OLMO Sierra 42,000 BTU Outdoor Condenser, 230V, R454B - Mini Split Air Conditioner Heat Pump
OLMO5-Yr Warranty
Product specifications
| Brand | |
|---|---|
| Voltage | |
| SEER | |
| Type | |
| Freon | |
| Compressor |
⛔ Wait! This is an Individual Component To build a working system, this unit must match your other equipment in two ways:
- Same Brand Only: Only pair with other same Brand and Series.
- Same Refrigerant: Both units must use the exact same gas type (R454B, R32, or R410A).
Mixing different brands or refrigerant types will cause the system to fail and void your warranty.
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
Pickup currently unavailable at Medley Warehouse
Questions about this system?
Answers in seconds — tap a question below
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Sized for about 1800–2400 sq ft. Rule of thumb: ~20 BTU per sq ft, and 12,000 BTU = 1 ton (this unit is 42,000 BTU (3.5-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.
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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 42,000 BTU (3.5-ton). BTU tells you the capacity; SEER2 tells you the efficiency.
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It uses R454B — the newest low-GWP eco refrigerant, so it's future-proof and efficient. 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.
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Rated SEER2 22.0 — 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.
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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.
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Yes — a big upgrade. It's far more efficient (inverter, SEER2 22.0) 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.
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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.
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Ships as a complete set: OS-RMS42-230VO. Everything arrives together — check the photos and specs for the full kit.
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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.
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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.
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 42000 BTU of heating & cooling — modern looks with whisper-quiet operation.
Inverter Efficiency — SEER2 22
A variable-speed inverter compressor ramps to match the load instead of cycling on/off, holding SEER2 22 on 230V — steady comfort with noticeably lower energy bills.
Right-Sized Coverage
Engineered to heat & cool up to 1800–2400 sq ft — matched capacity so you never over- or under-size the space.
Sierra Wall Mount
OLMO's Multi-Zone Sierra Series is a versatile HVAC solution that provides efficient heating and cooling for multiple rooms, featuring advanced inverter technology for precise temperature control and significant energy savings. Using eco-friendly R410A refrigerant, the system delivers reliable performance with minimal environmental impact. Ideal for both residential and commercial applications, the Sierra Series combines quiet operation, flexible installation, and user-friendly controls, making it a perfect choice for maintaining year-round comfort across multiple zones with one efficient system.
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
Main Features
OLMO's Multi-Zone Sierra Series delivers efficient multi-room comfort with advanced inverter technology for precise temperature control. Its eco-friendly R454B 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.
Technical Specifications
Outdoor Unit Specs
| Model | OS-RMS42-230VO |
|---|---|
| Net/Gross Weight | 172/194 lb |
| Power Supply | 208-230V, 1Ph, 60Hz |
| Maximum Fuse Size | 60 A |
| Min. Circuit Ampacity | 36 A |
System Specs
| Cooling Capacity | 42,000 BTU |
|---|---|
| SEER2 | 22 |
| Voltage | 230V |
| Refrigerant Type | R454B |
| Compressor | Inverter |
Series Comparison Table
Technical specifications for every model in the series — this product is one of them.
| Indoor Models | OS-RM09SW-230VI | OS-RM12SW-230VI | OS-RM18SW-230VI | OS-RM24SW-230VI |
|---|---|---|---|---|
| Power Supply (V-Ph-Hz) | 208/230V-1Ph-60 | 208/230V-1Ph-60 | 208/230V-1Ph-60 | 208/230V-1Ph-60 |
| Cooling Capacity (Btu/h) | 9000 | 12000 | 18000 | 23400 |
| Heating Rated Capacity (Btu/h) | 9500 | 13000 | 19000 | 26000 |
| Output Power (W) | 25 | 25 | 35 | 35 |
| Rated Current (A) | 0.11 | 0.11 | 0.17 | 0.17 |
| Indoor Air Flow (CFM) | 341 | 365 | 647 | 706 |
| Indoor Noise Level (Hi/Mi/Lo) (dB(A)) | 39/35/30 | 39/35/30 | 45/41/37 | 47/45/42 |
| Net Dimensions (WxHxD) (in) | 32.02x10.75x8.13 | 37.38x10.75x8.13 | 48x12.63x9.25 | 48x12.63x9.25 |
| Packing (WxHxD) (in) | 39.38x13.19x6.38 | 39.38x13.19x6.38 | 51.75x15.44x12.50 | 51.75x15.44x12.50 |
| Net/Gross Weight (lbs) | 19.84 / 24.25 | 19.84 / 24.25 | 31.97 / 37.48 | 31.97 / 37.48 |
| Refrigerant Piping (Liquid Side / Gas Side) (in) | 1/4" / 3/8" | 1/4" / 3/8" | 1/4" / 1/2" | 3/8" / 5/8" |
| Outdoor Models | OS-RMS18-230VO | OS-RMS24-230VO | OS-RMS36-230VO | OS-RMS42-230VO |
|---|---|---|---|---|
| Power Supply (V-Ph-Hz) | 208/230V-1Ph-60 | 208/230V-1Ph-60 | 208/230V-1Ph-60 | 208/230V-1Ph-60 |
| Cooling Capacity (Btu/h) | 18000 | 27000 | 36000 | 42000 |
| EER2 | 13.33 | 12.85 | 12.85 | 12.0 |
| SEER2 | 22.0 | 23.0 | 22.0 | 22.0 |
| Heating Rated Capacity (Btu/h) | 18000 | 27000 | 36000 | 36000 |
| HSPF2 | 10.0 | 10.0 | 10.0 | 9.5 |
| COP2 (W/W) | 3.82 | 3.60 | 3.91 | 3.60 |
| Max Fuse (A) | 30 | 40 | 50 | 60 |
| Outdoor Air Flow (Hi) (CFM) | 1850 | 3357 | 3357 | 3357 |
| Outdoor Side Noise Level (dB(A)) | 55 | 62 | 64 | 64 |
| Dimensions (WxHxD) (in) | 33.88x26.38x12.25 | 38.38x32.88x14.12 | 38.38x32.88x14.12 | 38.38x32.88x14.12 |
| Outdoor Unit Packing (WxHxD) (in) | 39x28.75x17.75 | 43.75x37.75x18.12 | 43.75x37.75x18.12 | 43.75x37.75x18.12 |
| Net/Gross Weight (lbs) | 101.4/112.4 | 160.6/183.2 | 169.8/191.8 | 172/194 |
| Refrigerant Type/Quantity (oz) | R454B/51.15 | R454B/76.2 | R454B/105.8 | R454B/105.8 |
| Refrigerant Piping (Liquid Side / Gas Side) (in) | 1/4" / 3/8" | 1/4" / 3/8" | 1/4" / 3/8" | 1/4" / 3/8" |
| Max Refrigerant Pipe Length Each/Total (ft) | 82/164 | 82/230 | 82/230 | 82/262 |
| Ambient Outdoor (Cooling) (°F) | 5~125 | 5~125 | 5~125 | 5~125 |
| Ambient Outdoor (Heating) (°F) | -13~75 | -13~75 | -13~75 | 4~75 |
What’s Included
| Outdoor condenser | OS-RMS42-230VO |
|---|
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 Multi-Zone Sierra Series can be managed with a user-friendly remote control and the. This options offer precise temperature adjustments and optimal climate control for ultimate convenience.
Frequently Asked Questions
What size mini split do I need for my home?
To determine the appropriate size for your space, consider that the Olmo Sierra 42,000 BTU model can effectively cover varying square footage, depending on insulation and layout. For larger areas, this high-capacity unit is ideal, especially in open-concept designs.
Can I install the Olmo mini split myself?
While some homeowners attempt DIY installation, it's important to note that the Olmo Sierra requires professional installation for optimal performance and compliance with local codes. The unit offers optional installation kits up to 50 feet, which can be beneficial if you decide to hire professional help.
Does the Olmo mini split come pre-charged with refrigerant?
Yes, the Olmo Sierra mini split comes pre-charged with R454B refrigerant for up to 25 ft of line set, making installation simpler. However, additional refrigerant may be required if your installation exceeds this length.
What voltage does the Olmo mini split require?
The Olmo Sierra operates on a standard voltage of 230V, making it suitable for most residential electrical systems. Ensure your home's electrical setup can accommodate this voltage for safe operation.
What warranty does the Olmo Sierra offer?
The Olmo Sierra comes with a comprehensive 5-year parts and compressor warranty, providing peace of mind with your investment. This warranty ensures that you have coverage for potential issues during the initial years of use.
What is the SEER rating of the Olmo mini split, and why is it important?
The Olmo Sierra boasts an impressive SEER rating of 22.0, indicating high energy efficiency. A higher SEER rating means lower energy costs and a smaller environmental footprint, making this unit an excellent choice for both cooling and heating needs.
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