What's in this package
Every piece below is included in your system price — matched to optimize efficiency, power and compatibility. Tap a piece to see its full description, specs and manuals.
The MRCOOL® Olympus MULTI3-18HP230C-O is a high-performance 18,000 BTU multi-zone heat pump condenser designed to power up to three indoor units simultaneously. Perfect for homeowners looking to efficiently manage temperatures in multiple spaces, this ductless system offers individualized climate control for each connected zone, making it a flexible solution for modern living environments. Built with advanced inverter technology, the unit delivers impressive efficiency, with SEER2 ratings up to 25.1 and HSPF2-4 up to 10. It performs reliably in diverse conditions, operating in outdoor temperatures as low as 5°F, ensuring comfort in both summer and winter months. This model is compatible with various
MRCOOL indoor units, including wall-mounted, ceiling cassette, and concealed duct options, giving users the freedom to tailor the system to their home’s layout and aesthetics. Smart features elevate user convenience, with control options that include the MRCOOL SmartHVAC app, traditional remotes, or even voice commands via Amazon Alexa and Google Assistant. Additional functions such as sleep mode, auto restart, and refrigerant leak detection contribute to enhanced safety and comfort. Backed by a 7-year warranty on the compressor and 5 years on parts (with professional installation), the MRCOOL®Olympus MULTI3-18HP230C-O is a reliable and energy-efficient choice for those seeking customized, zone-specific heating and cooling.
Features
- Installation by a licensed professional required where applicable 7-Year Compresser, 5-Year Parts warranty when registered and installed by a licensed professional R-454B environmentally friendly refrigerant Energy Star Certified
Works With
- O-09-HP-WMAH-230C-O
- DUCT-09HP-230B-O
- CASSETTE09HP-230C-O
- O-12-HP-WMAH-230C-O
- DUCT-09HP-230B-O
- CASSETTE12HP-230C-O
- Net Dimensions (In)
- 13.46 D x 26.5 H x 35.04 W
- Net Weight (Lbs)
- 100.53
- Gross Depth (In)
- 17.24
- Gross Height (In)
- 29.53
- Gross Width (In)
- 40.55
- Gross Weight (Lbs)
- 109.35
- Color
- White
- Max Coverage Area
- Up to 750
- Inverter
- DC
- Metering Device
- EXV + Capillary
- SEER2
- Up to 25.1
- EER2
- Up to 14
- HSPF2-4
- 9.8
- HSPF2-5
- 7.8
- Tonnage
- 1.5
- Cooling Capacity (Btu)
- 18000
- Heating Capacity (Btu)
- 19000
- Cycle
- 60
- Zone Capacity
- 3
- Compressor Motor Type
- Twin-Rotary
- Condenser Fan Motor Rpm
- 750/600/500
- Decibel Rating (Dba)
- 59.5
- Voltage (V)
- 208/230
- Phase
- 1
- Max Fuse Breaker (A)
- 20
- Min Circuit Ampacity (A)
- 16
- Refrigerant Type
- R-454B
- Refrigerant Volume (Oz)
- 61.73
- Max Lineset Length (Ft)
- 196.8 total
- Lineset Fitting Type
- Flare
- Liquid Line Size
- 3 x 1/4
- Suction Line Size
- 3 x 3/8
- UL Listed
- Yes
- CSA Listed
- Yes
- ETL Listed
- Yes
- Energy Star Certified
- Yes
- AHRI Certified
- Yes
- Has Batteries
- Yes
- Contains Electronics
- Yes
- Contains Chemicals
- Yes
- Contains Compressed Gas
- Yes
- Proposition 65 Warning
- Yes
- Restricted States
- GU, PR, VI
- Base Warranty
- 5-Year Parts/7-Year Compressor
- Base Parts Warranty
- 5-Year
- Base Compressor Warranty
- 7-Year
- Base Remote Warranty
- 5 Year
- Registered Labor Warranty
- None
- Base Labor Warranty
- None
The MRCOOL® OLYMPUS 9K CASSETTE provides dependable heating and cooling for spaces up to 400 square feet, making it perfect for bedrooms, home offices, and smaller areas. Designed to fit seamlessly into the ceiling for a flush look, it almost disappears, creating a clean, modern aesthetic that complements any room style. Its versatile design is perfect for homes or businesses looking to maximize space while maintaining an elegant, high-performance climate solution. The indoor fan operates at a quiet 42 dB, ensuring a peaceful environment without compromising performance. This ultra-low noise level means you can enjoy consistent, efficient heating or cooling without disruptive fan sounds, ideal for spaces where silence is crucial, like bedrooms, offices, or nurseries. The quiet operation helps enhance the overall comfort of your space, providing a relaxing atmosphere free from distractions.
The unit uses R-454B refrigerant, an eco-friendly solution that provides top-tier performance while being environmentally responsible. With low global warming potential, R-454B helps reduce the environmental impact of your system, contributing to a greener, more sustainable home, without sacrificing performance or efficiency. This refrigerant is an important choice for homeowners seeking to lower their carbon footprint while still enjoying reliable performance.
The MRCOOL® OLYMPUS 9K CASSETTE comes with a limited lifetime warranty, 7-year compressor coverage, and a 5-year parts warranty, ensuring reliability, cutting-edge technology, and peace of mind. This unit is the ideal solution for homeowners who value efficiency, comfort, and modern design.
Works With
- O-ES-09-HP-C-230C-O1
- MULTI3-18HP230C-O
- MULTI4-27HP230C-O
- MULTI5-36HP230C-O
- MULTI6-48HP230C-O
- Net Dimensions (In)
- 22.44 D x 9.65 H x 22.44 W
- Net Weight (Lbs)
- 35.27
- Gross Weight (Lbs)
- 41.89
- Mount Type
- Ceiling
- Color
- White
- Max Coverage Area
- Up to 400
- Air Flow Direction
- Downflow
- Number Of Speeds
- 5 (Variable)
- Oscillation
- Yes
- Tonnage
- 0.75
- Cycle
- 60
- Blower Motor Speeds
- 353.2/312/264.9/182.5/147.2
- Blower Motor Rpm
- 600/530/380
- Decibel Rating (Dba)
- 42.5/40/37.5/26/24
- Decibel Rating Low (Dba)
- 24
- Decibel Rating High (Dba)
- 42.5
- Voltage (V)
- 208/230
- Phase
- 1
- Max Fuse Breaker (A)
- 15
- Min Circuit Ampacity (A)
- 3
- Refrigerant Type
- R-454B
- Lineset Fitting Type
- Flare
- Liquid Line Size
- 4-Jan
- Suction Line Size
- 8-Mar
- Filter Type
- Reusable
- Auxiliary Heater Included
- No
- Auxiliary Heater Available
- No
- Fan Only Option
- Yes
- Sleep Mode
- Yes
- Auto Cool
- Yes
- Wifi Compatibility
- No
- App Compatibility
- No
- Works With Ios
- No
- Works With Android
- No
- Remote Control Included
- Yes
- UL Listed
- Yes
- CSA Listed
- Yes
- ETL Listed
- Yes
- Has Batteries
- Yes
- Contains Electronics
- Yes
- Contains Chemicals
- Yes
- Contains Compressed Gas
- Yes
- Proposition 65 Warning
- Yes
- Restricted States
- GU, PR, VI
- Base Warranty
- 5-Year Parts
- Base Parts Warranty
- 5-Year
- Base Remote Warranty
- 5 Year
- Registered Labor Warranty
- None
- Base Labor Warranty
- None
MRCOOL Mini Split BTU Guide
Drawn to scale — 1 square = 2 × 2 ftThis system’s condenser supports up to 18K BTU connected. Toggle zones to see how your mix loads it — MRCOOL allows connecting more than 100% because zones rarely all run at max.








