MRCOOL Olympus 4th Generation 3-Zone Ductless Mini Split AC & Heat Pump 36000 BTU (9K+12K+24K), Wall Mount Units, 230V
Premium performance for up to six zones with advanced inverter efficiency, SmartHVAC control, and durable Gold Fin® protection.
Overview
The Olympus Multi-Zone 4th Gen is built for whole-home flexibility—one outdoor condenser can support multiple indoor zones for independent room comfort. Note: multi-zone systems run in one mode at a time (the system heats or cools as a whole).
MULTI5-36HP230C-O + O-09-HP-WMAH-230C-O + O-12-HP-WMAH-230C-O + O-24-HP-WMAH-230C-O
MULTI5-36HP230C-O
30.5
35
Why Homeowners Love It
- Your comfort, multiplied: Multi-zone technology gives room-by-room temperature control in up to six zones.
- Premium efficiency: Advanced inverter performance helps reduce monthly heating and cooling costs.
- All-season reliability: Dependable low-ambient operation and stable comfort in changing outdoor conditions.
- Smart control: Set schedules, adjust setpoints, and manage zones from the SmartHVAC app (plus Alexa/Google voice).
- Built to last: Gold Fin® condenser protection improves corrosion resistance—ideal for harsh or coastal regions.
Important: This system is not marketed as DIY—professional installation is required.
What’s Included
- (1) Outdoor condenser: MULTI5-36HP230C-O
- Indoor wall mounts:
- 9,000 BTU (x1) — Model: O-09-HP-WMAH-230C-O
- 12,000 BTU (x1) — Model: O-12-HP-WMAH-230C-O
- 24,000 BTU (x1) — Model: O-24-HP-WMAH-230C-O
- Zone remotes/controllers (model-specific)
- Refrigerant line sets & interconnect/communication wiring (must be selected in the options to be included; choose the appropriate length for each indoor unit based on your layout)
- Mounting hardware for indoor units
- Installation documentation (see Documents & Downloads)
Mrcool DIY Multi-Zones
Key Features
- Advanced inverter technology: High efficiency and stable comfort with variable-speed performance.
- Low-ambient cooling: Designed for applications that may require cooling in colder weather (e.g., server rooms / greenhouses).
- Refrigerant leak detection: Built-in monitoring with fault indication to help protect the system.
- Gold Fin® condenser: Added corrosion resistance for long-term durability.
- SmartHVAC control: App scheduling + remote access, plus Alexa/Google voice integration.
- Comfort features: Sleep mode, auto restart, and diagnostic codes (model-specific).
R-454B is an A2L refrigerant. Installation/service must follow the manufacturer manual and applicable codes.
Comfort Modes
- Auto: Automatically selects heating or cooling to maintain setpoint.
- Cool / Heat: Dedicated modes for seasonal comfort.
- Dry: Dehumidifies while maintaining comfort.
- Sleep: Energy-saving overnight profile.
- Timer: Scheduled on/off for efficiency.
Multi-zone systems operate in one mode at a time—you can’t heat one room while cooling another.
Warranty
Standard coverage commonly includes a 7-year compressor warranty and a 5-year parts warranty (registration requirements apply).
Extended limited lifetime replacement coverage may require enrollment in the MRCOOL® Care Kit program and additional conditions/fees.
Indoor Specs
| brand name | MRCOOL |
|---|---|
| series | Olympus 4th Gen Air Handlers |
| model | O-12-HP-WMAH-230C-O |
| unit type | Mini-Split |
| short description | Olympus 12,000 BTU 1 Ton Ductless Mini-Split Wall Mounted Air Handler - 230V/60Hz |
| long description | Experience dependable heating and cooling with the MRCOOL® OLYMPUS ESTAR® 12k Series air handler, designed for spaces up to 550 square feet—perfect for bedrooms, home offices, garages, and more. Its compact design makes installation quick and hassle-free for your technician. Stay in control from anywhere with the MRCOOL® Smart HVAC app, which connects via Wi-Fi to your smartphone or tablet. Prefer a more hands-on approach? Use the included remote control for simple and convenient operation. Engineered for energy efficiency, this unit delivers strong performance with a SEER2 rating of 25.5, EER2 of 13, and HSPF2-4 of 10.6—helping you reduce energy consumption and save on utility costs. A variety of indoor fan speeds ensures optimal comfort, while its whisper-quiet operation at just 46 dB keeps noise to a minimum. Now using R-454B refrigerant, an environmentally friendly option, this system supports a greener future without compromising performance. Enjoy multiple control options, including wireless remote access, the smartHVAC app, and voice control compatibility with Amazon Alexa and Google Assistant—giving you the flexibility to adjust your comfort your way. Backed by an industry-leading warranty, including a limited lifetime warranty, 7-year compressor coverage, and a 5-year parts warranty, the MRCOOL® OLYMPUS ESTAR® 12k Series offers advanced features, quiet operation, and year-round comfort you can count on. |
| works with | O-ES-12-HP-C-230C-O1 MULTI3-18HP230C-O MULTI4-27HP230C-O MULTI5-36HP230C-O MULTI6-48HP230C-O |
| tonnage | 1.0 |
| voltage (v) | 208/230 |
| phase | 1 |
| cycle (hz) | 60 |
| max fuse breaker (a) | 15 |
| min circuit ampacity (a) | 3.0 |
| mount type | Wall |
| color | White |
| max coverage area | Up to 550 |
| refrigerant type | R-454B |
| decibel rating (dba) | 47/36.5/32.5/22/19.5 |
| decibel rating low (dba) | 19.5 |
| decibel rating high (dba) | 47.0 |
| number of speeds | 5 (Variable) |
| oscillation | Yes |
| lineset fitting type | Flare |
| liquid line size | 1/4 |
| suction line size | 3/8 |
| blower motor speeds | 441.4/323.7/229.6/176.6/147.2 |
| blower motor rpm | 1100/850/700 |
| filter type | Reusable |
| auxiliary heater included | No |
| auxiliary heater available | No |
| fan only option | Yes |
| sleep mode | Yes |
| auto cool | Yes |
| wifi compatibility | Yes |
| app compatibility | Yes |
| works with ios | Yes |
| works with android | Yes |
| remote control included | Yes |
| ul listed | Yes |
| csa listed | Yes |
| etl listed | Yes |
| base warranty | 5-Year Parts |
| base parts warranty | 5-Year |
| base remote warranty | 5 Year |
| registered labor warranty | None |
| base labor warranty | None |
| has batteries | Yes |
| contains electronics | Yes |
| contains chemicals | Yes |
| contains compressed gas | Yes |
| proposition 65 warning | Yes |
| restricted states | GU, PR, VI |
| net depth (in) | 9.09 |
| net height (in) | 11.81 |
| net width (in) | 33.74 |
| net weight | 22.93 |
| gross depth (in) | 12.2 |
| gross height (in) | 14.57 |
| gross width (in) | 36.22 |
| gross weight (lbs) | 29.32 |
Outdoor Specs
Helpful Notes
Professional installation required
Installation must be completed by a qualified HVAC professional. Improper installation can cause water leakage, electrical shock, or fire.
Mixing indoor unit types
Many Olympus multi-zone configurations allow mixing compatible indoor styles (wall mounts, ceiling cassettes, and concealed duct models). Confirm compatibility for your condenser model before ordering.
Line sets & wiring (options)
Line sets and communication wiring may be bundled depending on your selected options. If no installation kit is selected, they may not be included. Select the appropriate length for each indoor unit based on your layout.
Electrical & breaker sizing
Use MCA (30.5) and Max Fuse/Breaker (35) as starting points, then size per the installation manual and local code.
Line sizing
Indoor line sizes: 1/4 / 3/8 | 3/8 / 5/8. Confirm final line sizes, allowable lengths, and any additional charge requirements for your exact pairing before selecting line sets.
