18,000 BTU mini-split heat pump · KUSXA181A
LG KUSXA181A
Below average cooling efficiency and average heating efficiency for a 18,000 BTU mini-split heat pump, and certified for cold climates.
Ranks #377 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $504 a year to run in a mixed climate like Atlanta.
- SEER2
- 20.5 Cooling efficiency over a seasonBelow average · beats 24%
- HSPF2
- 10.0 Heating efficiency over a seasonAverage · beats 43%
- EER2
- 13.2 Cooling efficiency on a 95°F dayAverage · beats 69%
- Heat at 5°F
- 24,000 BTU/h100% of its 47°F outputAverage · beats 48%
A good fit if…
- Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 24,000 BTU/h at 5°F.
- You want steady temperatures and quiet running - the compressor varies its speed.
- You want a choice of indoor units - 10 certified pairings.
Think twice if…
- Cooling cost matters most - its SEER2 is below average for mini-splits.
Details
Specifications
| General | |
|---|---|
| Brand | LG |
| Outdoor unit model | KUSXA181A |
| Series | KUSXA181A |
| Type | Mini-split heat pump |
| Nominal size | 18,000 BTU |
| CompressorVariable-speed units run longer at low power | Continuously variable |
| Refrigerant | R-32 |
| Connected (smart) capable | No |
| On the market since | December 2, 2024 |
| Last certified | September 22, 2026 |
| Cooling | |
| SEER2Seasonal efficiency, higher is better | 20.5 (range 15.2-20.5) |
| EER2Efficiency at 95°F outdoors | 11.5-13.5 |
| Cooling capacity | 17,000-18,000 BTU/h |
| Heating | |
| HSPF2Seasonal efficiency, higher is better | 8.1-10.0 |
| Capacity at 47°F | 20,000 BTU/h |
| Capacity at 17°F | 12,900-13,600 BTU/h |
| Capacity at 5°F | 17,000-24,000 BTU/h |
| COP at 5°F2.0 = twice as efficient as a space heater | 1.80-2.00 |
| ENERGY STAR cold climate | Yes |
Heating output as it gets colder
Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with KNUDB181A at the standard test temperatures, in BTU/h:
Certified matchups
The same outdoor unit scores differently with each indoor unit and furnace. Ask your installer for the AHRI reference number of the exact system you are quoted.
| Indoor unit | Furnace | SEER2 | EER2 | HSPF2 | Heat @5°F | AHRI ref. |
|---|---|---|---|---|---|---|
| KNUDB181A · cold climate | - | 20.5 | 13.2 | 9.5 | 20,000 | 214825952 |
| KNSFB181A · cold climate | - | 20.0 | 12.5 | 9.5 | 17,000 | 216592037 |
| KNUFB181A · cold climate | - | 20.0 | 12.5 | 9.5 | 17,000 | 216778956 |
| KNSLA181A · cold climate | - | 18.0 | 13.5 | 10.0 | 24,000 | 215588567 |
| KNSLA181A · cold climate | - | 18.0 | 13.5 | 10.0 | 24,000 | 217284907 |
| KNUJB181A · cold climate | - | 17.5 | 12.4 | 9.2 | 20,000 | 214796350 |
| LKMMA18B1 · cold climate | LNA**060B1 | 17.0 | 11.5 | 9.5 | 19,000 | 217284946 |
| LKMMA18B1 · cold climate | LNAEA080B1 | 17.0 | 11.5 | 9.5 | 19,000 | 218770189 |
| LKMMA18A1 · cold climate | - | 15.2 | 11.5 | 8.1 | 18,000 | 216445254 |
| LKMMA18B1 · cold climate | - | 15.2 | 11.5 | 8.1 | 18,000 | 216445255 |
Yearly running cost in 10 large cities
- Phoenix, AZ$528/yr
- Miami, FL$415/yr
- Houston, TX$474/yr
- Atlanta, GA$504/yr
- Los Angeles, CA$495/yr
- New York, NY$1,233/yr
- Chicago, IL$1,006/yr
- Denver, CO$841/yr
- Seattle, WA$520/yr
- Minneapolis, MN$1,043/yr
At each state's average electricity price and the city's typical heating and cooling hours.
Questions
- What is the SEER2 rating of the LG KUSXA181A?
- The LG KUSXA181A is rated at up to 20.5 SEER2 and 13.2 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 10 certified matchups SEER2 ranges from 15.2-20.5.
- Is the LG KUSXA181A good for cold climates?
- Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 24,000 BTU/h at 5°F with a COP of 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
- How much does the LG KUSXA181A cost to run per year?
- At its rated efficiency it costs about $415-$1,233 a year in electricity in large U.S. cities, depending on climate and local rates - for example $528 in Phoenix and $1,043 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
- Which indoor units work with the LG KUSXA181A?
- ENERGY STAR lists 10 certified combinations for this outdoor unit. The highest-rated ones use KNUDB181A, KNSFB181A, KNUFB181A.
- What refrigerant does the LG KUSXA181A use?
- It uses R-32.
Running cost and savings
Pre-filled with this model. Pick your city and what you heat with today; everything else is optional.
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See all 465 18,000 BTU mini-splits, ranked
Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of September 22, 2026. How we use the data.