OLMO Sierra 18,000 BTU Single Zone Wall Mount, 230V, R32 - Ductless Mini Split Air Conditioner Heat Pump | FACTORY

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OS-SR18-230VO/OS-A18SRW-230VI-16FT
Product specifications
Brand Olmo
Voltage 230V
SEER 21
WiFi Included
Zone Single Zone
Type Wall Mount
Freon R32
Compressor Inverter
$979.66 $911.08 Save 7% Sold out
Shipping Policy calculated at checkout.
Installation Kit: Factory 16ft

Every system includes a 16 ft installation kit inside the factory box. Selecting 25 ft or 50 ft orders a separate, longer kit — it does not replace the included 16 ft kit.

FREE Delivery
Out of stock right now We email you the ship date as soon as it lands. For the next arrival call (855) 775-4822.

Please note that all delivery dates and estimated transit times are approximate and are not guaranteed. Delivery times may vary due to carrier delays, weather, holidays, peak shipping periods, or other circumstances beyond our control. How delivery dates are calculated

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Questions about this system?

Answers in seconds — tap a question below

  • Sized for about 500–800 sq ft. Rule of thumb: ~20 BTU per sq ft, and 12,000 BTU = 1 ton (this unit is 18,000 BTU (1.5-ton)). Ceiling height, insulation, sun and climate shift that — if you're between sizes, size up for hot/humid rooms. Not sure? We'll confirm the right BTU for your space.
  • 12,000 BTU = 1 ton — "tons" is just the older way of stating capacity. So 24,000 BTU = 2 tons, 36,000 = 3 tons, and so on. This system is 18,000 BTU (1.5-ton). BTU tells you the capacity; SEER2 tells you the efficiency.
  • It uses R32 — an efficient, lower-GWP refrigerant that's now the industry standard on modern mini splits. The outdoor unit ships pre-charged for a standard line set, so most installs need no extra refrigerant; your licensed, EPA-608-certified installer verifies the charge and tops it off if your line set is longer.
  • Rated SEER2 21.0 — a strong efficiency number, and the higher it is the lower your energy bills. Its inverter compressor ramps up and down instead of cycling on/off, so it holds the temperature steadily, runs quietly, and uses less power than a standard AC or window unit.
  • Needs a dedicated 230V circuit, like a large household appliance, so it can deliver full capacity to larger rooms and multi-zone setups. Your licensed HVAC installer or electrician sets up the correct breaker and disconnect to meet local electrical code.
  • Yes — a big upgrade. It's far more efficient (inverter, SEER2 21.0) and much quieter, since the compressor sits outside instead of in your window or on the floor. It mounts permanently, doesn't block a window, and heats as well as cools year-round. Higher upfront cost, but lower bills and a longer lifespan.
  • Yes to all three. It's an inverter heat pump — cools in summer, heats in winter (even in the cold), far more efficiently than electric heaters. A Dry mode also pulls out humidity, so rooms feel cooler and less muggy.
  • Yes — WiFi is included, so you can set schedules, change the temperature, and even turn it on before you get home, all from the mobile app (and pair it with voice assistants). A standard remote is included too.
  • Ships as a complete set: OS-SR18-230VO, OS-18SRW-230VI. Everything arrives together — check the photos and specs for the full kit.
  • It should be installed by a licensed, EPA-608-certified HVAC professional — we don't recommend DIY installation. Handling refrigerant requires EPA Section 608 certification under U.S. law, and professional installation keeps the system safe, code-compliant, and your manufacturer warranty valid.
  • Yes — you get full inverter heat-pump technology and the same core features as premium brands without paying for the name, which is how we keep prices low. Shipping is free on U.S. orders over $300, and our team can help with sizing and support.
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Why buy this mini split from MiniSplitsForLess

  • Free Shipping over $300Ships free to the lower 48 states — flat rate, no surprises at checkout.
  • USA-Based Expert SupportReal U.S. HVAC pros help with BTU sizing, refrigerant and install questions.
  • Genuine Units & Full WarrantyBrand-new, authorized-dealer equipment backed by the full manufacturer warranty.
  • Fast Nationwide ShippingIn stock and ready to ship from U.S. warehouses across all 48 states.

What Stands Out

Sleek Wall-Mount Design

A slim, quiet indoor head mounts high on the wall and delivers 18000 BTU of heating & cooling — modern looks with whisper-quiet operation.

Inverter Efficiency — SEER2 21

A variable-speed inverter compressor ramps to match the load instead of cycling on/off, holding SEER2 21 on 230V — steady comfort with noticeably lower energy bills.

Right-Sized Coverage

Engineered to heat & cool up to 500–800 sq ft — matched capacity so you never over- or under-size the space.

Sierra Wall Mount

OLMO's Single-Zone Sierra Series is a versatile HVAC solution designed to provide efficient heating and cooling for multiple rooms. Equipped with advanced inverter technology, these units deliver precise temperature control and significant energy savings. Using eco-friendly R32 refrigerant, the system ensures reliable performance with minimal environmental impact. Perfect for residential or commercial applications, the Sierra Series offers quiet operation, flexible installation, and user-friendly controls, making it an ideal choice for maintaining year-round comfort across multiple zones with one efficient system.

White single-zone sierra air conditioner with purple shield logo and network background design.

Warranty and Tech Support Info

By selecting OLMO products for your home or business, you’ll receive expert technical support from heating and cooling specialist, including access to product manuals, troubleshooting guides and warranty information.

The manufacturer provides a Limited Warranty of 5 years for the compressor and 2 years for parts.

Warranty terms
Gray sectional sofa with yellow cushions and patterned throw, modern design.

Main Features

OLMO's Single-Zone Sierra Series delivers efficient multi-room comfort with advanced inverter technology for precise temperature control. Its eco-friendly R32 refrigerant reduces environmental impact, while quiet operation ensures minimal disruption. With flexible installation options, sleek design, and reliable heating and cooling, it’s the perfect solution for modern multi-zone climate control needs.

All Accessories Included

With your purchase, you receive a comprehensive MiniSplit system. MiniSplits4Less ensures you have everything needed for a seamless installation. Your package includes an Indoor Unit, Outdoor Unit, Remote Control, Manuals, a 16ft Line Set, and a Smartkit (WIFI). We've meticulously thought of every detail to provide you with all the essentials for your installation.

Technical Specifications

Indoor Unit Specs

Indoor Unit Specs — OS-18SRW-230VI
ModelOS-18SRW-230VI
Net/Gross Weight30.9/37.5 lb
Power Supply208-230V, 1Ph, 60Hz
Maximum Fuse Size20 A
Min. Circuit Ampacity14.5 A
Copper Line Size (Liquid/Gas)1/4"/1/2"
Noise Level (Hi/Med/Lo)48/45/41/39 dB
Airflow (Turbo/Hi/Mi/Lo)647/647/588/482/382 CFM
Dehumidification3.8 pt/h
Drain Pipe Diameter3/4"
ControllerL1-12

Outdoor Unit Specs

Outdoor Unit Specs — OS-SR18-230VO
ModelOS-SR18-230VO
Net/Gross Weight75/82.7 lb
Power Supply208-230V, 1Ph, 60Hz
Maximum Fuse Size20 A
Min. Circuit Ampacity14.5 A
Copper Line Size (Liquid/Gas)1/4"/1/2"
Noise Level56 dB
Airflow1,294 CFM
Dehumidification3.80 pt/h

System Specs

System Specs
Cooling Capacity 18,000 BTU
SEER2 21
Zones 1
Voltage 230V
Refrigerant Type R32
Copper Line Length 16.4 ft
Compressor Inverter
WiFi Included
Heating Capacity18,000 (6,500~19,000) BTU/h
Cooling Capacity Range18,000 (6,500~19,000) BTU/h
Max. Pipe Length98.4 ft
Refrigerant Precharge24.6 ft
Max Height Difference49.2 ft
COP3.91

Series Comparison Table

Technical specifications for every model in the Sierra series — this product is one of them.

Indoor Model OS-A09SRW-115VI OS-A12SRW-115VI OS-A09SRW-230VI OS-A12SRW-230VI OS-A18SRW-230VI OS-A24SRW-230VI OS-R36SRW-230VI
Outdoor Model OS-SR09-115VO OS-SR12-115VO OS-SR09-230VO OS-SR12-230VO OS-SR18-230VO OS-SR24-230VO OS-RSR36-230VO
Power Supply 115V-1Ph-60 115V-1Ph-60 208/230V-1Ph-60 208/230V-1Ph-60 208/230V-1Ph-60 208/230V-1Ph-60 208/230V-1Ph-60
Capacity 9000 12000 9000 12000 18000 24000 34500
Cooling
EER2 12.5 10.2 12.95 11.1 11.95 10.6 9.4
SEER2 20.0 18.0 22.5 20.0 21.0 19.5 20.0
Rated Capacity 9500 12000 9000 12000 18000 24000 35000
Heating
HSPF4 9.0 8.5 8.5 8.5 9.8 8.5 8.4
HSPF5 7.0 8.0 8.0 8.0 9.0 8.0 8.2
COP2 4.1 3.4 4.12 3.5 3.91 3.3 3.2
Minimum Circuit Ampacity 14.6 15.6 9.5 9.5 14.5 21 26.8
Max Fuse 25 25 15 15 20 35 35
Indoor Air Flow (Turbo/Hi/Mi/Lo/Si) 353/382/341/294/247 365/394/365/312/253 353/382/341/294/247 365/394/365/312/253 647/647/588/482/382 706/706/647/559/441 706/706/647/559/441/647
Indoor Noise Level (Turbo/Hi/Mi/Lo) 42/39/37/35 42/39/37/35 42/39/37/35 42/39/37/35 48/45/41/39 50/48/43/41 50/47/43/39
Indoor Unit
Dimensions (WxDxH) 33.5x10.62x8.19 33.5x10.62x8.19 33.5x10.62x8.19 33.5x10.62x8.19 42.5x12.37x9 42.5x12.37x9 52.75x14.83x10.81
Packing (WxDxH) 35.87x13.13x10.25 35.87x13.13x10.25 35.87x13.13x10.25 35.87x13.13x10.25 48x15.75x12.19 48x15.75x12.19 56.12x15.56x18.12
Net/Gross Weight 18.5/23.1 18.5/23.1 18.5/23.1 18.5/23.1 30.9/37.5 29.8/37.5 40.8
Outdoor Unit
Outdoor Air Flow (Hi) 470 488 470 488 588 647 647
Outdoor Side Noise Level 53 53 53 53 58 60 60
Dimensions (WxDxH) 28.13×21.25×9.5 28.13×21.25×9.5 28.13×21.25×9.5 28.13×21.25×9.5 31.88x23x11 33.88×25.5×12.2 35.43x13.38x29.5
Packing (WxDxH) 32.67x23.62x13.18 32.67x23.62x13.18 32.67x23.62x13.18 32.67x23.62x13.18 37x25.19x15.15 39.17×28.34×16.53 41.75x17.69x32.31
Net/Gross Weight 52.9/61.7 57.3/66.1 48.5/57.3 52.9/61.7 75/82.7 101.4/110.2 121.3
Refrigerant
Refrigerant Type/Quantity R32/21.2 R32/21.9 R32/20.5 R32/21.9 R32/45.9 R32/47.6 R32/72.4
Refrigerant Precharge 24.6 24.6 24.6 24.6 24.6 24.6 24.6
Design Pressure 620 620 620 620 620 620 620
Liquid Side / Gas Side 1/4'' / 3/8'' 1/4'' / 3/8'' 1/4'' / 3/8'' 1/4'' / 3/8'' 1/4'' / 1/2'' 3/8'' / 5/8'' 3/8'' / 5/8''
Refrigerant Piping
Max Refrigerant Pipe Length 65.6 65.6 65.6 65.6 98.4 98.4 98.4
Max. Difference in Level 49.2 49.2 49.2 49.2 49.2 49.2 49.2
Ambient Temperature
Indoor (Cooling/Heating) 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75
Outdoor (Cooling/Heating) 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75 5~118/-5~75
Energy Star Certified

What’s Included

What’s Included
Outdoor condenserOS-SR18-230VO
Indoor unitOS-18SRW-230VI
Remote controllerL1-12

Installation kit is not included in the selected option — pick 16ft, 25ft or 50ft above to add one.

Shipping & Returns

  • Free shipping on every order over $300.
  • Delivery estimate for your ZIP is shown in the buy box above.
  • Returns accepted per our policy — unopened units in original packaging.

Warranty

5-year manufacturer warranty

  • Limited manufacturer warranty on the compressor and sealed system components.
  • Your order number is the proof of purchase — keep it for any claim.

Multiple Control Methods

Olmo’s Sierra can be managed with a user-friendly remote control. This options offer precise temperature adjustments and optimal climate control for ultimate convenience.

App Promo

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Frequently Asked Questions

What size mini split do I need for my room?

For spaces up to 850 sq ft, the Olmo Sierra Series 18,000 BTU mini split is an excellent choice, providing efficient cooling and heating. Make sure to calculate your room size accurately to ensure optimal performance.

Can I install the Olmo mini split myself?

While DIY installation is possible for the Olmo Sierra Series, it requires knowledge of electrical and refrigerant systems. If you opt for a 16ft, 25ft, or 50ft installation kit, ensure you follow the manufacturer's guidelines closely for best results.

Does the Olmo mini split come pre-charged with refrigerant?

Yes, the Olmo Sierra Series mini split is pre-charged with R32 refrigerant for up to 25 ft of line set, making installation more straightforward. Just ensure your installation does not exceed this distance to maintain efficiency.

What voltage does the Olmo mini split require?

The Olmo Sierra Series operates on a 230V system, which is standard for many residential mini splits. Ensure your electrical system can accommodate this voltage before installation.

What warranty does the Olmo Sierra Series offer?

The Olmo Sierra Series comes with a 5-year parts and compressor warranty, providing peace of mind for your investment. This warranty covers the essential components to ensure your mini split operates efficiently over time.

What SEER rating do I need for energy efficiency?

With a SEER rating of 21.0, the Olmo Sierra Series mini split exceeds the minimum efficiency requirements, making it an excellent choice for energy savings. Look for systems with a SEER above 16 for optimal performance in various climates.