Mitsubishi SEZ-AD18NL & SUZ-AA18NL 18,000 BTU 17 SEER2 Horizontal Ducted Standard System - R454B

Mitsubishi SEZ‑AD18NL & SUZ‑AA18NL: 18,000 BTU Ducted Concealed Heat‑Pump System

The Mitsubishi SEZ‑AD18NL low-static horizontal-ducted indoor unit combined with the SUZ‑AA18NL outdoor condenser delivers a high-efficiency 18,000 BTU single-zone heat pump system, ideal for medium to large rooms, open-concept living areas, or multi-purpose office spaces. Designed for spaces requiring quiet, hidden comfort, this system features Mitsubishi’s INVERTER-driven compressor technology and eco-friendly R‑454B refrigerant for excellent temperature control and energy savings. The Blue Fin anti-corrosion coating on the outdoor coil protects the unit in humid, coastal, or polluted environments.

With a compact 7-7/8" height, the SEZ‑AD18NL is designed to fit into narrow ceiling cavities, soffits, or closets. It comes standard with a built-in 21” lift condensate pump for flexible drainage options in tight installations. Operating as quietly as 30 dB(A), this system minimizes noise without compromising performance. It’s ENERGY STAR® certified, offering reliable heating and cooling for spaces up to approximately 750 sq ft.

Control options include wired and wireless remotes, third-party thermostat compatibility, and full mobile access through Mitsubishi’s kumo cloud® app, giving users flexibility and convenience in system management.

General Information

System Type: Concealed ducted indoor unit + single-zone heat-pump condenser
Models: Indoor – SEZ‑AD18NL | Outdoor – SUZ‑AA18NL
Capacities: 18,000 BTU Cooling | up to 21,000 BTU Heating
Room Size: Ideal for ~750 sq ft
Operating Modes: Heating & Cooling
ENERGY STAR®: Yes
Refrigerant / Factory Charge: R‑454B, approx. 3.3 lb

Key Features

• INVERTER-Driven Compressor for precise load modulation and efficiency

• Slim 7-7/8" Profile for tight ceiling and soffit installations

• Built-In 21" Drain Pump simplifies condensate removal

• Quiet Operation with indoor sound levels starting at 30 dB(A)

• Blue Fin Anti-Corrosion Coating for extended outdoor unit life

• Advanced Controls including kumo cloud®, remote, and thermostat interface

Specifications (Rated Conditions)

Cooling Capacity: 18,000 BTU
Heating Capacity: Up to 21,000 BTU
Electrical: 208/230 V · 1-Ph · 60 Hz
Indoor Sound: 30–38 dB(A) (Lo–Hi)
Piping: Liquid 1/4 in. | Gas 1/2 in. | Max length 100 ft | Max height 50 ft
Outdoor Dimensions / Weight: ~33" W × 13" D × 34" H · ~115 lb

Included Components

• Indoor Unit: SEZ‑AD18NL horizontal ducted air handler

• Outdoor Unit: SUZ‑AA18NL heat-pump condenser

Ideal For

Homeowners and business owners who want a sleek, concealed ducted solution for heating and cooling larger single zones like living rooms, studio apartments, or office suites. The system delivers quiet, energy-efficient performance, modern controls, and Mitsubishi’s trusted reliability.