What is the SEER2 rating of the NOVAIR LEA24SZ35SK-O?

The NOVAIR LEA24SZ35SK-O is rated at up to 22.3 SEER2 and 12.5 EER2 for cooling and up to 11.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 21.5-22.3.

Is the NOVAIR LEA24SZ35SK-O good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 25,000 BTU/h at 5°F with a COP of 2.21, so it is still 2.2 times as efficient as electric resistance heat at that temperature.

How much does the NOVAIR LEA24SZ35SK-O cost to run per year?

At its rated efficiency it costs about $509-$1,558 a year in electricity in large U.S. cities, depending on climate and local rates - for example $655 in Phoenix and $1,323 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 NOVAIR LEA24SZ35SK-O?

ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use LEA24UUSK-I, 2LEA24UUSK-I.

What refrigerant does the NOVAIR LEA24SZ35SK-O 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 · LEA SERIES

NOVAIR LEA24SZ35SK-O

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

Ranks #167 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $633 a year to run in a mixed climate like Atlanta.

SEER2: 22.3 Cooling efficiency over a season
Average · beats 53%
HSPF2: 11.4 Heating efficiency over a season
Very good · beats 82%
EER2: 12.5 Cooling efficiency on a 95°F day
Average · beats 44%
Heat at 5°F: 25,000 BTU/h88% of its 47°F output
Very good · beats 81%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 25,000 BTU/h at 5°F.
It will heat most of the year - its HSPF2 beats 82% of mini-splits.
You want steady temperatures and quiet running - the compressor varies its speed.

Think twice if…

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	NOVAIR
Outdoor unit model	LEA24SZ35SK-O
Series	LEA 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	January 1, 2023
Last certified	June 13, 2026
Cooling
SEER2Seasonal efficiency, higher is better	22.3 (range 21.5-22.3)
EER2Efficiency at 95°F outdoors	12.5-13.0
Cooling capacity	23,000-24,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	10.3-11.4
Capacity at 47°F	26,000-29,000 BTU/h
Capacity at 17°F	18,900-21,200 BTU/h
Capacity at 5°F	23,000-25,000 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	1.80-2.21
ENERGY STAR cold climate	Yes

Heating output as it gets colder88% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with LEA24UUSK-I 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.
LEA24UUSK-I · cold climate	22.3	12.5	10.3	23,000	209416880
2LEA24UUSK-I · cold climate	21.5	13.0	11.4	25,000	211709685

Yearly running cost in 10 large cities$509-$1,558

Phoenix, AZ$655/yr
Miami, FL$509/yr
Houston, TX$588/yr
Atlanta, GA$633/yr
Los Angeles, CA$624/yr
New York, NY$1,558/yr
Chicago, IL$1,274/yr
Denver, CO$1,066/yr
Seattle, WA$661/yr
Minneapolis, MN$1,323/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 NOVAIR LEA24SZ35SK-O?: The NOVAIR LEA24SZ35SK-O is rated at up to 22.3 SEER2 and 12.5 EER2 for cooling and up to 11.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 21.5-22.3.
Is the NOVAIR LEA24SZ35SK-O good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 25,000 BTU/h at 5°F with a COP of 2.21, so it is still 2.2 times as efficient as electric resistance heat at that temperature.
How much does the NOVAIR LEA24SZ35SK-O cost to run per year?: At its rated efficiency it costs about $509-$1,558 a year in electricity in large U.S. cities, depending on climate and local rates - for example $655 in Phoenix and $1,323 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 NOVAIR LEA24SZ35SK-O?: ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use LEA24UUSK-I, 2LEA24UUSK-I.
What refrigerant does the NOVAIR LEA24SZ35SK-O 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 $664/yrYou save $656/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 NOVAIR LEA24SZ35SK-O

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: $664
Current system, per year: $1,319
You save per year: $656
Payback: 13.7 years
Net after 10 years: -$2,444

Cooling $379Heating $285Electricity used: 4,148 kWhSaved vs. a minimum-efficiency heat pump: $360

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

PerfectAire 3PAMSHH24-SZO · cold climate22.3 SEER2 · 11.5 HSPF2
Goodman MSH243G22MCAA · cold climate22.3 SEER2 · 10.5 HSPF2
Mitsutomo HO-SZ24-AB-Q · cold climate22.3 SEER2 · 11.5 HSPF2
ZERO ZMSB-24HV-USHHC · cold climate22.3 SEER2 · 10.3 HSPF2
MDV MOD30-24HFN1-MU0W · cold climate22.3 SEER2 · 11.5 HSPF2
Sea Breeze MZ27H424ZMO · cold climate22.3 SEER2 · 9.7 HSPF2
LBG Products LBHB24DVWO · cold climate22.3 SEER2 · 11.5 HSPF2
Tempstar DLCMHBH24CAK · cold climate22.3 SEER2 · 9.7 HSPF2

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

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 13, 2026. How we use the data.