LG KNSJB421A Mid Static Duct Indoor Unit with 42000 BTU Cooling Capacity, 48000 BTU Heating Capacity and Washable Filter in Silver

LG's devotion to providing efficient ductless solutions can be seen across their entire catalog. The mini split indoor unit is designed for installation in short-run ducting with mid static pressures. Concealed duct indoor units mean that you can add mini split zones with no visible indoor units. With the mid static ducted unit, a small air register is the only clue that a mini split is providing effective heating and cooling to your space.

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.

Quiet Design

The unit can operate at volumes as low as 36 dB thanks to its advanced fan motor. The brushless direct current motor reduces electrical and mechanical sound while providing powerful air movement.

Automated Operation

Auto operation mode continually compares your zone's current and desired temperatures and uses that data to intelligently adjust the unit's fan speed and refrigerant flow to provide optimal comfort.

Sleep Mode

With the Sleep Mode and Timer functions, you can set this indoor unit to save energy at night. Sleep Mode will incrementally adjust temperature for an hour before the Timer function automatically deactivates the unit.

Condensate Protection

Condensate overflow can damage your indoor unit and your home. An internal condensate pump with 27.5" of lift protects the unit through reliable, effective condensate removal.

Dehumidify

LG's indoor units include a dehumidifying operation mode. In this mode, the unit's internal sensors monitor temperature and modify the set point and fan speed to remove moisture from the air.

Improved Air Quality

The unit features an anti-fungal filter to keep your air clean. This filter captures contaminants like dust and bacteria, and it is washable to ensure long term air quality.

Hot-Start

When the Hot-Start function is enabled, the unit's fan will not engage until the outdoor condenser has had the opportunity to warm the indoor coil. This prevents the unit from blowing cold air during heating operations.

*Note: Outdoor Unit Required to Operate

Matching Products

• Matching Outdoor Unit KUSXB421A

• Matching LGRED Outdoor Unit KUSXA421A

Why Buy LG KNSJB421A Mid Static Ducted Indoor Unit

• Aesthetics and Design: As a concealed duct unit, this system delivers heating and cooling through subtle air registers, preserving clean interior lines without bulky or wall-mounted components. It's a perfect fit for minimalist aesthetics or custom-designed spaces.
• Quiet Performance: Equipped with a brushless direct current (BLDC) fan motor and cross-flow fan design, the unit operates at noise levels as low as 36 dB—quieter than most central air systems and comparable to a soft whisper—making it ideal for bedrooms, offices, and living areas.
• High Efficiency: Featuring LG’s inverter technology and a variable-speed compressor, the unit delivers precise temperature control while minimizing energy use. It avoids the inefficiency of frequent cycling and boasts a 18.3 SEER2 and 9.0 HSPF2, earning Energy Star certification for superior energy performance.
• Improved Air Quality: The unit is equipped with a washable anti-fungal filter designed to capture dust, bacteria, and other airborne particles, helping maintain clean, healthy indoor air over time.

• Reliable Protection: An integrated condensate pump with a 27.5" lift ensures effective moisture removal, safeguarding the unit and surrounding space from potential condensate overflow damage.

Frequently Asked Questions

Q: What is the LG KNSJB421A?

A: The LG KNUJB361A is an indoor ducted heat pump designed for multi-zone systems. It provides both heating and cooling functions.

Q: Is the LG KNSJB421A Energy Star certified?

A: Yes, this unit is Energy Star rated for energy efficiency.

Q: Can the KNSJB421A be used for both heating and cooling?

A: Yes, it is a convertible model that offers both heating and cooling capabilities.

Q: What is the "Hot-Start" feature and how does it work?

A: The "Hot-Start" feature keeps the indoor fan off during heating until the indoor coil is warm, preventing cold air from blowing into the room.

Q: Does the unit include a dehumidifying mode?

A: Yes, it has a dehumidifying function. Sensors monitor temperature and adjust settings to effectively remove moisture from the air.

Q: How often should the washable pre-filter be cleaned?

A: To ensure optimal performance, the pre-filter should be cleaned at least once a month.

Q: Does the unit help improve air quality?

A: Yes, it includes an anti-fungal filter that captures dust and bacteria, enhancing indoor air quality. The filter is also washable for repeated use.

Q: How does Sleep Mode function?

A: Sleep Mode gradually adjusts the temperature over one hour and then automatically turns off the unit to enhance comfort and save energy.

Q: What is the "Condensate Protection" feature?

A: This feature uses an internal condensate pump with a 27.5-inch lift to remove excess moisture, protecting both the unit and your home from water damage.