Mitsubishi SEZ-AD18NL & SUZ-AA18NL 18,000 BTU 17 SEER2 Horizontal Ducted Standard System - R454B - SEZAD18NL/SUZAA18NL
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.
Features
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INVERTER-Driven Compressor for precise load modulation and efficiency
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Slim 7-7/8" Profile for tight ceiling and soffit installations
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Built-In 21" Drain Pump simplifies condensate removal
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Quiet Operation with indoor sound levels starting at 30 dB(A)
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Blue Fin Anti-Corrosion Coating for extended outdoor unit life
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Advanced Controls including kumo cloud®, remote, and thermostat interface
What Our Experts Think
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Excellent choice for medium–large rooms or open-concept living areas up to ~900 sq ft.
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Low-static horizontal-ducted design provides discreet, quiet comfort with short duct runs.
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18,000 BTU heating/cooling with a solid 17 SEER2 efficiency rating.
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INVERTER-driven compressor ensures precise temperature control and reduced energy use.
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Uses next-generation, low-GWP R-454B refrigerant for a greener footprint.
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Outdoor unit features Blue Fin anti-corrosion coating—ideal for coastal or humid regions.
Q&A
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Q: What type of installation is this system best for?
A: Low-static horizontal ducting—perfect for ceilings, attics, and tight cavities requiring short supply runs.
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Q: How large of a space can it handle?
A: Generally suited for areas up to ~900 sq ft, depending on insulation and layout.
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Q: Is it a heat pump?
A: Yes—provides both heating and cooling in a single-zone configuration.
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Q: How quiet is the system?
A: Very quiet thanks to Mitsubishi’s INVERTER technology and concealed duct design.
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Q: Does the outdoor unit have durability features?
A: Yes—Blue Fin coating protects against corrosion in harsh or coastal climates.
Maintenance Tips
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Clean or replace return-air filters monthly to maintain airflow and SEER2 efficiency.
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Ensure ducts are properly sealed and insulated to minimize energy loss.
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Keep the outdoor unit clear of leaves, snow, and obstructions.
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Schedule professional annual maintenance to check refrigerant levels and system health.
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Inspect condensate drains seasonally to prevent clogs and water issues.
