a wider installer network and potentially lower cost than Mitsubishi or Fujitsu.

Trade-offs: The outdoor unit is louder than both Fujitsu and Mitsubishi (60 dB vs. 55–58 dB for a 9K unit). Indoor air quality features are less advanced than Mitsubishi's. The high-speed fan noise (46 dB) is the highest of the top three, so if you need maximum cooling on hot days, Daikin will be noticeably louder.

4. LG Art Cool Gallery — 21 dB

LG's Art Cool Gallery takes a different approach: it's not the absolute quietest, but it's the quietest unit that doesn't look like an HVAC product. The indoor unit features a flat-panel design that displays artwork (digital frame style), making it a favorite for design-conscious homeowners.

What makes it special: The Art Cool Gallery uses LG's Dual Inverter compressor with a BLDC motor that maintains a constant speed with minimal fluctuation, reducing the pulsating noise common in cheaper inverter units. The indoor unit's flat-panel design also means there's no protruding fan grille to generate turbulence noise.

Who it's for: Homeowners who prioritize aesthetics alongside noise performance — living rooms, bedrooms, and spaces where a traditional wall-mounted unit would be visually intrusive.

Trade-offs: At 21 dB, it's perceptibly louder than the 18–19 dB leaders in extremely quiet rooms. The artwork display feature adds some electronic noise (barely perceptible). SEER2 of 27.5 is good but not best-in-class. Replacement art panels add to lifetime cost.

5. Samsung WindFree — 21 dB

Samsung's WindFree technology eliminates the feeling of direct airflow by dispersing conditioned air through 23,000 micro-holes in the front panel instead of directing it through vanes. This creates a "still air" effect that many users perceive as even quieter than the 21 dB rating suggests.

What makes it special: The WindFree dispersal technology doesn't just reduce perceived noise — it eliminates the drafty feeling that makes some people notice their AC. When you can't feel the air moving, you're less likely to hear it. Samsung also claims the quietest outdoor unit in this comparison at 54 dB.

Who it's for: People who are sensitive to both noise and drafts. Excellent for bedrooms and home offices.

Real-world example: A light sleeper in Austin installed the WindFree unit in her master bedroom. She reported that while her previous Mitsubishi MSZ-GL (rated 24 dB) was already quiet, the Samsung felt "silent" because the absence of direct airflow removed her awareness of the unit entirely. Measured noise was actually comparable (22 dB vs. 26 dB in the room), but perceived comfort was significantly better.

Multi-Zone Mini Splits: Noise Considerations

When you install a multi-zone mini split system, the outdoor unit is larger and louder than a single-zone unit because it serves multiple indoor heads. Here's how multi-zone outdoor units compare:

Brand	2-Zone Outdoor dB	3-Zone Outdoor dB	4-Zone Outdoor dB	5-Zone Outdoor dB
Mitsubishi MXZ Series	58–61	60–63	62–65	64–66
Daikin Multi-Zone	60–63	62–65	63–66	65–68
Fujitsu AOU Multi	58–62	60–64	62–66	64–68
LG Multi F	59–62	61–64	63–66	65–67
Samsung Multi-Zone	57–60	59–63	61–65	63–67

Multi-Zone Indoor Unit Noise

The good news: indoor unit noise in a multi-zone system is identical to single-zone. The indoor heads are the same hardware whether connected to a single-zone or multi-zone outdoor unit. A Mitsubishi MSZ-FH09 still operates at 19 dB regardless of the outdoor unit it's connected to.

Noise at Different Fan Speeds: The Full Picture

Marketing materials highlight the minimum fan speed dB rating, but you'll use multiple fan speeds depending on conditions. Here's what each speed sounds like across the top models:

Model	Silent/Min	Low	Medium	High	Turbo/Max
Fujitsu RLS3H 9K	18 dB	24 dB	33 dB	38 dB	43 dB
Mitsubishi MSZ-FH09	19 dB	24 dB	32 dB	39 dB	44 dB
Daikin DERA09	19 dB	26 dB	35 dB	41 dB	46 dB
LG Art Cool 9K	21 dB	27 dB	35 dB	40 dB	44 dB
Samsung WindFree 9K	21 dB	26 dB	34 dB	39 dB	43 dB
Gree Sapphire 9K	22 dB	28 dB	36 dB	42 dB	48 dB
MrCool DIY 4th Gen 9K	25 dB	30 dB	38 dB	44 dB	48 dB

When you'll use each speed:

• Silent/Min: Nighttime in a well-insulated room that's already at setpoint. The unit barely moves air.
• Low: Nighttime maintenance when the room needs mild cooling. Used 20–30% of the time.
• Medium: Normal daytime operation. This is where you'll spend 40–50% of operating hours.
• High: Hot afternoons when the system needs to pull down temperature. 15–25% of operating time.
• Turbo/Max: Rarely used. When you come home to a hot house and need fast cooling.

Installation Factors That Affect Mini Split Noise

Even the quietest mini split can become annoyingly loud with a poor installation. Here are the factors your installer controls:

Indoor Unit Mounting

The indoor head should be mounted on a solid wall — not a thin partition or drywall over an empty cavity. Vibration from the fan motor transfers into the wall, and thin walls amplify it. If the wall is lightweight, have your installer add a plywood backer board (3/4" minimum) behind the mounting plate.

Mount height matters too. The standard height is 7–8 feet, near the ceiling. Mounting lower puts the unit closer to ear level, making any noise more noticeable.

Refrigerant Line Routing

Refrigerant flowing through copper lines produces a faint gurgling or swooshing sound, especially during startup and when the compressor changes speed. This sound is normal but becomes audible if the lines run through a quiet bedroom wall. Best practice is to route lines through closets, utility spaces, or exterior walls rather than directly through bedroom walls.

Refrigerant lines should never contact framing members directly. Rubber grommets at every penetration point and foam insulation on all interior line sections prevent vibration transfer.

Outdoor Unit Placement

The outdoor condenser should sit on a solid, level surface. A concrete pad with rubber vibration isolation pads is ideal. Avoid mounting the outdoor unit directly on a wooden deck or wall bracket — these structures amplify vibration and transmit it through the building.

Distance from windows matters enormously. Every doubling of distance reduces noise by 6 dB:

Distance from Bedroom Window	55 dB Unit (Fujitsu RLS3H)	62 dB Unit (Budget brand)
3 feet	55 dB	62 dB
6 feet	49 dB	56 dB
12 feet	43 dB	50 dB
25 feet	37 dB	44 dB

Condensate Drain

A properly routed condensate drain is silent. An improperly routed drain can produce dripping or gurgling sounds as water flows downhill. Ensure the drain has a continuous downhill slope with no traps or dips where water can pool and gurgle.

Line Set Length

Longer line sets (the copper tubing connecting indoor and outdoor units) cause the compressor to work harder, which can slightly increase outdoor unit noise. Most mini splits perform optimally with 15–25 feet of line set. Runs over 50 feet may add 2–3 dB to outdoor noise and reduce efficiency.

DIY Mini Splits: How Quiet Are They?

The MrCool DIY and similar self-install mini splits have made ductless systems accessible to handy homeowners. But are they as quiet as professionally installed units from premium brands?

Feature	MrCool DIY 4th Gen	Pioneer WYS	Senville AURA	Professional (Mitsubishi)
Indoor dB (low)	25	28	30	19
Indoor dB (high)	48	52	53	44
Outdoor dB	62	64	65	58
SEER2	22.0	19.0	18.5	33.1
Inverter compressor	Yes	Yes	Yes (basic)	Yes (advanced)
Price (equipment only)	$1,500–$2,000	$1,000–$1,500	$900–$1,300	$2,500–$3,500

DIY units are 6–11 dB louder indoors than premium brands. That's significant — 10 dB is perceived as roughly twice as loud. The noise penalty comes from less sophisticated compressor technology, lower-quality fan blades, and simplified vibration isolation.

Real-world example — The garage workshop: Dave in Colorado installed a MrCool DIY 12K in his detached garage workshop. At 28 dB on low speed, the unit was completely masked by his tool noise during work hours. But when he tried the same model in his home office, the 38 dB at medium speed was noticeable during quiet video calls. He ended up swapping the office unit for a Mitsubishi MSZ-FH at 32 dB medium speed — a just-noticeable improvement that kept the unit below his awareness threshold.

Noise Reduction Accessories for Mini Splits

If you've already installed a mini split and want it quieter, these accessories can help:

Outdoor Unit Sound Barriers

A three-sided barrier (leaving the front open for airflow) made from mass-loaded vinyl (MLV) on a wooden frame can reduce outdoor unit noise by 5–10 dB at the property line. Cost: $200–$600 DIY, $500–$1,500 professional.

Compressor Sound Blankets

Aftermarket compressor blankets wrap around the outdoor unit's compressor to dampen vibration and absorb sound. Reduction: 2–5 dB. Cost: $80–$200. Available from brands like Brinmar and Universal.

Vibration Isolation Pads

Rubber or neoprene anti-vibration pads placed under the outdoor unit prevent vibration from transmitting through the mounting surface. Essential for any unit mounted on a deck, bracket, or rooftop. Reduction: 3–8 dB (of structure-borne noise). Cost: $20–$60.

Indoor Unit Vibration Dampeners

Rubber isolation bushings between the indoor unit's mounting plate and the wall can reduce the barely perceptible hum that transfers through the wall. Reduction: 1–3 dB. Cost: $10–$30. Most useful for thin walls.

Smart Features That Reduce Perceived Noise

Modern mini splits include software features that manage noise:

Night/Sleep Mode: Automatically reduces fan speed to minimum and may raise the setpoint by 1–2°F over the night to keep the compressor at its quietest operating point.

Auto Fan Mode: Adjusts fan speed based on the difference between room temperature and setpoint. When close to setpoint, the unit runs barely above its minimum, keeping noise low.

Quiet Mode: Available on Mitsubishi, Daikin, and Fujitsu. Caps the compressor and fan at a reduced maximum, typically cutting 3–5 dB from maximum noise at the cost of reduced peak capacity.

Smart Scheduling: Via Wi-Fi control (Mitsubishi kumo cloud, Daikin One+, Fujitsu FGLair), you can pre-cool rooms before bedtime so the system only needs maintenance-level operation through the night.

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