MRCOOL DIY 5th Gen 27K 2-Zone Mini Split System 9K + 12K Multi-Zone R-454B Pre-Charged 16 ft Line Sets

MRCOOL DIY 5th Gen 27K 2-Zone Mini Split System 9K + 12K Multi-Zone R-454B Pre-Charged 16 ft Line Sets

The MRCOOL DIY 5th Gen 27K 2-Zone Mini Split System (9K + 12K) offers customizable, whole-home comfort for two separate rooms with a system designed for true DIY installation. It bundles a 27,000 BTU multi-zone outdoor condenser with one 9,000 BTU indoor air handler and one 12,000 BTU indoor air handler, perfect for cooling and heating zones like bedrooms, offices, and living spaces. This bundle includes two 16 ft pre-charged DIY® QuickConnect® line sets that come factory sealed with R-454B refrigerant, so there’s no vacuum pump, refrigerant tools, or professional installation required — just connect, tighten, and power up.

This 2-zone system delivers efficient year-round comfort with up to 23 SEER2 cooling and 9.5 HSPF2-4 heating performance, helping you save on energy bills compared to traditional HVAC systems or multiple window units. Each indoor unit provides independent temperature control so occupants in different rooms can enjoy personalized comfort settings. The 9K unit is ideal for smaller areas like home offices or bedrooms, while the 12K unit offers capacity for larger spaces such as living rooms or master suites, making the system versatile for a variety of home environments.

Included wireless remotes make on-the-spot temperature adjustments simple, and you can also take advantage of SmartHVAC app control and compatibility with Amazon Alexa and Google Assistant for voice-enabled convenience. Quiet operation ensures minimal disruption whether you’re sleeping, working, or entertaining.

This MRCOOL mini split system is built around robust inverter technology and eco-friendly refrigerant that supports up to four indoor units, giving you flexibility to expand your comfort solution in the future if needed. Its industry-tested QuickConnect® design and energy-efficient performance make it a reliable choice for homeowners seeking comfort without complex installation.

Features

• DIY® QuickConnect® 16 ft pre-charged line sets — no vacuum pump or refrigerant tools required

• Independent dual-zone control — separate temperature settings for each indoor unit

• Eco-friendly R-454B refrigerant

• Up to 23 SEER2 cooling efficiency and 9.5 HSPF2-4 heating performance

• SmartHVAC app control; Amazon Alexa & Google Assistant compatible

• Multiple operating modes: Cool, Heat, Auto, Dry (dehumidify), Fan, Sleep

• Quiet, efficient inverter operation

• Expandable condenser supports up to 4 indoor units

Specifications

System Overview (Condenser)

Outdoor Condenser – DIY-MULTI4-27HP230D-O

• BTU Capacity: 26,000 cooling / 26,000 heating (~27K class)
• Zones Supported: Up to 4 indoor units (this bundle uses 2)
• Efficiency: 23 SEER2, 12 EER2, 9.5 HSPF2-4, 7 HSPF2-5
• Tonnage: 2.25 tons
• Refrigerant: R-454B (pre-charged, eco-forward)
• Voltage: 208/230V, 1-Phase, 60 Hz
• Inverter: DC inverter rotary compressor
• Sound Level: 61 dBA (outdoor)
• Line Sizes: 1/4” liquid, 3/8” suction
• Max Line Length Total: 221.4 ft
• Max Fuse Breaker: 25A
• Minimum Circuit Ampacity: 23A
• NET Dimensions (W×H×D): 37.24” × 31.89” × 16.14”
• Net Weight: 140.21 lbs

 Indoor Units (2-Zone Bundle)

9K Wall Mount Air Handler – DIY-09-HP-WMAH-230D25-O

• Room Size: Up to 400 sq ft
• Mount Type: Wall mount
• Voltage: 208/230V, 1-Phase
• Control: Remote, SmartHVAC app, Alexa, Google
• Modes: Cool, Heat, Auto, Dry (dehumidify), Fan, Sleep
• Filter: Reusable
• NET Dimensions (W×H×D): 31.57” × 11.69” × 7.44”
• Net Weight: 24.47 lbs

12k Wall Mount Air Handler – DIY-12-HP-WMAH-230D25-O

• Room Size: Up to 550 sq ft
• Voltage: 208/230V, 1-Phase
• Max Fuse Breaker (indoor circuit): 15A (shared system circuit)
• Min Circuit Ampacity (unit): 
• Sound: 19–54.5 dBA (low–high)
• Line Sizes: 1/4” liquid, 1/2” suction
• NET Dimensions (W×H×D): 31.57” × 11.63” × 7.44”
• Net Weight: 24.47 lbs

 Included Line Sets

2 × DIY16-1438-O – 16 ft Pre-Charged Line Sets

• Length: 16 ft each
• Size: 1/4” × 3/8” 
• Refrigerant: R-454B (2.12 oz per set, pre-charged)
• Type: DIY® QuickConnect® – no vacuuming, no charging
• Use: Compatible with DIY 6K, 9K, 12K indoor units

Each line set includes factory-sealed QuickConnect® fittings for fast, clean DIY installation.

What’s Included

• 1 × MRCOOL® 27K 5th Gen DIY Multi-Zone Condenser
  – Model: DIY-MULTI4-27HP230D-O
• 1 × 9k Wall Mount Air Handler
  – Model: DIY-09-HP-WMAH-230D25-O
• 1 × 12 Wall Mount Air Handler
  – Model: DIY-12-HP-WMAH-230D25-O
• 2 × 16 ft DIY® QuickConnect® Pre-Charged Line Sets
  – Model: DIY16-1438-O
• DIYPRO® communication cable
• Wireless remotes
• SmartHVAC WiFi/app capability
• Mounting hardware & installation manuals

Ideal Use & Room Sizing

This 2-zone MRCOOL® DIY 27K multi-zone bundle is perfect for homes that need independent temperature control in two different spaces, such as:

• A small bedroom, office, or nursery with the 9k head (up to ~200–400 sq ft)
• A large living room, master bedroom, bonus room, or open area with the 12k head (up to ~550 sq ft)

Ideal for:

• Bedrooms + living rooms
• Office + shop or studio
• Apartment or rental spaces
• Bonus rooms over garages
• Finished basements + upstairs rooms
• Small retail & professional suites
• ADUs, in-law spaces, Airbnb units

If you want quiet, ductless comfort in two rooms with one outdoor unit and DIY installation, this is the right system.

Frequently Asked Questions

Q: Do I need an HVAC license to install this?

No. The MRCOOL® DIY system is designed for homeowners. The QuickConnect® line sets are pre-charged and sealed from the factory. No vacuum pump or refrigerant handling is required.

Q: How many rooms can this system handle?

This bundle is set up for 2 zones (one 9k room and one 12k room). The condenser supports up to 4 zones total, so you can add more indoor units later if needed.

Q: What size rooms is this best for?

The 9k head is ideal for smaller rooms up to ~400 sq ft (office, small bedroom, nursery).

The 12k head works well in larger areas up to ~550 sq ft (living room, master bedroom, open plan).

Note could vary depending on ceiling height, windows, insulation and what state you are in.

Q: Are the line sets really pre-charged?

Yes. Both 16 ft DIY® QuickConnect® line sets arrive factory pre-charged with R-454B.

Q: Is this system energy efficient?

Yes. The condenser reaches up to 23 SEER2 and 9.5 HSPF2-4, which is much more efficient than older central systems, window units, or baseboard heating.

Q: Can I control it from my phone?

Yes. Use the SmartHVAC app (iOS and Android), plus Alexa and Google Assistant voice control.