Trane M5THM2318A12NA Mini Split Indoor Wall Unit 18000 Btu/h 23 Seer Single Zone Ductless Heat Pump

Product Description

The Trane M5THM2318A12NA is a wall-mounted indoor unit designed for single-zone ductless mini-split heat pump systems. Rated at 18,000 BTU/h with an efficiency rating of up to 23 SEER, this unit handles both heating and cooling in residential and light-commercial applications. It operates on a single-phase power supply and uses R-454B refrigerant, aligning with current low-GWP refrigerant standards. Licensed HVAC technicians install this unit as part of a matched outdoor-unit system, connecting refrigerant lines, condensate drain, and low-voltage control wiring at the installation site.

This indoor wall unit is suited for single-zone applications where zone-level temperature control is required without ductwork. Typical installations include residential rooms, additions, sunrooms, offices, and server rooms where independent climate control is needed. The unit mounts high on the wall and delivers conditioned air directly into the space. It is matched with a compatible Trane outdoor condensing unit to complete the refrigerant circuit.

Key Features

• 18,000 BTU/h capacity for single-zone heating and cooling coverage
• Up to 23 SEER efficiency rating for reduced operating costs in variable-speed inverter systems
• R-454B refrigerant — low global warming potential, compliant with current refrigerant transition standards
• Single-phase operation compatible with standard residential electrical service
• Wall-mounted indoor configuration — no ductwork required
• Inverter-driven variable-capacity operation for precise temperature maintenance

Compatibility

Designed as an OEM-style indoor wall unit for Trane single-zone ductless mini-split systems. Must be paired with a matched Trane outdoor unit; consult Trane product documentation to confirm the correct outdoor unit pairing for this indoor model.

Installation Notes

Installation must be performed by an EPA Section 608 certified HVAC technician with experience in ductless mini-split systems. Before service or installation, de-energize the outdoor unit and confirm the circuit is locked out. Refrigerant line sets must be leak-tested and evacuated to the required vacuum level before charging. Condensate drainage must be routed per local mechanical code to prevent water damage.

Technical Specifications

• Capacity: 18,000 BTU/h
• Efficiency: Up to 23 SEER
• Refrigerant Type: R-454B
• Phases: 1
• System Type: Single-Zone Ductless Mini-Split
• Unit Configuration: Wall-Mounted Indoor

Standard Information

• Brand: Trane
• Manufacturer Part Number: M5THM2318A12NA