Description
Overview
This bundled LG Multi F Max system pairs one KUMXB481A R32 outdoor unit with four wall-mounted indoor zones to deliver multi-room comfort from a single refrigerant circuit. The outdoor unit is rated at 48,000 Btu/h cooling and 54,000 Btu/h heating, with modulation ranges of 10,800~48,000~58,000 Btu/h cooling and 12,420~54,000~59,000 Btu/h heating. Included indoor equipment is 1 KNUAB091A wall-mounted indoor unit (9,000 Btu/h cooling, 10,900 Btu/h heating); 3 KNUAB121A wall-mounted indoor units (12,000 Btu/h cooling, 13,600 Btu/h heating), allowing a combined nominal indoor total of 45,000 Btu/h cooling and 51,700 Btu/h heating across four zones. Each indoor unit is wall mounted and uses a cross-flow fan to deliver conditioned air directly into the occupied space with selectable fan speeds. The refrigerant used is R32 and both the outdoor and indoor sections use electronic expansion valve (EEV) control for metered refrigerant delivery to connected zones. Refrigerant piping is supported up to 475.7 ft total, with 32.8 / 229.6 ft minimum/maximum outdoor-to-indoor segment limits for system layout flexibility.
Performance
Capacity control is driven by a variable-speed scroll compressor in the outdoor unit, coordinating with EEV metering to match load across multiple indoor calls. Cooling operation is specified from 14 to 118°F DB outdoor ambient, supporting hot-weather performance where condenser operating range matters. Heating operation is specified from -4 to +64°F WB outdoor ambient, helping maintain output in cold conditions with defrost and deicing logic. Outdoor airflow is provided by two propeller fans with a maximum airflow rate of 2,295 x 2 CFM, supporting heat exchanger heat transfer under varying loads. Indoor air delivery varies by zone and model to balance throw, mixing, and noise, and each zone includes dehumidification capacity listed in the unit data for moisture control. Included indoor units provide the following zone airflow and sound data: 1× KNUAB091A delivers 268 / 218 / 169 CFM (H/M/L) with sound pressure 36 / 32 / 27 dB(A) (H/M/L); 3× KNUAB121A delivers 282 / 233 / 177 CFM (H/M/L) with sound pressure 38 / 34 / 29 dB(A) (H/M/L).
Smart Features
Zone control is supported through on-board indoor control functions such as auto operation, auto restart, and group control for coordinated operation when needed. Each indoor unit includes built-in Wi‑Fi via the Smart ThinQ app and ships with a wireless remote controller, enabling room-by-room setpoint and mode control. Controller options listed for the indoor units include MultiSITE CRC controllers, simple remote controllers, Standard III remote controllers, and a deluxe remote controller for job-specific control strategies. The outdoor unit includes an integrated central control connection and supports monitoring and control accessories, which can help standardize operation across multi-zone installations. A 24-hour on/off timer and sleep mode are included at the indoor level, providing scheduling and setback capability without requiring third-party controls. For multi-zone refrigerant distribution, the outdoor platform is designed to work with compatible branch distribution hardware so the system can route capacity to multiple connected indoor circuits.
Comfort & Noise
Sound pressure for the outdoor unit is listed at 53 / 55 dB(A) for cooling/heating, supporting placement decisions where equipment noise is a consideration. Indoor sound pressure varies by model and fan speed, with listed ranges of 26–38 dB(A) across the included wall-mounted units depending on the selected speed. Each indoor unit supports left/right and up/down auto swing to distribute airflow across the zone and reduce temperature stratification near the unit. Jet cool and jet heat modes provide rapid ramp behavior when a space needs a quick pull-down or warm-up, then the system returns to modulated operation for steady control. A 3M Micro Dust secondary filter and a washable pre-filter are included to support particulate capture and serviceable filtration at the indoor unit. Self-cleaning indoor coil logic is included to help manage moisture on the coil surface and support consistent airflow and heat transfer over time.
Use Case Fit
This configuration is well suited for residential, multi-family, and light commercial applications where four independent rooms or zones need separate temperature control. A multi-zone architecture reduces the need for multiple outdoor units while still providing individual indoor fan and setpoint control by zone. Piping limitations allow long runs up to 475.7 ft total and vertical separation up to 98.4 ft between outdoor and indoor units, supporting multi-story layouts when designed within limits. Wall-mounted indoor units are a fit where ductwork is not desired and where direct air delivery is preferred for fast response and simplified zoning. The outdoor unit supports a minimum of 2 and up to 8 connected indoor units on the platform, leaving headroom for alternate system designs beyond this four-zone bundle. Operating range coverage supports a wide set of regional conditions, including hot summer ambient cooling and subfreezing outdoor heating operation.
Value & Reliability
The outdoor heat exchanger uses Gold Fin™ coating, supporting coil durability in typical outdoor exposure conditions. Self diagnosis, auto restart, and restart delay functions are included on the outdoor unit to support stable system recovery after power interruption and to aid troubleshooting. Defrost and deicing functions are included to manage frost accumulation during heating operation, supporting heat transfer and airflow at lower ambient conditions. Refrigerant charge is listed at 7.5 lbs and additional refrigerant charge rates are provided for extended piping, supporting accurate charging in longer-run applications. Indoor units include an R32 leak detection sensor and thermistor-based temperature sensing, supporting refrigerant safety monitoring and responsive control. Brushless digitally controlled indoor fan drive and inverter (variable-speed fan) logic support staged airflow selection and quiet operation across typical loads.
Summary Wrap-Up
For buyers who need a single-system solution for four rooms, this bundle combines a high-capacity outdoor heat pump with matched wall-mounted indoor delivery units. The outdoor unit provides broad modulation and supports refrigerant distribution to multiple indoor circuits while keeping electrical requirements at 208–230V single phase. Included indoor units provide per-room airflow and control features, including Wi‑Fi control, auto swing, and serviceable filtration, to support day-to-day comfort management. System limits for piping length and elevation allow flexible layouts, which can reduce routing constraints in retrofit and new construction applications. With coordinated compressor modulation and zone-level fan control, the architecture supports stable space temperatures while avoiding the all-or-nothing cycling behavior of single-speed systems. This configuration is a practical option for D2C and wholesale customers seeking a four-zone LG Multi F Max platform with matched capacities and documented operating ranges.
Key Features
- Variable-speed scroll compressor: Delivers 10,800~48,000~58,000 Btu/h cooling and 12,420~54,000~59,000 Btu/h heating modulation to match multi-zone demand.
- R32 refrigerant circuit with EEV control: Uses R32 refrigerant and electronic expansion valve metering in both outdoor and indoor sections for controlled refrigerant delivery.
- Four wall-mounted indoor zones: Includes 1 KNUAB091A wall-mounted indoor unit (9,000 Btu/h cooling, 10,900 Btu/h heating); 3 KNUAB121A wall-mounted indoor units (12,000 Btu/h cooling, 13,600 Btu/h heating) to provide four independent air delivery points with cross-flow fans and selectable fan speeds.
- Built-in Wi‑Fi and wireless remote control: Indoor units include built-in Wi‑Fi via the Smart ThinQ app and ship with wireless remote controller AKB76044208 for zone-level operation.
- Documented operating ranges: Supports cooling operation from 14 to 118°F DB and heating operation from -4 to +64°F WB for seasonal performance coverage.
- Refrigerant piping allowances: Supports up to 475.7 ft total piping with 32.8 / 229.6 ft outdoor-to-indoor segment limits and up to 98.4 ft outdoor-to-indoor elevation.
- Coil coating and diagnostic functions: Gold Fin™ outdoor coil coating plus self diagnosis, defrost/deicing, and auto restart functions support serviceability and seasonal operation.
