LG KUSXA421A LGRED Single Zone Mini Split Outdoor Condenser Unit with 42000 BTU Cooling Capacity, 48000 BTU Heating Capacity and Gold Fin Protection in White

LG continues to demonstrate global leadership in innovation and technology with their advancements in home comfort solutions. The LGRED° Heat ductless heat pump system boasts superior heating performance in extreme cold weather climates. The KUSXA421A 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 -13 degrees Fahrenheit. There is also a defrost feature, which removes frost from the condenser coil in frigid conditions.

Integrated Base Pan Heater

Base pan heaters come factory installed on all LGRED° outdoor condensers in order to mitigate the risk of damage caused by freezing condensate.

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 4-Way Cassette Indoor Unit KNSCB421A

• Matching Mid Static Duct Indoor Unit KNSJB421A

Why Buy LG KUSXA421A LGRED Single Zone Mini Split Outdoor Condenser Unit

• LGRED° Heat Technology: Engineered for superior cold-climate performance, this system delivers strong, reliable heating even in extreme winter conditions.
• Low Ambient Heating: Capable of maintaining warmth in freezing temperatures, the unit operates efficiently in outdoor conditions as low as -13°F.
• Built-In Base Pan Heater: A factory-installed base pan heater prevents condensate from freezing within the unit, protecting against cold-weather damage and ensuring consistent operation.
• Inverter Technology: Featuring a variable-speed compressor and electronic expansion valve, the system precisely controls refrigerant flow to reduce energy use and maintain stable indoor temperatures.
• Quiet Design: With a brushless direct current motor and twin rotary compressor, the unit minimizes operational noise, running as quietly as 52 dB—ideal for residential comfort.
• Gold Fin Protection: The heat exchanger is coated with LG’s anti-corrosive Gold Fin finish, enhancing durability by resisting damage from moisture, salt, and pollutants.
• Improved Communication: The unit utilizes a 5-conductor communication cable (sold separately) for greater system reliability and includes a built-in refrigerant leak detection feature.
• Trusted Certifications: This model is Energy Star listed, CSA-listed, and AHRI certified—assuring that it meets rigorous standards for energy efficiency, safety, and performance.

Frequently Asked Questions

Q: What are the operating temperature ranges?

A: The unit operates in:

• Cooling Mode: Operates between 5°F and 118°F
• Heating Mode: Operates between -13°F and 64°F

Q: What are the key features of the LGRED Single Zone Mini Split Outdoor Condenser Unit?

A: Notable features include:

• High efficiency with inverter technology, a variable-speed compressor, and an electronic expansion valve for precise refrigerant control.
• Quiet operation, using a brushless DC motor and twin rotary compressor to reduce sound and vibration.
• Enhanced durability via a corrosion-resistant Gold Fin™ coating on the heat exchanger.
• Cold climate readiness, including a factory-installed base pan heater to prevent freezing and damage.
• Smart connectivity, requiring a 5-conductor cable for stable communication with the indoor unit and featuring built-in leak detection.

Q: What accessories are required for installation?

A: The following components are typically needed:

• Line set: Double-insulated tubing for refrigerant flow
• Drain tubing: For removing condensate
• Disconnect box and whip kit: For electrical connection to your home’s fuse box
• Connecting wire: To deliver power and signals from the condenser to the indoor unit
• Outdoor condenser pad or wall bracket: To keep the unit off the ground and ensure stable mounting

Q: What are the electrical requirements for this unit?

A: Electrical requirements are:

• Voltage: 208–230V
• Phase: Single-phase
• Frequency: 60Hz
• Wiring for Outdoor Unit (ODU): 3 x 12 AWG cable required

Q: How does inverter technology improve performance?

A: Inverter technology uses a variable-speed compressor to continuously adjust refrigerant flow, maintaining consistent temperatures and eliminating energy-wasting on/off cycles. This provides better comfort and energy efficiency than traditional systems.

Q: What is the purpose of the Gold Fin protection?

A: The Gold Fin coating on the heat exchanger prevents corrosion, extending the lifespan of the unit—especially beneficial in coastal or high-humidity environments.

Q: How does the base pan heater function in cold climates?

A: The factory-installed base pan heater prevents water from freezing in the drain pan. This helps protect the unit and ensures reliable operation in sub-freezing temperatures.

Pros

1. High Performance in Both Heating & Cooling
   The unit provides strong capacity for large spaces or high load, and works across a wide temperature range including cold outdoor conditions.
2. Low-Ambient Capability
   Able to operate even when it’s cold outside (down to −13°F for heating), which is great if you live in a place with cold winters.
3. Durability Features
   Gold Fin coating helps resist corrosion, especially useful in humid, coastal or salty environments. The base pan heater helps prevent freezing issues.
4. Long Piping Flexibility
   The ability to run up to ~246 ft between indoor and outdoor units gives flexibility in system layout and installation.
5. Modern Inverter Technology
   Variable speed compressor, electronic expansion valve, helps with energy efficiency, smoother operation, and reduces extremes in startup current.
6. Energy Star Certified
   Helps reduce running cost (efficient operation), especially when you use both heating and cooling often.

Cons

1. Sound Level
   56 dB is reasonable for its capacity, but it’s still audible. For placement near bedrooms or quiet outdoor spaces, this could be noticeable.
2. High Initial Cost & Installation Complexity
   As a large-capacity outdoor unit, costs for both equipment and professional installation can be significant. Also, need proper electrical infrastructure (breaker, wiring etc).
3. Performance Drop in Extreme Weather
   Although it’s rated for low ambient heating, as with most heat pumps, capacity will drop as outdoor temperature goes well below the rated minimum.
4. Requires Matching Indoor Equipment & Accessories
   The condenser is just one part of the system; you’ll need compatible indoor unit(s), line sets, remote control wiring, condensate drainage etc, which adds to overall cost.
5. Size & Weight
   It’s heavy and large; mounting or pad placement must be stable; logistics for delivery, handling etc become more challenging.

Conclusion

The LG KUSXA421A is a solid choice if you need a powerful, reliable outdoor condenser for a ductless system in a large space, especially if you live in an area with cold winters. Its strengths lie in its capacity, durability (Gold Fin, base pan heater), efficient inverter tech, and long piping flexibility.