What is the SEER2 rating of the Lennox MWHD024S6-1P?

The Lennox MWHD024S6-1P is rated at up to 20.0 SEER2 and 12.2 EER2 for cooling and up to 8.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.

Is the Lennox MWHD024S6-1P good for cold climates?

It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 24,000 BTU model.

How much does the Lennox MWHD024S6-1P cost to run per year?

At its rated efficiency it costs about $523-$1,797 a year in electricity in large U.S. cities, depending on climate and local rates - for example $700 in Phoenix and $1,543 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

Is the Lennox MWHD024S6-1P the same as the Lennox MWHD024S6S-1P?

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 MWHD024S6-1P?

ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses LENNOX MWHD024S6S-1P.

24,000 BTU mini-split heat pump · WindFree - Standard (RAC)

Lennox MWHD024S6-1P

Below average cooling and heating efficiency for a 24,000 BTU mini-split heat pump, but not rated for cold climates.

Ranks #358 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $713 a year to run in a mixed climate like Atlanta.

SEER2: 20.0 Cooling efficiency over a season
Below average · beats 18%
HSPF2: 8.0 Heating efficiency over a season
Below average · beats 0%
EER2: 12.2 Cooling efficiency on a 95°F day
Below average · beats 33%
Heat at 5°F: 17,300 BTU/h72% of its 47°F output
Below average · beats 32%

A good fit if…

You want steady temperatures and quiet running - the compressor varies its speed.

Think twice if…

You often see nights below 0°F - it is not cold-climate certified.
Cooling cost matters most - its SEER2 is below average for mini-splits.
You mainly need heat - its HSPF2 is below average for mini-splits.

Calculate my running cost

Details

Specifications24,000 BTU, R-32

General
Brand	Lennox
Outdoor unit model	MWHD024S6-1P
Series	WindFree - Standard (RAC)
Type	Mini-split heat pump
Nominal size	24,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-32
Connected (smart) capable	No
On the market since	July 23, 2024
Last certified	April 17, 2026
Cooling
SEER2Seasonal efficiency, higher is better	20.0 (range 20.0)
EER2Efficiency at 95°F outdoors	12.2
Cooling capacity	22,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	8.0
Capacity at 47°F	24,000 BTU/h
Capacity at 17°F	20,400 BTU/h
Capacity at 5°F	17,300 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	1.92
ENERGY STAR cold climate	No

Heating output as it gets colder72% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with MWHD024S6S-1P at the standard test temperatures, in BTU/h:

Certified matchups1 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.
MWHD024S6S-1P LENNOX	20.0	12.2	8.0	17,300	215810021

Same unit, other model numbers1

These model numbers have exactly the same certified ratings and matchups as the Lennox MWHD024S6-1P: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

Lennox MWHD024S6S-1P

Yearly running cost in 10 large cities$523-$1,797

Phoenix, AZ$700/yr
Miami, FL$523/yr
Houston, TX$630/yr
Atlanta, GA$713/yr
Los Angeles, CA$711/yr
New York, NY$1,797/yr
Chicago, IL$1,477/yr
Denver, CO$1,242/yr
Seattle, WA$775/yr
Minneapolis, MN$1,543/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 MWHD024S6-1P?: The Lennox MWHD024S6-1P is rated at up to 20.0 SEER2 and 12.2 EER2 for cooling and up to 8.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
Is the Lennox MWHD024S6-1P good for cold climates?: It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 24,000 BTU model.
How much does the Lennox MWHD024S6-1P cost to run per year?: At its rated efficiency it costs about $523-$1,797 a year in electricity in large U.S. cities, depending on climate and local rates - for example $700 in Phoenix and $1,543 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Is the Lennox MWHD024S6-1P the same as the Lennox MWHD024S6S-1P?: 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 MWHD024S6-1P?: ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses LENNOX MWHD024S6S-1P.
What refrigerant does the Lennox MWHD024S6-1P 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 $723/yrYou save $444/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 MWHD024S6-1P

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: $723
Current system, per year: $1,167
You save per year: $444
Payback: 19.1 years
Net after 10 years: -$4,061

Cooling $387Heating $336Electricity used: 4,520 kWhSaved vs. a minimum-efficiency heat pump: $177

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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Mitsubishi Electric SUZ-KA30NA219.9 SEER2 · 10.6 HSPF2
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See all 430 24,000 BTU mini-splits, ranked

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