What is the SEER2 rating of the Guardian UPC24CN23STG1?

The Guardian UPC24CN23STG1 is rated at up to 21.0 SEER2 and 12.0 EER2 for cooling and up to 10.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 15 certified matchups SEER2 ranges from 18.0-21.0.

Is the Guardian UPC24CN23STG1 good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 24,200 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 Guardian UPC24CN23STG1 cost to run per year?

At its rated efficiency it costs about $537-$1,442 a year in electricity in large U.S. cities, depending on climate and local rates - for example $663 in Phoenix and $1,206 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 Guardian UPC24CN23STG1?

ENERGY STAR lists 15 certified combinations for this outdoor unit. The highest-rated ones use GUARDIAN UNI24HW23STG1, Coleman UNI24HW23STG1, LUXAIRE UNI24HW23STG1.

24,000 BTU mini-split heat pump · UPAC

Guardian UPC24CN23STG1

Below average cooling efficiency and average heating efficiency for a 24,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #273 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $603 a year to run in a mixed climate like Atlanta.

SEER2: 21.0 Cooling efficiency over a season
Below average · beats 30%
HSPF2: 10.5 Heating efficiency over a season
Average · beats 61%
EER2: 12.0 Cooling efficiency on a 95°F day
Below average · beats 25%
Heat at 5°F: 24,200 BTU/h100% of its 47°F output
Average · beats 48%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 24,200 BTU/h at 5°F.
You want steady temperatures and quiet running - the compressor varies its speed.
You want a choice of indoor units - 15 certified pairings.

Think twice if…

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

Calculate my running cost

Details

Specifications24,000 BTU, R-454B

General
Brand	Guardian
Also sold as	Luxaire, Coleman
Outdoor unit model	UPC24CN23STG1
Series	UPAC
Type	Mini-split heat pump
Nominal size	24,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-454B
Connected (smart) capable	No
On the market since	November 1, 2024
Last certified	June 12, 2026
Cooling
SEER2Seasonal efficiency, higher is better	21.0 (range 18.0-21.0)
EER2Efficiency at 95°F outdoors	11.7-12.0
Cooling capacity	18,000-24,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	9.5-10.5
Capacity at 47°F	18,000-24,000 BTU/h
Capacity at 17°F	16,600-20,200 BTU/h
Capacity at 5°F	19,500-24,200 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 colder100% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with UNI24HW23STG1 at the standard test temperatures, in BTU/h:

Certified matchups15 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.
UNI24HW23STG1 GUARDIAN	21.0	12.0	10.0	24,000	216017246
UNI24HW23STG1 Coleman	21.0	12.0	10.0	24,000	216572160
UNI24HW23STG1 LUXAIRE	21.0	12.0	10.0	24,000	216572171
UNI24CS23STG1 GUARDIAN · cold climate	20.0	12.0	10.5	24,000	216019853
UNI24CS23STG1 Coleman · cold climate	20.0	12.0	10.5	24,000	216566109
UNI24CS23STG1 LUXAIRE · cold climate	20.0	12.0	10.5	24,000	216566111
UNI24DT23STG1 GUARDIAN · cold climate	19.0	11.7	9.5	24,000	216445266
UNI24DT23STG1 LUXAIRE · cold climate	19.0	11.7	9.5	24,000	216566115
UNI24DT23STG1 Coleman · cold climate	19.0	11.7	9.5	24,000	216566113
JHE18B5AB2SS1 · cold climate	18.0	12.0	9.5	19,500	217050611
JHE24B5AC2SS1 · cold climate	18.0	11.7	9.5	24,200	217050612
JHE18B5AB2SS1 · cold climate	18.0	12.0	9.5	19,500	217050614
JHE24B5AC2SS1 · cold climate	18.0	11.7	9.5	24,200	217050615
JHE18B5AB2SS1 · cold climate	18.0	12.0	9.5	19,500	217050617
JHE24B5AC2SS1 · cold climate	18.0	11.7	9.5	24,200	217050618

Yearly running cost in 10 large cities$537-$1,442

Phoenix, AZ$663/yr
Miami, FL$537/yr
Houston, TX$594/yr
Atlanta, GA$603/yr
Los Angeles, CA$587/yr
New York, NY$1,442/yr
Chicago, IL$1,171/yr
Denver, CO$974/yr
Seattle, WA$599/yr
Minneapolis, MN$1,206/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 Guardian UPC24CN23STG1?: The Guardian UPC24CN23STG1 is rated at up to 21.0 SEER2 and 12.0 EER2 for cooling and up to 10.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 15 certified matchups SEER2 ranges from 18.0-21.0.
Is the Guardian UPC24CN23STG1 good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 24,200 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 Guardian UPC24CN23STG1 cost to run per year?: At its rated efficiency it costs about $537-$1,442 a year in electricity in large U.S. cities, depending on climate and local rates - for example $663 in Phoenix and $1,206 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 Guardian UPC24CN23STG1?: ENERGY STAR lists 15 certified combinations for this outdoor unit. The highest-rated ones use GUARDIAN UNI24HW23STG1, Coleman UNI24HW23STG1, LUXAIRE UNI24HW23STG1.
What refrigerant does the Guardian UPC24CN23STG1 use?: It uses R-454B.

Running cost and savings

Pre-filled with this model. Pick your city and what you heat with today; everything else is optional.

Heat pump $658/yrYou save $579/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 Guardian UPC24CN23STG1

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: $658
Current system, per year: $1,238
You save per year: $579
Payback: 15.5 years
Net after 10 years: -$3,208

Cooling $402Heating $256Electricity used: 4,114 kWhSaved vs. a minimum-efficiency heat pump: $291

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 24,000 BTU models

York YRACXJ24WHBA · cold climate21.0 SEER2 · 11.0 HSPF2
Hisense AOU-24U3T25U · cold climate21.0 SEER2 · 10.5 HSPF2
York YRACGJ24WHAA · cold climate21.0 SEER2 · 11.0 HSPF2
Innovair QOS24H2BH0A · cold climate21.0 SEER2 · 10.5 HSPF2
Hitachi RAC-XJ24WHAA · cold climate21.0 SEER2 · 11.0 HSPF2
1HVAC SC-27Z-HH-M4B · cold climate21.0 SEER2 · 10.0 HSPF2
Deye DWLC2-24KR2(US) · cold climate21.0 SEER2 · 11.0 HSPF2
AireForce DXH24FMK3IH · cold climate21.0 SEER2 · 10.0 HSPF2

See all 430 24,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 12, 2026. How we use the data.