Mitsubishi PAA-BA42NL & PUZ-AK42NL 42,000 BTU 17.1 SEER2 Cased Coil Heat Pump System - R454B

Mitsubishi PAA-BA42NL & PUZ-AK42NL: 42,000 BTU Heat Pump Split System

The Mitsubishi PAA-BA42NL indoor cased coil paired with the PUZ-AK42NL outdoor heat pump delivers powerful year-round heating and cooling for residential and light commercial applications. Designed for compatibility with gas furnace systems and hybrid HVAC installations, this 42,000 BTU split system combines Mitsubishi’s advanced inverter-driven technology, intelligent comfort management, and durable construction to provide dependable performance in a wide range of climates.

The PAA-BA42NL indoor unit is engineered for compatibility with most ANSI-certified gas furnaces and supports Mitsubishi intelli-HEAT® technology, allowing intelligent switchover between heat pump and furnace operation when installed in hybrid applications. This intelligent functionality can optimize comfort, maximize energy efficiency, and reduce overall energy costs by automatically selecting the most effective heating source based on outdoor conditions. The indoor unit features a high-quality drain pan with excellent heat tolerance and low moisture absorption for long-term reliability. Flexible multi-position installation supports horizontal left, horizontal right, upflow, and downflow configurations, making the system adaptable to a variety of residential and commercial HVAC applications.

The PUZ-AK42NL outdoor condenser utilizes Mitsubishi’s INVERTER-driven twin rotary compressor technology to precisely match heating and cooling demand. Unlike conventional systems that cycle on and off at full capacity, inverter technology continuously adjusts compressor speed to maintain consistent indoor temperatures, improve efficiency, and reduce energy consumption. The system delivers up to 43,000 BTU of cooling capacity and up to 50,000 BTU of heating capacity at 47°F, providing powerful comfort throughout the year.

Built for durability in demanding environments, the outdoor unit features Blue Fin anti-corrosion coating and Seacoast Protection to help protect the heat exchanger from salt, sulfur, and airborne contaminants. These advanced protective features help extend system life and maintain performance in coastal and harsh outdoor environments. The system provides dependable heating operation down to -4°F outdoor temperatures and supports cooling operation from 23°F to 115°F, with cooling operation down to 0°F when equipped with optional wind baffles.

Despite its powerful performance, the system maintains quiet operation with outdoor sound levels as low as 52 dB(A) in cooling mode and 53 dB(A) in heating mode. Advanced control options support Mitsubishi Comfort app connectivity, kumo station®, BACnet® and Modbus® interfaces, wired and wireless controllers, remote temperature sensors, and third-party thermostat integration for flexible comfort management and building automation compatibility.

General Information

System Type: Cased coil indoor unit + single-zone heat pump outdoor unit

Models: Indoor – PAA-BA42NL | Outdoor – PUZ-AK42NL

Capacities: 42,000 BTU Rated Cooling (Max 43,000 | Min 15,400)

Heating Capacity: 50,000 BTU at 47°F | 32,600 BTU at 17°F | 26,600 BTU at 5°F

Room Size: Ideal for residential and light commercial spaces up to ~2,000–2,500 sq ft

Operating Modes: Heating & Cooling

ENERGY STAR®: No

Refrigerant / Factory Charge: R-454B, 9 lb 14 oz (pre-charged for 100 ft line length)

Key Features

INVERTER-Driven Twin Rotary Compressor: Precise heating and cooling output for enhanced efficiency

intelli-HEAT® Compatibility: Intelligent hybrid furnace integration capability

Heat Pump Operation: Year-round heating and cooling from a single system

High Airflow Performance: Up to 1,660 CFM indoor airflow

Blue Fin Coating: Corrosion-resistant outdoor heat exchanger protection

Seacoast Protection: Enhanced durability in coastal and harsh environments

Reverse Cycle Defrost: Reliable cold-weather heat pump performance

Quiet Operation: Outdoor sound levels as low as 52 dB(A) cooling and 53 dB(A) heating

Flexible Installation: Multi-position indoor installation configurations

Smart Controls: Comfort app compatibility, wired/wireless remotes, thermostat and building automation interfaces

Specifications (Rated Conditions)

Cooling Capacity: 42,000 BTU (Max 43,000 | Min 15,400) | SEER2: 17.1 | EER2: 10.3

Heating Capacity: 50,000 BTU at 47°F | 32,600 BTU at 17°F | HSPF2: 9.3

COP: 3.1 at 47°F | 2.60 at 17°F | 2.30 at 5°F

Electrical: 208/230 V, 1-Ph, 60 Hz | Outdoor MCA: 34 A | MOCP: 56 A

Indoor Airflow: 936–1,660 CFM

Outdoor Sound: 52 dB(A) Cooling | 53 dB(A) Heating

Piping: Liquid 3/8 in | Gas 5/8 in | Max line length: 100 ft | Max height: 100 ft

Outdoor Operating Range: Cooling 23°F to 115°F | Heating down to -4°F

Heating Thermal Lock-Out / Restart: -13°F / -4°F

Outdoor Dimensions / Weight: 41-11/32 × 14 × 52-43/64 in | 224 lb

Indoor Dimensions / Weight: 17-1/2 × 21-3/8 × 32 in | 72.8 lb (cased coil)

Drain Connection: 3/4 in O.D.

Included Components

Indoor Unit: PAA-BA42NL cased coil indoor unit

Outdoor Unit: PUZ-AK42NL inverter-driven heat pump condenser

Ideal For

Homes and light commercial spaces seeking efficient year-round heating and cooling with advanced inverter technology and hybrid furnace compatibility. The Mitsubishi PAA-BA42NL & PUZ-AK42NL system delivers powerful heat pump performance, precise temperature control, quiet operation, corrosion-resistant durability, and dependable comfort for larger residential and commercial applications.