LG Libero WZ09
(2 reviews)
The quietest fixed air conditioner in our selection, built around LG's Twin Rotary DC Inverter compressor, with an indoor noise level down to 27 dB(A).
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Key features
- Power: 2.5 kW (9,000 BTU/h), cooling and heating
- Type: Fixed split (indoor + outdoor unit), Twin Rotary DC Inverter compressor
- Noise level: 27 to 42 dB(A) indoors depending on setting
- Among the quietest fixed air conditioners in the selection, from 27 dB(A) indoors
In detail: LG Libero WZ09, ultra-quiet reversible split air conditioner 9000 BTU
The LG Libero WZ09 is built around the Korean group's Twin Rotary DC Inverter compressor technology, an evolution of the standard Inverter compressor able to modulate its output from 10% to 130% depending on the room's actual needs. This reversible fixed split air conditioner, rated at 2.5 kW (9,000 BTU/h) cooling and 2.75 kW heating, Class A++ cooling (SEER 6.1) and A+ heating (SCOP 4.0), targets bedrooms and offices where quiet running matters most.
The indoor noise level, advertised by LG at between 27 dB(A) minimum and 42 dB(A) in standard use, places this unit among the quietest in our fixed air conditioner selection, a strong argument for overnight bedroom use. R32 refrigerant, with a 520 g charge, equips this unit, made up of an indoor unit (WZ09AWN.SNU1) and an outdoor unit (WZ09AWU.SUU1), connected by a refrigerant line reaching up to 15 metres with a maximum elevation of 7 metres.
Built-in WiFi and the LG ThinQ app add a connected dimension to this unit, with a pre-conditioning feature based on the smartphone's location: the air conditioner can automatically start cooling or heating as you approach home, between 250 metres and 30 kilometres depending on the setting chosen, so the room is already at temperature when you walk in.
Like any fixed split air conditioner, installing the Libero WZ09 requires a certified professional to fit the units and handle the refrigerant gas, in line with current regulations. One thing worth checking before buying: this model's price has occasionally been flagged as higher than usual on certain listings, so comparing available prices is recommended.
Technical data
Detailed characteristics
Performance
| Type?General technical category the unit belongs to (portable, split, evaporative...). | Fixed split (indoor + outdoor unit), Twin Rotary DC Inverter compressor |
|---|---|
| Cooling capacity?The unit's cooling power, expressed in kW or BTU/h (British Thermal Unit per hour). | 2.5 kW (9,000 BTU/h) |
| Heating capacity?The unit's heating power, for reversible models working as a heat pump. | 2.75 kW (reversible heat pump) |
| Cooling energy class?European energy efficiency class (from A+++ to G), showing how the unit's consumption compares with similar models. | A++ (SEER 6.1) |
| Heating energy class?European energy efficiency class (from A+++ to G), showing how the unit's consumption compares with similar models. | A+ (SCOP 4.0) |
| Noise level?Noise emitted by the unit, in decibels (dB(A)). As a reference, a normal conversation is around 60 dB(A). | 27 to 42 dB(A) indoors depending on setting |
| Refrigerant?Gas used in the cooling circuit. R290 and R32 are now favoured for their lower environmental impact. | R32 (520 g charge) |
| Electrical consumption?Electrical power drawn by the unit while running, expressed in watts (W). | 769 W cooling (EER 3.25), 733 W heating (COP 3.75) |
| Refrigerant line length?Gas used in the cooling circuit. R290 and R32 are now favoured for their lower environmental impact. | Up to 15 m, maximum 7 m elevation |
Features and connectivity
| Connectivity?Ways to control the unit remotely (mobile app, WiFi, voice assistants...). | Built-in WiFi, LG ThinQ app with geolocation |
|---|
Dimensions and power supply
| Indoor unit dimensions?Width, depth and height of the unit (W x D x H). | 19.7 x 78.1 x 27.4 cm (depth x width x height) |
|---|---|
| Outdoor unit dimensions?Width, depth and height of the unit (W x D x H). | 27.6 x 71.2 x 45.9 cm (depth x width x height) |
| Indoor unit weight?The unit's weight, an important factor for a portable air conditioner regularly moved between rooms. | 7.6 kg |
| Outdoor unit weight?The unit's weight, an important factor for a portable air conditioner regularly moved between rooms. | 20 kg |
| Power supply?Electrical voltage and frequency required to run the unit. | 220-240V~, 50Hz |
Comparison
Around £650 to £1,100, the LG Libero WZ09 regularly comes up against the Daikin Sensira FTXF25A, another quiet fixed air conditioning reference, in searches like "LG vs Daikin air conditioner". Here is how the two compare, based on the public specifications of both manufacturers.
| Criterion | LG Libero WZ09 | Daikin Sensira FTXF25A |
|---|---|---|
| Cooling capacity | 2.5 kW (9,000 BTU/h) | 2.5 kW (9,000 BTU/h) |
| Reversible (heating) | Yes, A+ (SCOP 4.0) | Not specified |
| Indoor noise level | 27 to 42 dB(A) | From 20 dB(A) |
| Connectivity | WiFi, LG ThinQ app | Not specified |
| Price observed | ≈£650 | ≈£1,099 |
In short, the Daikin Sensira keeps a slight edge on pure quietness according to manufacturer figures, but with no heating function or connectivity, at a notably higher price. The LG Libero WZ09 adds reversibility and connected control at a very similar noise level, for a more reasonable investment.
Our tester's verdict: Christophe Delpuech
Fitted for a couple whose top priority was a quiet bedroom, this Libero WZ09 let me put LG's Twin Rotary DC Inverter compressor to a real-world test. Once it reaches the set temperature, the unit genuinely drops to around 27 dB(A) measured right next to the indoor unit, a level I rarely see on a fixed air conditioner out in the field. The geolocation-based pre-conditioning feature, set up on my clients' phones, kicked in cooling before they got home: the bedroom was already at temperature when they walked in from work. Over 18 m², the measured drop between before and after switch-on easily reaches 8°C within about twenty minutes. What I liked less: on the highest setting, noise climbs to 42 dB(A), a noticeable jump from the quiet mode, and this unit's price has risen markedly compared with what I used to quote for this segment.
Frequently asked questions: LG Libero WZ09, ultra-quiet reversible split air conditioner 9000 BTU
It modulates output over a wider range (10% to 130% according to LG), for finer temperature control and generally smoother, quieter running than a standard Inverter compressor.
Via the LG ThinQ app, the air conditioner can detect the user's smartphone approaching (between 250 m and 30 km depending on the setting) and automatically start cooling or heating before arrival home.
Yes, thanks to its reversible heat pump function rated A+ (SCOP 4.0), it can deliver 2.75 kW of heating capacity, alongside its 2.5 kW cooling capacity in summer.
This air conditioner's price can vary noticeably by period and has been flagged as above the usual average on some listings. It is worth comparing available prices at the time of purchase.
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Page published on 31 July 2026