Quiet, efficient room-by-room comfort with straightforward installation and smart-control options.
Up to 2 zones. Inverter heat pump with up to 21 SEER2 and 12.5 EER2. For Multi-Sierra wall-mount indoor units.
Indoor units, line sets, communication cable, and accessories sold separately.
| Spec | Details |
|---|---|
| Model | OS-MSR18-230VO |
| System type | Multi-zone inverter heat pump |
| Cooling capacity (nom.) | 18,000 BTU/h |
| Heating capacity @ 47°F | 18,000 BTU/h |
| SEER2 / EER2 (up to) | 21 / 12.5 |
| HSPF2-5 / HSPF2-4 | 8.53 / 10.34 |
| Refrigerant | R410A |
| Refrigerant piping (liq/gas) | 1/4″ / 3/8″ |
| Refrigerant precharge | 25 (per spec) |
| Additional charge | 0.16 per ft for 1/4″ and 3/8″ liquid lines |
| Max pipe length (indiv./total) | 82 ft / 164 ft |
| Max height difference | 15 |
| Power | 208–230 V, 1-Phase, 60 Hz |
| Voltage range | 198–253 V |
| MCA / Max fuse | 21 A / 30 A |
| Outdoor noise | 55 dB(A) |
| Outdoor air flow | 1.85 (per spec) |
| Ambient temp (heat / cool) | −13~75.2°F / 14~114.8°F |
| Unit dimensions (W×H×D) | 33-7/8 × 26-3/8 × 12-1/4 in |
| Packing dimensions (W×D×H) | 39 × 17-3/4 × 28-3/4 in |
| Net / Gross weight | 116.8 / 125.6 lb |
| Compatible IDUs | OLMO Multi-Sierra wall-mount indoor units (up to 2 zones) |
Confirm port count, line sizes, and charge against the submittal and installation manual for your zone mix.