What is the SEER2 rating of the ZERO ZSOV-24HDM-US?

The ZERO ZSOV-24HDM-US is rated at up to 21.2 SEER2 and 12.5 EER2 for cooling and up to 11.2 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 3 certified matchups SEER2 ranges from 18.0-21.2.

Is the ZERO ZSOV-24HDM-US good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 20,000 BTU/h at 5°F with a COP of 2.30, so it is still 2.3 times as efficient as electric resistance heat at that temperature.

How much does the ZERO ZSOV-24HDM-US cost to run per year?

At its rated efficiency it costs about $532-$1,412 a year in electricity in large U.S. cities, depending on climate and local rates - for example $654 in Phoenix and $1,179 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 ZERO ZSOV-24HDM-US?

ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use ZEV-24HDM-US, ZDV-24HDM-US, ZAV-24HDM-US.

What refrigerant does the ZERO ZSOV-24HDM-US use?

It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and R-32.

24,000 BTU mini-split heat pump · ZMSB Series

ZERO ZSOV-24HDM-US

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

Ranks #255 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $592 a year to run in a mixed climate like Atlanta.

SEER2: 21.2 Cooling efficiency over a season
Below average · beats 35%
HSPF2: 11.2 Heating efficiency over a season
Very good · beats 79%
EER2: 12.5 Cooling efficiency on a 95°F day
Average · beats 44%
Heat at 5°F: 20,000 BTU/h76% of its 47°F output
Very good · beats 86%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 20,000 BTU/h at 5°F.
It will heat most of the year - its HSPF2 beats 79% of mini-splits.
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.
You want the newest refrigerant - it uses R-410A, which is being phased down.

Calculate my running cost

Details

Specifications24,000 BTU, R-410A

General
Brand	ZERO
Outdoor unit model	ZSOV-24HDM-US
Series	ZMSB Series
Type	Mini-split heat pump
Nominal size	24,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-410A
Connected (smart) capable	No
On the market since	March 27, 2024
Last certified	April 22, 2026
Cooling
SEER2Seasonal efficiency, higher is better	21.2 (range 18.0-21.2)
EER2Efficiency at 95°F outdoors	11.7-12.5
Cooling capacity	23,000-24,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	8.1-11.2
Capacity at 47°F	24,000-25,000 BTU/h
Capacity at 17°F	16,000-20,000 BTU/h
Capacity at 5°F	14,000-20,000 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	1.90-2.30
ENERGY STAR cold climate	Yes

Heating output as it gets colder76% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with ZEV-24HDM-US at the standard test temperatures, in BTU/h:

Certified matchups3 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.
ZEV-24HDM-US · cold climate	21.2	12.5	10.3	18,200	212928564
ZDV-24HDM-US · cold climate	19.0	12.5	11.2	20,000	212928560
ZAV-24HDM-US	18.0	11.7	8.1	14,000	213867393

Yearly running cost in 10 large cities$532-$1,412

Phoenix, AZ$654/yr
Miami, FL$532/yr
Houston, TX$586/yr
Atlanta, GA$592/yr
Los Angeles, CA$576/yr
New York, NY$1,412/yr
Chicago, IL$1,146/yr
Denver, CO$953/yr
Seattle, WA$585/yr
Minneapolis, MN$1,179/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 ZERO ZSOV-24HDM-US?: The ZERO ZSOV-24HDM-US is rated at up to 21.2 SEER2 and 12.5 EER2 for cooling and up to 11.2 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 3 certified matchups SEER2 ranges from 18.0-21.2.
Is the ZERO ZSOV-24HDM-US good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 20,000 BTU/h at 5°F with a COP of 2.30, so it is still 2.3 times as efficient as electric resistance heat at that temperature.
How much does the ZERO ZSOV-24HDM-US cost to run per year?: At its rated efficiency it costs about $532-$1,412 a year in electricity in large U.S. cities, depending on climate and local rates - for example $654 in Phoenix and $1,179 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 ZERO ZSOV-24HDM-US?: ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use ZEV-24HDM-US, ZDV-24HDM-US, ZAV-24HDM-US.
What refrigerant does the ZERO ZSOV-24HDM-US use?: It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and 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 $648/yrYou save $605/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 ZERO ZSOV-24HDM-US

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: $648
Current system, per year: $1,254
You save per year: $605
Payback: 14.9 years
Net after 10 years: -$2,946

Cooling $398Heating $250Electricity used: 4,053 kWhSaved vs. a minimum-efficiency heat pump: $316

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

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Star Air Kontrol SAK-24CONS/220V · cold climate21.2 SEER2 · 10.3 HSPF2
Arcoaire D5CSHAH24AAK · cold climate21.2 SEER2 · 13.5 HSPF2
Mitsubishi Electric SUZ-AA24NL21.2 SEER2 · 10.0 HSPF2
Mitsubishi Electric MUZ-GS24NAHZ · cold climate21.5 SEER2 · 9.0 HSPF2
Mitsubishi Electric SUZ-CA24NLH21.2 SEER2 · 9.7 HSPF2
Blueridge BMKH2422/O · cold climate21.5 SEER2 · 9.5 HSPF2
Bosch BMS500-AAS024-1CSXHD · cold climate21.0 SEER2 · 13.5 HSPF2

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

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of April 22, 2026. How we use the data.