SplitAtlas

LG / Mega R-32

LG Mega 12k R-32 115V Mini-Split

Certified capacity
11,000 BTU/h[2]
SEER2
20 SEER2[2]
Heating floor
5 F[1]
Voltage
115V[1]
Install path
Professional install

The Mega 12k on 115V is LG's volume system: SEER2 20 on a standard circuit, certifying 11,000 BTU rather than a round 12,000 - size from the certificate. Rated to +5F, so this is a cooling-led choice. LG's cold-capable systems are the ARTCOOL Deluxe (-31F) and the LGRED-badged lines; the Mega name signals volume pricing, not winter performance.

1 zoneProfessional installCurrent

Refrigerant generation

R-32 - current-generation refrigerant

This system's warranty depends on licensed installation — get quotes from installers in your area.

Get installation quotes
Error Codes
LG Mega R-32 12,000 BTU (115V) mini-split heat pump indoor wall unit and outdoor condenser

Image: HVACDirect

Data completeness: 95%
Last sourced
Jul 23, 2026

SplitAtlas score

8.0 / 10

Methodology
Cooling efficiencyBelow average

(20.0 SEER2) among 12k systems

Heating efficiencyBottom quartile

(9.0 HSPF2) among 12k systems

Cold-weather performanceBelow average

(5F certified capacity: 76.4% of the 47F rating; 5 F heating floor) among 12k systems

NoiseTop quartile

(21 dBA indoor min / 50 dBA outdoor) among 12k systems

WarrantyTop quartile

(10 yr parts / 10 yr compressor) across the catalogue

Feature setBelow average

(4 verified features) across the catalogue

Documentation & partsTop quartile

(9 manuals; spec sheet; 51 error-code rows) across the catalogue

Not evaluated

  • Installation accessibility — not applicable (professional install)N/A

    professional install - DIY-accessibility not applicable

  • Price-to-value — not evaluatedN/A

    This is a professionally installed, quote-only system, so we can't score its price. Get an installed quote to compare real cost.

    Get a quote

Key ratings

Rated cooling

11,000BTU/h[2]

Rated heating

11,000BTU/h[2]

Buyer review snapshot

Install difficulty

Professional install
  • Electrical: 115V; MCA 15 A; breaker/fuse 20 A.
  • Line set: connection type not sourced; precharged 24.6 ft; max 49.2 ft.

Alternatives

Availability and price context

  • Last seen at HVACDirect on Jul 23, 2026: $1,259.00. Open the listing for today's price. Warranty condition: The online source must be expressly authorized by LG; the system must also satisfy LG's qualified-system installation terms.

Purchase channel policy

LG allows the online-purchase path only when the online source is expressly authorized by LG; an online purchase from a non-authorized source voids the limited warranty.

Warranty impact
The limited warranty is void and LG has no liability when the system is purchased online from a source not expressly authorized by LG.
Installation condition
The online source must be expressly authorized by LG; the system must also satisfy LG's qualified-system installation terms.
Authorized channel
Expressly authorized LG source with qualified installation by a trained, licensed HVAC contractor under LG warranty terms.

Buying online can keep warranty coverage only when the seller is expressly authorized by LG; confirm that status and the qualified installation path before purchase.

Compare online-purchase warranty rules by brand

Source: LG Electronics U.S.A., Inc.: LG R32 Residential / Light Commercial Systems Warranty Card; retrieved Aug 15, 2026.

Source date

Model data sourced
Jul 23, 2026
Page reviewed
Jul 23, 2026
Source-backed records
4
Newest source retrieved
Jul 23, 2026

Warranty tiers

Base
5 yr parts / 7 yr compressor - standard coverage
Registered
10 yr parts / 10 yr compressor - registration within 60 days of startup, by an installer with current LG training and an HVAC license

The score uses Registered. Additional published terms are shown for reference and not counted in the score.

Review methodology

Strengths

  • SEER2 20 on a standard 115V circuit, keeping install cost down.

Weaknesses

  • Certifies 11,000 BTU, not 12,000.
  • +5F heating floor - Mega is not a cold-climate line.

Climate suitability

Minimum heating ambient
5 F[1]
Certified heating at 5F
8,400 BTU/h[2]
Maximum heating at 5F (manufacturer)
8,400 BTU/h[1]
Rated heating at 17F
8,000 BTU/h[2]
Rated heating at 47F
11,000 BTU/h[2]

Specifications

Show
Manufacturer
LG
Brand
LG
Product line
Mega R-32
Model number
KNSAC121B indoor / KUSAC121B outdoor
Indoor unit model
KNSAC121B
Outdoor unit model
KUSAC121B
Number of zones
1
Max indoor units
not published
Rated cooling capacity
11,000 BTU/h[2]
Rated heating capacity
11,000 BTU/h[2]
Voltage
115V[1]
MCA
15 A[1]
Maximum fuse or breaker size
20 A[1]
Breaker needed
not published
SEER2
20 SEER2[2]
EER2
12.3 EER2[2]
HSPF2 (Region 4)
9 HSPF2[2]
HSPF2 (Region 5)
not published
COP
not published
COP at 47F
not published
COP at 5F
1.8 COP[2]
Minimum outdoor heating temperature
5 F[1]
Minimum outdoor cooling temperature
14 F[1]
Maximum outdoor temperature
118 F[1]
Indoor noise range
cooling 21-42; heating 28-42 dB(A)[1]
Outdoor noise rating
50 dBA[1]
Indoor weight
19.2 lb[1]
Outdoor weight
55.3 lb[1]
Refrigerant
R-32[2]
Refrigerant charge
24.64 oz[1]
Manufacturer coverage
not published
Line-set size
1/4 in liquid / 3/8 in suction
Included line-set length
LG publishes field-supplied flared line sizes, standard/pre-charge length, and line limits; no included consumer line-set length is published for the professional system.
Maximum line-set length
49.2 ft[1]
Max line set per indoor
not published
Maximum elevation difference
23 ft[1]
Max height between indoor units
not published
Wi-Fi support
supported[1]
Energy Star status
ENERGY STAR certified[3]
AHRI certification number
214931172[2]
Warranty
Base: 5 yr parts / 7 yr compressor (standard coverage); Registered: 10 yr parts / 10 yr compressor (registration within 60 days of startup, by an installer with current LG training and an HVAC license). Score uses Registered.. Standard 5-year parts and 7-year compressor coverage; qualified registered installations extend to 10 years total parts and compressor coverage.
Install path
Professional install
Retail price
last seen at HVACDirect on Jul 23, 2026: $1,259.00
Available retailers
HVACDirect
Manual links
AHRI Directory public detail record 214931172, ENERGY STAR exact-match query for KUSAC121B/KNSAC121B, LG Mega 115V R-32 engineering manual, LG Mega 115V R-32 installation manual, LG HVAC API product metadata KSSAC121B, HVACDirect exact product page KSSAC121B, LG official support pages: [LG Air Conditioner] Guide to Error Codes; [LG Air Conditioner] How to Check Air Conditioner Error Codes; LG status-display help articles; LG Korea [LG Air Conditioner] Air conditioner error inquiry cross-check, KSSAC121B LG Mega 115V R-32 submittal, LG R32 Residential / Light Commercial Systems Warranty Card
Specification sheet
KSSAC121B LG Mega 115V R-32 submittal
Last sourced date
Jul 23, 2026

Retail purchase context

Dealer-installation warranty note

Buying online can keep warranty coverage only when the seller is expressly authorized by LG; confirm that status and the qualified installation path before purchase.

Installation condition: The online source must be expressly authorized by LG; the system must also satisfy LG's qualified-system installation terms.

Dealer path: Expressly authorized LG source with qualified installation by a trained, licensed HVAC contractor under LG warranty terms.

Some retailer links may earn us a commission at no extra cost; paid relationships never change scores or recommendations. Affiliate disclosure

Paid link

Dealer-installation warranty note

Buying online can keep warranty coverage only when the seller is expressly authorized by LG; confirm that status and the qualified installation path before purchase.

Check price at HVACDirect

Last seen at HVACDirect on Jul 23, 2026: $1,259

Electrical requirements

Show
Voltage
not published
Voltage range
115V[1]
Phase
1[1]
Frequency
60 Hz[1]
MCA
15 A[1]
Breaker needed
not published
Maximum breaker size
20 A[1]
Maximum fuse size
not published
Maximum cooling current
not published
Maximum heating current
not published
Manufacturer wire notes
14 AWG minimum four-conductor indoor-outdoor connection cable; field supplied[1]

Installation considerations

Show
Liquid line
1/4 in[1]
Suction line
3/8 in[1]
Line connection type
not published
Precharged length
24.6 ft[1]
Included line-set length
LG publishes field-supplied flared line sizes, standard/pre-charge length, and line limits; no included consumer line-set length is published for the professional system.
Maximum line-set length
49.2 ft[1]
Max line set per indoor
not published
Max height between indoor units
not published
Indoor dimensions
not published
Outdoor dimensions
not published
Indoor weight
19.2 lb[1]
Outdoor weight
55.3 lb[1]
Drain size
not published

Related systems and guides

Frequently asked questions

Can I install the LG Mega R-32 12,000 BTU (115V) myself, or do I need a pro?
LG Mega R-32 12,000 BTU (115V) is built for professional installation: the line set must be flared, evacuated, and charged, which requires EPA-certified refrigerant handling. Installing it outside the manufacturer's requirements can void the warranty, so budget for a qualified HVAC installer.
Will the LG Mega R-32 12,000 BTU (115V) keep heating in a cold winter?
The AHRI/ENERGY STAR certification lists 8,400 BTU/h of heating capacity at 5F. Rated heating operation extends down to 5 F. Certified heating efficiency is 9 HSPF2. Match those numbers against your climate's design temperature - in cold regions, output at 5F matters far more than the nameplate capacity measured at 47F.
What electrical circuit does the LG Mega R-32 12,000 BTU (115V) need?
Published electrical requirements: 115V voltage, 15 A minimum circuit ampacity, and 20 A maximum breaker or fuse sizing. Confirm the final circuit against the unit nameplate and local code with a licensed electrician.
How far can the outdoor unit be from the indoor head?
The published maximum line-set length is 49.2 ft. The outdoor unit's factory charge covers up to 24.6 ft of line; longer runs need added refrigerant. Measure the planned routing before ordering.
What warranty does the LG Mega R-32 12,000 BTU (115V) carry?
The manufacturer publishes these warranty tiers: Base: 5 yr parts / 7 yr compressor (standard coverage); Registered: 10 yr parts / 10 yr compressor (registration within 60 days of startup, by an installer with current LG training and an HVAC license). Score uses Registered.. Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.

Data sources

Show
  1. LG Electronics U.S.A., Inc.: KSSAC121B submittalSourced - manufacturer technical document

    Covers Frequency, electrical_spec.guaranteed_voltage_range, Maximum breaker size, Minimum circuit ampacity, Phase, Manufacturer wire notes and more

  2. AHRI: AHRI Directory public detail record 214931172Sourced - AHRI directory

    Covers AHRI certification number, Rated cooling capacity, COP at 5F, EER2, Rated heating capacity, HSPF2 (Region 4) and more

  3. ENERGY STAR: ENERGY STAR exact-match record for KUSAC091A/KNSAC091ASourced - secondary source

    Covers Energy Star status

  4. LG Electronics U.S.A., Inc.: LG R32 Residential / Light Commercial Systems Warranty CardSourced - manufacturer technical document

    Covers Legacy compressor warranty value, Legacy warranty value, Registered compressor warranty, Registered warranty conditions, Registered parts warranty, Base compressor warranty and more

Last updated

Jul 23, 2026