What is the SEER2 rating of the Fujitsu AOUH42KUAS1?

The Fujitsu AOUH42KUAS1 is rated at up to 19.0 SEER2 and 10.8 EER2 for cooling and up to 10.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 17.3-19.0.

Is the Fujitsu AOUH42KUAS1 good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 37,000 BTU/h at 5°F with a COP of 2.36, so it is still 2.4 times as efficient as electric resistance heat at that temperature.

How much does the Fujitsu AOUH42KUAS1 cost to run per year?

At its rated efficiency it costs about $1,040-$2,840 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,290 in Phoenix and $2,379 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 Fujitsu AOUH42KUAS1?

ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use FUJITSU AUUH42KUAS, FUJITSU ARUH42KUAS.

42,000 BTU mini-split heat pump · AIRSTAGE H-series

Fujitsu AOUH42KUAS1

Below average cooling efficiency and average heating efficiency for a 42,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #53 of 61 42,000 BTU mini-splits for cooling efficiency, and costs about $1,182 a year to run in a mixed climate like Atlanta.

SEER2: 19.0 Cooling efficiency over a season
Below average · beats 9%
HSPF2: 10.4 Heating efficiency over a season
Average · beats 57%
EER2: 10.8 Cooling efficiency on a 95°F day
Below average · beats 7%
Heat at 5°F: 37,000 BTU/h79% of its 47°F output
Excellent · beats 90%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 37,000 BTU/h at 5°F.
You want steady temperatures and quiet running - the compressor varies its speed.

Think twice if…

Cooling cost matters most - its SEER2 is below average for mini-splits.

Calculate my running cost

Details

Specifications42,000 BTU, R-32

General
Brand	Fujitsu
Outdoor unit model	AOUH42KUAS1
Series	AIRSTAGE H-series
Type	Mini-split heat pump
Nominal size	42,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-32
Connected (smart) capable	No
On the market since	October 12, 2024
Last certified	April 17, 2026
Cooling
SEER2Seasonal efficiency, higher is better	19.0 (range 17.3-19.0)
EER2Efficiency at 95°F outdoors	10.3-10.8
Cooling capacity	42,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	10.2-10.4
Capacity at 47°F	47,000 BTU/h
Capacity at 17°F	32,000 BTU/h
Capacity at 5°F	37,000 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	2.23-2.36
ENERGY STAR cold climate	Yes

Heating output as it gets colder79% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with AUUH42KUAS at the standard test temperatures, in BTU/h:

Certified matchups2 indoor units

The same outdoor unit scores differently with each indoor unit. Ask your installer for the AHRI reference number of the exact system you are quoted.

Indoor unit	SEER2	EER2	HSPF2	Heat @5°F	AHRI ref.
AUUH42KUAS FUJITSU · cold climate	19.0	10.8	10.4	37,000	215812200
ARUH42KUAS FUJITSU · cold climate	17.3	10.3	10.2	37,000	215812202

Yearly running cost in 10 large cities$1,040-$2,840

Phoenix, AZ$1,290/yr
Miami, FL$1,040/yr
Houston, TX$1,157/yr
Atlanta, GA$1,182/yr
Los Angeles, CA$1,153/yr
New York, NY$2,840/yr
Chicago, IL$2,308/yr
Denver, CO$1,921/yr
Seattle, WA$1,182/yr
Minneapolis, MN$2,379/yr

At each state's average electricity price and the city's typical heating and cooling hours.

Questions5

What is the SEER2 rating of the Fujitsu AOUH42KUAS1?: The Fujitsu AOUH42KUAS1 is rated at up to 19.0 SEER2 and 10.8 EER2 for cooling and up to 10.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 17.3-19.0.
Is the Fujitsu AOUH42KUAS1 good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 37,000 BTU/h at 5°F with a COP of 2.36, so it is still 2.4 times as efficient as electric resistance heat at that temperature.
How much does the Fujitsu AOUH42KUAS1 cost to run per year?: At its rated efficiency it costs about $1,040-$2,840 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,290 in Phoenix and $2,379 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 Fujitsu AOUH42KUAS1?: ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use FUJITSU AUUH42KUAS, FUJITSU ARUH42KUAS.
What refrigerant does the Fujitsu AOUH42KUAS1 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.

Heat pump $1,284/yrYou save $963/yrSee details ↓

1. Where you live

StateCityElectricity ¢ per kWh

Adjust heating and cooling hours

Filled in from your city's climate. Change them if you run the system much more or less than usual.

Cooling hours full-load hours per yearHeating hours full-load hours per year

2. The heat pump Fujitsu AOUH42KUAS1

Find a model (fills in the ratings below)

SEER2 cooling efficiencyHSPF2 heating efficiencyCooling capacity BTU/hHeating capacity BTU/h

3. What it replaces

Current heatingFurnace efficiency (AFUE %)Gas price, $/thermCurrent coolingOld AC rating SEER2 (10 ≈ 15+ years old)

4. Price replace the example with your quote

Installed price, $Rebates and incentives, $ utility, state

Heat pump, per year: $1,284
Current system, per year: $2,247
You save per year: $963
Payback: 16.6 years
Net after 10 years: -$6,368

Cooling $778Heating $506Electricity used: 8,027 kWhSaved vs. a minimum-efficiency heat pump: $451

Estimates use the unit's rated SEER2 and HSPF2, full-load hours derived from NOAA 1991-2020 degree days, average residential electricity prices from the U.S. EIA (12 months to July 2026) and fuel prices from EIA (2025 for natural gas, week of 2026-10-05 for propane and heating oil). Very cold days that need backup heat are not modelled. Federal minimum for comparison: 14.3 SEER2 / 7.5 HSPF2.

Similar 42,000 BTU models

DELLA 048-TLP-MODU-1D5 · cold climate19.5 SEER2 · 9.0 HSPF2
LG KUSUB421A · cold climate18.5 SEER2 · 9.5 HSPF2
Westinghouse WHP42M5A21S · cold climate20.0 SEER2 · 9.0 HSPF2
GE Appliances ASH4248UCDD · cold climate18.0 SEER2 · 8.8 HSPF2
OLMO OS-MSR42-230VO · cold climate20.0 SEER2 · 9.0 HSPF2
TOSOT TGWHD-42ND · cold climate17.0 SEER2 · 8.5 HSPF2
Friedrich FPHMR42A3A · cold climate20.0 SEER2 · 9.0 HSPF2
Mitsubishi Electric PUZ-HA42NKA2 · cold climate16.3 SEER2 · 9.3 HSPF2

See all 61 42,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of April 17, 2026. How we use the data.