What is the SEER2 rating of the Lennox MMLD009S6S-1P?

The Lennox MMLD009S6S-1P is rated at up to 22.1 SEER2 and 13.8 EER2 for cooling and up to 10.6 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 5 certified matchups SEER2 ranges from 18.9-22.1.

Is the Lennox MMLD009S6S-1P good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 9,600 BTU/h at 5°F with a COP of 1.80, so it is still 1.8 times as efficient as electric resistance heat at that temperature.

How much does the Lennox MMLD009S6S-1P cost to run per year?

At its rated efficiency it costs about $194-$676 a year in electricity in large U.S. cities, depending on climate and local rates - for example $261 in Phoenix and $582 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

Is the Lennox MMLD009S6S-1P the same as the Samsung AC009DXSCCG?

Yes, as far as the certified ratings go. ENERGY STAR lists both model numbers with identical efficiency, capacity and matchups, which means the same outdoor unit sold under a different brand or with a minor variant code (voltage, colour or region). The full list is on this page.

Which indoor units work with the Lennox MMLD009S6S-1P?

ENERGY STAR lists 5 certified combinations for this outdoor unit. The highest-rated ones use LENNOX M1WD009S6-1P, LENNOX M22D009S6-1P, LENNOX MFMD009S6-1P.

9,000 BTU mini-split heat pump · 1-Way Cassette (WindFree™) Premium (CAC)

Lennox MMLD009S6S-1P

Average cooling and heating efficiency for a 9,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #254 of 395 9,000 BTU mini-splits for cooling efficiency, and costs about $267 a year to run in a mixed climate like Atlanta.

SEER2: 22.1 Cooling efficiency over a season
Average · beats 51%
HSPF2: 10.6 Heating efficiency over a season
Average · beats 65%
EER2: 13.8 Cooling efficiency on a 95°F day
Very good · beats 79%
Heat at 5°F: 9,600 BTU/h80% of its 47°F output
Below average · beats 9%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 9,600 BTU/h at 5°F.
You want steady temperatures and quiet running - the compressor varies its speed.

Think twice if…

Nothing stands out - its ratings have no weak spot for its class.

Calculate my running cost

Details

Specifications9,000 BTU, R-32

General
Brand	Lennox
Also sold as	Samsung
Outdoor unit model	MMLD009S6S-1P
Series	1-Way Cassette (WindFree™) Premium (CAC)
Type	Mini-split heat pump
Nominal size	9,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-32
Connected (smart) capable	No
On the market since	December 11, 2024
Last certified	May 13, 2026
Cooling
SEER2Seasonal efficiency, higher is better	22.1 (range 18.9-22.1)
EER2Efficiency at 95°F outdoors	12.7-14.0
Cooling capacity	9,000-9,100 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	9.5-10.6
Capacity at 47°F	10,000-12,000 BTU/h
Capacity at 17°F	8,000-9,700 BTU/h
Capacity at 5°F	8,000-9,600 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	1.80
ENERGY STAR cold climate	Yes

Heating output as it gets colder80% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with M1WD009S6-1P at the standard test temperatures, in BTU/h:

Certified matchups5 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.
M1WD009S6-1P LENNOX · cold climate	22.1	13.8	9.5	9,600	216581320
M22D009S6-1P LENNOX · cold climate	22.0	14.0	10.6	8,000	216581326
MFMD009S6-1P LENNOX · cold climate	21.0	12.7	9.7	8,100	216581328
MMDD009S6-1P LENNOX · cold climate	20.1	13.5	9.6	9,600	216581322
MDDD009S6-1P LENNOX · cold climate	18.9	12.7	10.0	9,600	216581324

Same unit, other model numbers1

These model numbers have exactly the same certified ratings and matchups as the Lennox MMLD009S6S-1P: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

Samsung AC009DXSCCG

Yearly running cost in 10 large cities$194-$676

Phoenix, AZ$261/yr
Miami, FL$194/yr
Houston, TX$235/yr
Atlanta, GA$267/yr
Los Angeles, CA$267/yr
New York, NY$676/yr
Chicago, IL$556/yr
Denver, CO$468/yr
Seattle, WA$292/yr
Minneapolis, MN$582/yr

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

Questions6

What is the SEER2 rating of the Lennox MMLD009S6S-1P?: The Lennox MMLD009S6S-1P is rated at up to 22.1 SEER2 and 13.8 EER2 for cooling and up to 10.6 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 5 certified matchups SEER2 ranges from 18.9-22.1.
Is the Lennox MMLD009S6S-1P good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 9,600 BTU/h at 5°F with a COP of 1.80, so it is still 1.8 times as efficient as electric resistance heat at that temperature.
How much does the Lennox MMLD009S6S-1P cost to run per year?: At its rated efficiency it costs about $194-$676 a year in electricity in large U.S. cities, depending on climate and local rates - for example $261 in Phoenix and $582 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Is the Lennox MMLD009S6S-1P the same as the Samsung AC009DXSCCG?: Yes, as far as the certified ratings go. ENERGY STAR lists both model numbers with identical efficiency, capacity and matchups, which means the same outdoor unit sold under a different brand or with a minor variant code (voltage, colour or region). The full list is on this page.
Which indoor units work with the Lennox MMLD009S6S-1P?: ENERGY STAR lists 5 certified combinations for this outdoor unit. The highest-rated ones use LENNOX M1WD009S6-1P, LENNOX M22D009S6-1P, LENNOX MFMD009S6-1P.
What refrigerant does the Lennox MMLD009S6S-1P 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 $270/yrYou save $243/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 Lennox MMLD009S6S-1P

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: $270
Current system, per year: $513
You save per year: $243
Payback: 14.4 years
Net after 10 years: -$1,070

Cooling $143Heating $127Electricity used: 1,688 kWhSaved vs. a minimum-efficiency heat pump: $131

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.

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See all 395 9,000 BTU mini-splits, ranked

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