Mitsubishi MSY-GX12NL & MUY-GX12NL 12,000 BTU 25.6 SEER2 Wall Mounted Cooling Only System - R454B

Mitsubishi MSY-GX12NL & MUY-GX12NL: 12,000 BTU Wall-Mounted Cooling-Only System

The Mitsubishi MSY-GX12NL indoor unit, paired with the MUY-GX12NL outdoor unit, delivers high-efficiency 12,000 BTU cooling in a single-zone ductless mini-split. Sized for rooms up to 500 sq ft, it combines INVERTER-driven precision, whisper-quiet operation, and ENERGY STAR® performance in a slim, low-profile design.

Dual Barrier and Blue Fin coatings protect internal surfaces from dust, oil, and corrosion, while built-in Wi-Fi (Comfort app ready) and a back-lit remote offer flexible control. The system maintains reliable cooling down to –1 °F outdoor temperature, making it ideal for year-round comfort in hot or shoulder seasons.

General Information
System Type: Wall-mounted ductless air handler + single-zone cooling-only condenser
Models: Indoor – MSY-GX12NL | Outdoor – MUY-GX12NL
Capacities: 12,000 BTU Cooling (14,000 BTU max)
Room Size: Ideal for 500 sq ft
Operating Modes: Cooling
ENERGY STAR®: Yes
Refrigerant / Factory Charge: R-454B, 2.0 lb

Key Features

• INVERTER Technology: Variable-speed compressor for precise, energy-saving output

• Low-Ambient Cooling: Operates to –1 °F outdoor temp for server or comfort loads

• Space-Saving Design: Slim wall unit blends easily into any décor

• Quiet Operation: Indoor sound as low as 19 dB(A); outdoor ≈ 49 dB(A)

• Washable Nano-Platinum Filter: Long-life, easy-clean air filtration

• Built-In Wi-Fi: Full Comfort-app control, plus wired/wireless remote options

Specifications (Rated Conditions)
Cooling Capacity: 12,000 BTU | EER2: 13.35 | SEER2: 25.6
Electrical: 208/230 V, 1-Ph, 60 Hz | MCA: 12 A | MOCP: 21 A
Airflow (Dry): 151–448 CFM
Sound Pressure: Indoor 19–45 dB(A) | Outdoor 49 dB(A)
Piping: Liquid ¼ in. | Gas ⅜ in. | Max line length 65 ft | Max height 40 ft
Outdoor Dimensions / Weight: 31-½ × 11-¼ × 21-⅝ in. | 77 lb
Drain Connection: ⅝ in. O.D.

Included Components

• Indoor Unit: MSY-GX12NL wall-mounted air handler

• Outdoor Unit: MUY-GX12NL cooling-only condenser

• Back-Lit Hand-Held Remote Controller

Ideal For
Homeowners or contractors needing quiet, energy-efficient cooling for medium-sized rooms. The MSY-GX12NL & MUY-GX12NL provide dependable performance, smart control, and low maintenance in a sleek, space-saving package.