HVAC Rated

24,000 BTU mini-split heat pump · O-series

TRUST AIR CONDITIONERS OAH24H/O4S4P

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

Ranks #237 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $582 a year to run in a mixed climate like Atlanta.

SEER2
21.5 Cooling efficiency over a season
Below average · beats 39%
HSPF2
11.4 Heating efficiency over a season
Very good · beats 82%
EER2
13.0 Cooling efficiency on a 95°F day
Average · beats 62%
Heat at 5°F
27,000 BTU/h86% 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 27,000 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…

  • 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
BrandTRUST AIR CONDITIONERS
Outdoor unit modelOAH24H/O4S4P
SeriesO-series
TypeMini-split heat pump
Nominal size24,000 BTU
CompressorVariable-speed units run longer at low powerContinuously variable
RefrigerantR-410A
Connected (smart) capableNo
On the market sinceOctober 14, 2022
Last certifiedJune 25, 2026
Cooling
SEER2Seasonal efficiency, higher is better21.5 (range 19.2-21.5)
EER2Efficiency at 95°F outdoors11.7-13.0
Cooling capacity24,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better10.5-11.4
Capacity at 47°F25,000-29,000 BTU/h
Capacity at 17°F19,000-21,200 BTU/h
Capacity at 5°F25,000-27,000 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater2.00-2.21
ENERGY STAR cold climateYes
Heating output as it gets colder86% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with IUMW124H/I41P at the standard test temperatures, in BTU/h:

Certified matchups4 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 unitSEER2EER2HSPF2Heat @5°FAHRI ref.
IUMW124H/I41P · cold climate21.513.011.425,000208816917
IUMFC24H/I41P · cold climate20.511.711.025,000208816939
IUMFC24H/I41P · cold climate20.511.711.025,000208816939
IUMDL24H/I43P · cold climate19.212.010.527,000208816933
Yearly running cost in 10 large cities$524-$1,389

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

Questions5
What is the SEER2 rating of the TRUST AIR CONDITIONERS OAH24H/O4S4P?
The TRUST AIR CONDITIONERS OAH24H/O4S4P is rated at up to 21.5 SEER2 and 13.0 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 4 certified matchups SEER2 ranges from 19.2-21.5.
Is the TRUST AIR CONDITIONERS OAH24H/O4S4P good for cold climates?
Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 27,000 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 TRUST AIR CONDITIONERS OAH24H/O4S4P cost to run per year?
At its rated efficiency it costs about $524-$1,389 a year in electricity in large U.S. cities, depending on climate and local rates - for example $645 in Phoenix and $1,159 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 TRUST AIR CONDITIONERS OAH24H/O4S4P?
ENERGY STAR lists 4 certified combinations for this outdoor unit. The highest-rated ones use IUMW124H/I41P, IUMFC24H/I41P, IUMDL24H/I43P.
What refrigerant does the TRUST AIR CONDITIONERS OAH24H/O4S4P 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 $639/yrYou save $615/yrSee details ↓
1. Where you live
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.

2. The heat pump TRUST AIR CONDITIONERS OAH24H/O4S4P
3. What it replaces
4. Price replace the example with your quote
Heat pump, per year
$639
Current system, per year
$1,254
You save per year
$615
Payback
14.6 years
Net after 10 years
-$2,847

Cooling $393Heating $246Electricity used: 3,991 kWhSaved vs. a minimum-efficiency heat pump: $326

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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Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 25, 2026. How we use the data.