Description
Overview
Mitsubishi Electric pairs the MFZ-KX15NL floor-mounted indoor unit with the SUZ-AA15NL outdoor unit to deliver ductless cooling and heating in a matched system. Rated cooling capacity is 15,000 Btu/h, and rated heating capacity at 47°F is 18,000 Btu/h for year-round conditioning. The indoor unit mounts on the floor or up to 5 inches above the floor and can also be recessed into a wall for low-profile placement. The refrigerant circuit uses R454B, and the electrical supply is 208/230V, 1-phase, 60Hz. Line connections use 1/4 in liquid and 1/2 in gas piping with flared joints, supporting up to 65 ft total piping length and up to 40 ft height difference. The outdoor unit ships pre-charged with 2 lb 4 oz of refrigerant for up to 25 ft of piping, with additional charge of 0.22 oz/ft beyond that length.
Performance
Efficiency ratings include 20.1 SEER2 and 10.5 HSPF2, with 13 EER2 and ENERGY STAR certification listed for this system. Capacity control comes from an inverter-driven compressor that delivers the precise output needed to hold the temperature set point. The outdoor unit uses a Twin rotary compressor and Pulse Amplitude Modulation technology to adjust power delivery for compressor performance and capacity control. Cooling performance is rated at 15,000 Btu/h with rated power input of 1,150 W, and moisture removal is 3.2 pints/h under rated cooling conditions. Heating performance is rated at 18,000 Btu/h at 47°F with rated power input of 1,360 W, and defrost uses a Reverse cycle method. The outdoor heat exchanger uses high-performance grooved piping and includes Blue Fin coating on aluminum fins to help protect against corrosion in coastal or industrial air.
Smart Features
Control options include a hand-held remote controller provided with the indoor unit, plus compatibility with wired and wireless controllers and third-party interfaces. Wi‑Fi enabled operation supports use with the Comfort app for adjusting temperature, fan speeds, modes, and schedules from a mobile device. The system supports multiple fan speed selections including Low, Medium, High, Powerful, and Auto to match load and sound preferences. Econo Cool temporarily adjusts airflow based on heat exchanger temperature while slightly increasing the set temperature to reduce energy use during cooling. Powerful Mode temporarily changes set point and fan speed for fast pull-down or warm-up when you need quick response. Control voltage between indoor and outdoor includes 12–24 V DC on the S2–S3 circuit, supporting compatible control and interface options.
Comfort & Noise
Indoor airflow spans 198–431 CFM in cooling (dry) and 212–470 CFM in heating (dry) across multiple fan steps. Indoor sound pressure levels are listed from 28–47 dB(A) in cooling, supporting low-sound operation for noise-sensitive spaces. Outdoor sound pressure is 49 dB(A) in cooling and 51 dB(A) in heating for predictable exterior sound planning. A Multi-flow Vane helps deliver faster heating, and up-and-down swing mode moves air vertically through the space using the horizontal vanes. Hot-Start Technology keeps the fan from activating until the heat exchanger is warm, reducing cold-air sensation during heating start-up. Nano Platinum filtration is included, and the front-panel filter access supports routine cleaning without removing the unit.
Use Case Fit
The floor-mounted format is built for areas that are smaller or do not have usable wall space, including rooms where low-wall placement is preferred. Cooling operation supports outdoor intake temperatures from 14°F to 115°F outdoor dry-bulb, and the system is intended for comfort cooling applications. Heating operation supports outdoor temperatures down to -4°F outdoor dry-bulb, making it suitable for shoulder-season and winter operation within the listed range. Piping flexibility includes up to 65 ft total length, up to 40 ft elevation difference, and up to 10 bends for routing around building constraints. The indoor unit size is 29-1/2 x 8-7/16 x 23-5/8 inches (W x D x H), while the outdoor unit is 31-1/2 x 11-1/4 x 21-5/8 inches for footprint planning. Drain connection uses a 5/8 in outside diameter drain outlet to support condensate routing for typical installations.
Value & Reliability
Blue Fin coating helps protect the outdoor heat exchanger against corrosion caused by salt, sulfur, and other airborne contaminants. Optional base pan heating support is provided to help manage winter conditions and defrost drainage for the outdoor unit. Outdoor unit directed power supplies the indoor unit, and the system restarts automatically when power returns after an outage. Front-panel filter access and washable filtration support routine maintenance tasks without disassembling the indoor cabinet. The outdoor unit is rated for a 20 A recommended fuse/breaker size and uses 14 AWG recommended indoor-to-outdoor wiring. Refrigerant piping uses flared 1/4 in liquid and 1/2 in gas connections with a maximum pre-charged length of 25 ft before additional refrigerant is required.
Summary Wrap-Up
This Mitsubishi Electric floor-mounted ductless system delivers 15,000 Btu/h cooling with inverter control and a compact indoor footprint for tight spaces. Buyers get multiple control paths, including the included handheld remote and app-capable control for scheduling and day-to-day adjustments. Airflow and vane functions support whole-room circulation, while published sound ratings help match the system to noise-sensitive rooms. Outdoor operating ranges and routing limits are clearly defined, including up to 65 ft piping length and 40 ft elevation change for placement flexibility. For contractors and wholesale purchasers, listed electrical requirements and line sizes simplify takeoffs and job planning. For direct-to-consumer replacements, this matched indoor and outdoor pairing provides a straightforward path to ductless comfort using R454B refrigerant.
Key Features
- 15,000 BTU cooling capacity: Rated cooling output with 3,300–15,000 Btu/h capacity range to match load.
- 18,000 BTU rated heating at 47°F: Rated heating output with 4,900–20,400 Btu/h capacity range at 47°F conditions.
- 20.1 SEER2 and 10.5 HSPF2 ratings: Listed efficiency values with ENERGY STAR certification for buyers comparing performance.
- Inverter-driven compressor control: Inverter-driven compressor and Pulse Amplitude Modulation technology provide precise capacity control.
- Floor-mounted or low-wall placement: Mounts on the floor or up to 5 inches above the floor and can be recessed into a wall.
- Blue Fin coated heat exchanger: Blue Fin coating is applied to the aluminum fins of the outdoor heat exchanger to protect against corrosion.
- Single-space system pairing: One outdoor unit connects to one indoor unit to control comfort in a single space.
