MRCOOL DIY 5th Gen 27K 2-Zone Mini Split System 9K + 12K R-454B Pre-Charged 16 ft + 25 ft Line Sets DIY-MULTI4-27HP230D-O

MRCOOL DIY 5th Gen 27K 2-Zone Mini Split System 9K + 12K R-454B Pre-Charged 16 ft + 25 ft Line Sets DIY-MULTI4-27HP230D-O

The MRCOOL DIY 5th Gen 27K 2-Zone Mini Split System delivers efficient, customizable heating and cooling for two separate spaces using one powerful outdoor condenser. Designed for easy DIY installation, this system includes two indoor wall-mount air handlers — a 9,000 BTU unit for smaller rooms and a 12,000 BTU unit for larger living areas — plus both 16 ft and 25 ft pre-charged QuickConnect® line sets, eliminating the need for vacuuming or refrigerant charging.

Equipped with eco-friendly R-454B refrigerant and advanced inverter technology, this mini split system provides reliable performance with up to 23 SEER2 cooling efficiency and 9.5 HSPF2-4 heating efficiency. Each zone operates independently, offering tailored comfort in bedrooms, home offices, finished basements, or open living spaces.

Smart controls allow for flexible adjustments via included remotes, the SmartHVAC app, or voice-enabled assistants like Amazon Alexa and Google Assistant. Quiet operation and advanced dehumidification (Dry Mode) help maintain a comfortable indoor environment year-round without intrusive noise.

This system uses only two of the four possible zones supported by the condenser, giving homeowners the option to expand their comfort solution later by adding more indoor units. Whether upgrading comfort or completing a new installation, this 2-zone mini split system is engineered to make DIY installation manageable and efficient.

Features

• DIY® QuickConnect® pre-charged line sets included (16 ft and 25 ft) — no vacuum or refrigerant tools needed

• Independent temperature control for two rooms

• Eco-friendly R-454B refrigerant

• SmartHVAC app compatibility and voice assistant support

• Quiet indoor operation with energy-efficient inverter technology

• Expandable condenser supports up to four 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 Set and DIY25-1438-O - 25 ft Pre-Charged Line Set

• Length: 16 ft and 25ft 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
• 1 × 16 ft DIY® QuickConnect® Pre-Charged Line Sets
  – Model: DIY16-1438-O
• 1 x 25 ft DIY® QuickConnect® Pre-Charged Line Sets
  – Model: DIY25-1438-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 and 25 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.