MRCOOL® Olympus E Star® 4th Gen 18,000 BTU (1.5 Ton) Ductless Mini Split Heat Pump — O-ES-18-HP-C-230C-O1 + O-18-HP-WMAH-230C-O
Overview
The MRCOOL® Olympus E Star® 4th Gen 18k is a single-zone ductless mini split heat pump designed for professional HVAC installation. It pairs a wall-mounted air handler with a compact inverter-driven condenser for consistent comfort, quiet operation, and strong efficiency. Control is simple with the included remote and built-in Wi-Fi via the MRCOOL® Smart HVAC app, plus voice control compatibility with Amazon Alexa and Google Assistant. The outdoor unit features Gold Fin® corrosion protection and the system uses R-454B refrigerant.
Data provided includes two different SEER2 values for this size (23.5 and 21.4). This page uses the rating shown for the condenser pairing: Up to 21.4 SEER2.
Highlights
- Efficiency: Up to 21.4 SEER2 and up to 12.5 EER2 with inverter performance.
- Cold-climate capable: Outdoor operation listed down to -22°F for heating (and cooling).
- Gold Fin® condenser: Corrosion-resistant protection for harsh or coastal environments.
- Smart control included: Built-in Wi-Fi + Smart HVAC app; works with Alexa/Google Assistant.
- Comfort features: Sleep mode, louver memory, auto-restart, fan-only operation.
- Designed for pros: Professional installation required for optimal performance and warranty support.
501–750 sq ft*
18,000 / 18,000 BTU
98.4 ft
Outdoor 59 dB(A)
*Other fields list “Up to 800 sq ft.” Real coverage varies by climate, insulation, and room load.
What’s Included
- Outdoor Condenser: O-ES-18-HP-C-230C-O1
- Wall-Mounted Air Handler: O-18-HP-WMAH-230C-O
- SmartHVAC WiFi control (app + voice control supported)
- Remote control
- Installation and service documentation (see Documents & Downloads)
Indoor Specs
Model: O-18-HP-WMAH-230C-O (Wall-Mounted Air Handler)
| Brand / Series | MRCOOL • Olympus 4th Gen Air Handlers |
| Type | Mini-Split (Indoor Unit) |
| Max Coverage | Up to 800 sq ft |
| Indoor Noise (multi-speed) | 49.5 / 45 / 38 / 31.5 / 19.5 dB(A) |
| Speeds / Oscillation | 5 (Variable) • Oscillation: Yes |
| Refrigerant | R-454B |
| Line Set Fittings | Flare • Liquid 1/4" • Suction 1/2" |
| Electrical | 208–230V • 1-Phase • 60 Hz • Max Breaker 15A |
| Mount / Color | Wall • White |
| Filter | Reusable |
| Dimensions (W×D×H) | 40.31" × 9.69" × 12.64" |
| Weight | 27.34 lb |
| Control Options | Smart HVAC app • Remote included • Works with iOS/Android • Alexa/Google Assistant |
| Aux Heat | Not available on this air handler (no aux heater) |
| Restrictions | Restricted states: GU, PR, VI • Proposition 65: Yes |
Outdoor Specs
Model: O-ES-18-HP-C-230C-O1 (Single-Zone Condenser)
| Brand / Series | MRCOOL • Olympus 4th Gen Single-Zone Condensers |
| Cooling / Heating Capacity | 18,000 BTU / 18,000 BTU |
| Outdoor Temp Range (Cooling) | -22°F to 122°F |
| Outdoor Temp Range (Heating) | -22°F to 75°F |
| Efficiency | SEER2: Up to 21.4 • EER2: Up to 12.5 • HSPF2-4: 11 • HSPF2-5: 8.5 |
| Outdoor Noise | 59 dB(A) |
| Electrical | 208–230V • 1-Phase • 60 Hz • Max Breaker 20A • MCA 19A |
| Refrigerant | R-454B • 55.38 oz |
| Line Set | Flare • Liquid 1/4" • Suction 1/2" • Max length 98.4 ft |
| Inverter / Metering | DC inverter • Metering: EXV + Throttle Valve |
| Compressor | Rotary |
| Dimensions (W×D×H) | 35.04" × 13.46" × 26.5" |
| Weight | 99.87 lb |
| Certifications | ENERGY STAR® • UL Listed • CSA Listed • ETL Listed • AHRI Certified |
| Restrictions | Restricted states: GU, PR, VI • Proposition 65: Yes |
Documents & Downloads
Outdoor Condenser: O-ES-18-HP-C-230C-O1
- Brochure (EN)
- Installation Manual (EN)
- Service Manual (EN)
- Warranty (EN)
- AHRI Certificate
- Energy Guide
Indoor Air Handler: O-18-HP-WMAH-230C-O
Note: Some documents apply to the Olympus 4th Gen single-zone platform and may be shared across multiple sizes.
Important
- HVAC technician required: Installation by a licensed professional is required where applicable.
- Refrigerant and piping: R-454B refrigerant with flared connections (1/4" liquid, 1/2" suction).
- Line length: Max line set length is 98.4 ft. Longer runs can reduce performance and may require design adjustments.
- Electrical: Outdoor unit requires up to a 20A breaker (MCA 19A).
- Warranty basics: 5-year parts / 7-year compressor (with notes about extended coverage upon registration as provided).
FAQs
Is professional installation required?
Yes. This system is intended for installation by a licensed HVAC technician.
What size space does this cover?
Provided specs list coverage as 501–750 sq ft and also “up to 800 sq ft.” Actual results vary by climate and building load.
Does it support app and voice control?
Yes. Wi-Fi connectivity supports the MRCOOL Smart HVAC app and voice control via Amazon Alexa and Google Assistant.
What line sizes does it use?
Flared connections with 1/4" liquid and 1/2" suction lines.
What electrical circuit is required?
208–230V, 1-phase, 60 Hz. Outdoor unit: 20A max breaker and 19A MCA.
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We will prepare your order within 24 hours if it’s received on a weekday (before noon). Orders are shipped in one to two business days. Transit time is between 3 to 6 business days, although exceptions apply. We email tracking information once your purchase is shipped.
Delivery Map
IMPORTANT DELIVERY INFORMATION: Please be kindly informed that this air conditioner, due to its weight and shipping restrictions, is shipped palletized with an arranged freight service and requires an appointment for delivery. To AVOID delays, please check if the provided phone number in the order details is a current number where you can be reached. You can also contact the carrier directly and refer to your tracking number to set up a date and time for your appointment. It is your responsibility to ensure a safe and secure environment for delivery. Please note that we cannot be held liable for any packages that are stolen or lost after delivery has been confirmed. PLEASE verify your shipping address, as changes to the address after freight has shipped can result in an additional 15% or higher fee depending on freight weight and dimensions.
SMALLWARES INFORMATION: Please be informed that for smaller items, such as Installation Kits, Smart Connectivity Dongles, and TTW Sleeves, when these items are ordered individually, they may be shipped via FedEx without a signature requirement. It is your responsibility to ensure a safe and secure environment for delivery. Please note that we cannot be held liable for any packages that are stolen or lost after delivery has been confirmed. Thank you for your understanding and cooperation.
INSPECT YOUR MERCHANDISE BEFORE SIGNING: Please inspect your boxes thoroughly when you receive them. They should arrive shrink-wrapped and on a pallet. If you notice any damages or imperfections (e.g. crushed box or forklift hole), please write comments on the receipt before signing for delivery, no matter how small damages seem. Contact us immediately to assist you.
Shipping & Delivery
We will prepare your order within 24–48 hours if it’s received on a weekday (before noon). Orders are shipped in one to two business days. Transit time is between 3 to 6 business days, although exceptions apply. We email tracking information once your purchase is shipped.
Delivery Map
IMPORTANT DELIVERY INFORMATION
Please be informed that this air conditioner, due to its weight and shipping restrictions, is shipped palletized with an arranged freight service and requires an appointment for delivery.
To AVOID delays, please make sure the phone number in your order details is accurate and one where you can be reached. You may also contact the carrier directly using your tracking number to schedule your delivery.
It is your responsibility to ensure a safe and secure delivery environment. We are not liable for any packages that are stolen or lost after delivery is confirmed.
Please verify your shipping address carefully. Changes to your shipping address after the freight has been shipped may result in additional fees of 15% or more, depending on freight weight and dimensions.
SMALLWARES INFORMATION
Smaller items such as Installation Kits, Smart Connectivity Dongles, and TTW Sleeves may be shipped via FedEx without a signature requirement if ordered individually.
It is your responsibility to ensure a safe delivery location. We are not liable for packages lost or stolen after delivery confirmation. Thank you for your understanding and cooperation.
INSPECT YOUR MERCHANDISE BEFORE SIGNING
Please inspect your boxes carefully upon delivery. Shipments should arrive shrink-wrapped and on a pallet. If you notice any damage or signs of mishandling (such as a crushed box or forklift puncture), write comments on the delivery receipt before signing, even if the damage appears minor.
Contact us immediately if any issues arise so we can assist you promptly.
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