HOT ! MRCOOL DIY® 5th Gen 18,000 BTU Multi-Zone Mini Split Condenser 230V

MRCOOL DIY® 18,000 BTU Mini Split Condenser for Multi-Zone Comfort & Easy DIY Installation

The MRCOOL DIY® 5th Gen 18,000 BTU Multi-Zone Mini Split Condenser is built to deliver efficient heating and cooling across multiple rooms from a single outdoor unit. Designed for up to three indoor air handlers, this mini split condenser allows you to control different zones independently, ideal for small homes, apartments, offices, workshops, or additions.

Engineered for DIY installation, this condenser pairs with pre-charged DIY® Quick Connect® line sets, eliminating the need for vacuum pumps, refrigerant handling, or HVAC certification. With ENERGY STAR® efficiency, inverter-driven performance, and smart control compatibility, it provides reliable comfort with lower energy usage.

Important Notes and Recommended Coverage Area

• This listing includes the outdoor mini split condenser only. Indoor air handlers and line sets are sold separately.

• Designed to serve 750–1,100 sq. ft., depending on insulation quality, ceiling height, and climate zone.

Whole-Home Comfort with a Flexible Ducted Mini Split Solution

Designed to work seamlessly with MRCOOL DIY® condensers, this hybrid ducted air handler delivers efficient heating and cooling throughout your main living space while allowing additional zones to be served separately. Pair it with a wall-mounted air handler or an OuttaSight® Ceiling Cassette to independently condition a garage, office, or bonus room, giving you more control, better efficiency, and a cleaner installation without sacrificing comfort anywhere in your home.

Key Features & Benefits

Multi-Zone Heating & Cooling from One Condenser

• Supports up to three indoor air handlers with a maximum combined capacity of 24,000 BTU


• Independently control temperatures in different rooms for customized comfort


• Flexible sizing options using 6K, 9K, and 12K BTU air handlers

DIY Installation — No HVAC License Required

• Compatible with DIY® Quick Connect® pre-charged line sets


• No vacuuming, refrigerant handling, or specialized tools required


• Designed for homeowners who want professional-grade performance without professional installation

Energy-Efficient Performance with R-454B Refrigerant

• Uses R-454B, a lower-GWP refrigerant that replaces R-410A


• Inverter-driven compressor adjusts output based on demand


• ENERGY STAR® efficiency with SEER2 up to 20.5 for reduced operating costs

Smart Control Compatibility

• Control each zone using the SmartHVAC App (iOS & Android)


• Voice control compatible with Amazon Alexa and Google Assistant


• Manage comfort remotely without additional accessories

Built for Long-Term Outdoor Durability

• Gold Fin® condenser coating resists corrosion and salt air


• DIYPRO® armored cable eliminates the need for an electrical conduit


• Designed for year-round outdoor operation in demanding environments

Certified & Backed by Strong Warranty Coverage

• Intertek Listed (5031495) for safety and performance


• 7-Year Compressor Warranty


• 5-Year Parts Warranty


• Limited Lifetime Replacement Warranty with MRCOOL® Care Program registration

Compatible Air Handler Combinations

This mini split condenser supports up to three zones with flexible configurations, including:

• 6K + 6K + 12K (24,000 BTU)


• 6K + 9K + 9K (24,000 BTU)


• 6K + 6K + 9K (21,000 BTU)

• 9K + 9K (18,000 BTU – one port unused)


• 6K + 12K (18,000 BTU – one port unused)

📌 Always verify total connected BTU capacity before purchasing.

Specifications

• 
  Model Number: DIY-MULTI3-18HP230D-O


• 
  Cooling Capacity: 18,000 BTU/h


• 
  Heating Capacity: 19,000 BTU/h


• 
  Recommended Coverage Area: 750–1,100 sq. ft.


• 
  SEER2: 20.5


• 
  EER2: 11.5


• 
  HSPF2-4: 10.3


• 
  HSPF2-5: 8.5


• 
  Power Supply: 208–230V, 60Hz, single-phase


• 
  Minimum Circuit Ampacity: 18 A


• 
  Maximum Fuse Size: 25 A


• 
  Refrigerant Type: R-454B


• 
  Refrigerant Charge: 67.37 oz


• 
  Line Set Sizes: 3/8\" liquid x 5/8\" gas


• 
  Net Dimensions (W x D x H): 37.24\" x 16.14\" x 31.89\"


• 
  Net Weight: 122.80 lbs


• 
  Recommended Wire Size: 12 AWG (ideal for 18A load)


• 
  Smaller Wire Size (Risk): 14 AWG – may overheat or fail to meet code under full load


• 
  Larger Wire Size (Benefit): 10 AWG – reduced voltage drop and added safety margin

Frequently Asked Questions