LG KUSXB121A Single Zone Mini Split Outdoor Condenser Unit with 12000 BTU Cooling Capacity, 14000 BTU Heating Capacity and Gold Fin Protection in White

LG's devotion to providing efficient ductless solutions can be seen across their entire catalog. The KUSXB121A is a single zone mini split outdoor condenser capable of supplying ductless heating and cooling to any room in your home. With inverter technology and quiet operation this well-rounded mini split outdoor condenser is an easy choice for any system.

• Gold Fin Condenser
• Inverter Technology

Enhanced Connectivity

LG's new R-32 mini split units require a 5-conductor cable (Not Included) instead of the standard 4-conductor, improving communication reliability and enabling a new leak detection feature.

Low Ambient Operations

This outdoor unit supports cooling operations down to 5 degrees Fahrenheit and heating operations down to -4 degrees Fahrenheit. There is also a defrost feature, which removes frost from the condenser coil in frigid conditions.

Quiet Design

Thanks to a brushless direct current motor and a twin rotary compressor, the unit is significantly quieter than traditional air conditioning systems. These components reduce mechanical sound, electrical sound, and vibrations within the unit.

*Note: Indoor Unit Required to Operate

Matching Products

• Matching Air Handler Indoor Unit KNSLB121A
• Matching 4-Way Cassette Indoor Unit KNUDB121A
• Matching Mid Static Duct Indoor Unit KNUJB121A
• Matching Wall Console Indoor Unit KNUQB121A

Why Buy LG KUSXB121A Single Zone Mini Split Outdoor Condenser Unit

• Energy Efficiency: The unit’s variable-speed inverter compressor adapts its output to match your heating and cooling needs, avoiding constant start-stop cycles. This results in lower energy use and reduced utility bills over time.
• Quiet Operation: Equipped with a brushless direct current motor and a twin rotary compressor, the system minimizes noise, mechanical vibration, and sound—making it well-suited for quiet spaces like bedrooms, patios, or home offices.
• Corrosion Resistance: LG’s Gold Fin coating protects the condenser coil from environmental damage caused by pollutants, salt, and moisture, enhancing the unit’s durability and extending its service life.
• Reliable All-Season Performance: Designed for year-round comfort, the system operates in cooling mode down to 5°F and in heating mode down to -4°F. A built-in defrost function prevents ice buildup on the coil during cold conditions.
• Enhanced Connectivity: Using a 5-conductor communication cable with LG’s R-32 refrigerant units ensures more reliable communication between indoor and outdoor components, while enabling a new refrigerant leak detection feature for added protection.

• Dependable Warranty: LG backs its mini split systems with a 10-year warranty, provided the unit is installed by a licensed contractor and registered within the required timeframe.

Frequently Asked Questions

Q: What kind of unit is the LG KUSXB121A?

A: The LG KUSXB121A is a 12,000 BTU single-zone outdoor condenser designed for ductless mini-split heat pump systems. It operates with a compatible LG indoor unit to provide heating and cooling.

Q: What are the main features of the KUSXB121A?

A: Key features include:

• Inverter technology with a variable-speed compressor for improved energy efficiency.
• Quiet operation, thanks to a brushless DC motor and twin rotary compressor.
• Gold Fin anti-corrosion coating on the heat exchanger for enhanced durability.
• Environmentally friendly R-32 refrigerant.
• Low-temperature operation: down to 5°F for cooling and -4°F for heating.
• Defrost mode to prevent frost build-up on coils.
• Electronic expansion valve for precise refrigerant control.

Q: What is the Gold Fin coating, and how does it help?

A: Gold Fin is an anti-corrosion coating applied to the heat exchanger. It protects the unit from rust and corrosion, extending its lifespan—especially in coastal or humid climates.

Q: What accessories are needed for installation?

A: The following field-supplied components are typically required:

• Refrigerant lineset to connect indoor and outdoor units
• Drain tubing for condensate removal
• Disconnect box and electrical whip kit
• 14 AWG 5-conductor stranded communication wire
• Outdoor condenser pad or wall bracket to elevate the unit off the ground

Q: Why is my unit showing an "88" error?

A: The "88" error indicates a communication fault between the indoor and outdoor units. Common causes include:

• Loose or incorrect wiring at the CN105 connector
• Damaged or incorrect communication cable
• Faulty outdoor fan motor or capacitor

Q: What does the "CH 61" error code mean?

A: "CH 61" appears when the outdoor heat exchanger overheats. Likely causes:

• Poor ventilation due to installation in enclosed areas like balconies
• Obstructions around the outdoor unit blocking airflow

Q: My unit is making unusual sounds. What could be wrong?

A: While some operational noise is normal, unusual sounds could indicate issues with:

• The brushless DC motor
• The twin rotary compressor
• LG provides sound recordings on its support website to help diagnose the issue.

Q: How can I confirm that the communication wiring is correct?

A: For R-32 models like the KUSXB121A:

• Use a 5-conductor stranded communication cable
• Verify tight and accurate wiring connections
• Refer to the LG installation manual and local electrical codes for full compliance

Q: What should I check if the unit’s heating or cooling performance is poor?

A: Check the following:

• Proper refrigerant line length and elevation
• Compatibility with the paired LG indoor unit

• If issues persist, an HVAC technician should inspect for system-specific faults.

Pros

• Good mid-size capacity: suits medium rooms well without being oversized.
• High efficiency ratings: SEER2 ~ 19.7, EER2 ~ 13, HSPF2 ~ 10.5, which means lower energy use especially in moderate climates.
• Cold-climate capable: maintains heating at relatively low outdoor temperatures.
• Corrosion resistance: Gold Fin protection helps the outdoor coil last longer, especially in humid or corrosive environments.
• R-32 refrigerant: more environmentally friendly than older refrigerants.
• Flexible installation: reasonable line set piping limits (~65.6 ft) allow some flexibility in placement.
• ENERGYSTAR certified: meets recognized standards for efficiency.

Cons

• Noise: outdoor unit noise (~ 50-56 dB) is moderate — not very loud but not extremely quiet either. Could be heard in quiet surroundings.
• Performance drop in very cold climates: while it performs reasonably well when cold, heating capacity will fall when outside temps drop far below rated minimums.
• Cost of full system: this is just the outdoor condenser; you’ll need indoor unit(s), piping, installation etc., which add to overall cost.
• Electrical requirements: requires proper power supply (208-230 V), breakering, wiring etc—needs professional installation.

Conclusion

The LG KUSXB121A is a solid option if you're looking for a moderately powerful and efficient outdoor condenser for a small-to-medium room. It balances good heating/cooling ability, high efficiency, and durability (via Gold Fin) in a package that should give reliable performance in many climates.