MRCOOL DIY 5th Gen 36,000 BTU 5-Zone Ductless Mini Split Heat Pump System (9K + 18K Air Handlers with 25 ft QuickConnect Line Sets)

MRCOOL DIY 5th Gen 36,000 BTU 5-Zone Ductless Mini Split Heat Pump System (9K + 18K Air Handlers with 25 ft QuickConnect Line Sets)

The MRCOOL DIY® 5th Gen 36,000 BTU 5-Zone Multi-Zone Bundle is a comprehensive HVAC solution designed to deliver personalized heating and cooling across multiple areas of your home or workspace, while still offering true DIY installation convenience. This system combines a high-capacity 36,000 BTU outdoor condenser with two indoor wall-mounted air handlers — a 9,000 BTU unit for smaller rooms and an 18,000 BTU unit for larger spaces — providing versatile zoning capabilities for enhanced comfort and efficiency.

Installation is simplified through the use of QuickConnect® pre-charged line sets, which come factory sealed with refrigerant and eliminate the need for vacuum pumps or other professional HVAC tools. The included 25-ft line sets offer flexibility in unit placement and make the installation manageable with basic tools, saving both time and cost.

Each indoor unit operates independently, allowing you to set different temperatures in each zone. The system’s advanced DC inverter technology ensures smooth, efficient, and quiet operation throughout the year, reducing energy consumption while maintaining optimal comfort. Wireless remote controls make it easy to manage each zone, and smart control readiness enables remote access and integration with smart home systems.

Built with durability in mind, the outdoor condenser features corrosion-resistant construction that withstands varied environments and weather conditions. Backed by robust manufacturer warranty coverage, this MRCOOL DIY® multi-zone system bundle is ideal for homeowners seeking professional-grade zoned heating and cooling with true DIY installation ease.

Features

• Multi-zone heating and cooling for customized comfort across rooms

• Includes one 9,000 BTU wall-mounted indoor air handler

• Includes one 18,000 BTU wall-mounted indoor air handler

• DIY-friendly installation with pre-charged 25 ft QuickConnect® line sets

• Uses R-454B refrigerant

• Quiet, energy-efficient DC inverter technology

• Independent wireless remote controls for each indoor unit

• Smart control capable for remote app and voice assistant integration

• Durable, corrosion-resistant outdoor condenser design

• Ideal for a range of residential multi-room HVAC needs

Specifications

What’s Included

✔ 1 × 36,000 BTU 5-Zone DIY Condenser — 

DIY-MULTI5-36HP230D-O

• 36,000 BTU 5th Gen DIY® multi-zone condenser, 208/230V
• Supports up to 5 indoor zones
• High efficiency: up to 23 SEER2, 9.9 HSPF2-4
• Factory-charged with R-454B, a more eco-friendly, future-ready refrigerant
• Compatible with 5th Gen MRCOOL DIY air handlers (6K–36K)
• Uses DIY Quick-Connect® ports—no vacuuming, brazing, or flaring
• SmartHVAC® App + Amazon Alexa + Google Assistant
• Quiet rotary inverter compressor
• Gold Fin® corrosion-resistant coating
• Ideal for total coverage up to about 1,500 sq. ft. (depending on layout and climate)

✔ 1 × 9,000 BTU DIY Wall-Mount Air Handler — 

DIY-09-HP-WMAH-230D25-O

• 9,000 BTU wall-mount indoor unit, 208/230V
• Comfort coverage for rooms up to ~400 sq. ft.
• Great for bedrooms, home offices, nurseries, and smaller bonus rooms
• Works with 1/4” × 3/8” R-454B Quick-Connect line sets
• Multi-speed fan with Quiet Mode for nighttime use
• Follow Me® function uses the remote’s sensor for accurate comfort at your location
• Dry Mode to help pull humidity out of the air
• Built-in WiFi, SmartHVAC® app control, plus Alexa & Google voice control
• Includes DIYPRO® cable to eliminate traditional electrical conduit

✔ 1 × 18,000 BTU DIY Wall-Mount Air Handler — 

DIY-18-HP-WMAH-230D25-O

• 18,000 BTU wall-mount indoor unit, 208/230V
• Ideal for larger spaces up to 800 sq. ft.
• Perfect for living rooms, dens, bonus rooms, and finished basements
• Pairs with 1/4” × 1/2” R-454B DIY line sets
• High efficiency, inverter-driven performance with ENERGY STAR® certification
• Ultra-quiet indoor operation with five fan speeds
• Dry Mode and Follow Me® remote comfort
• WiFi built-in for SmartHVAC® app, Alexa, and Google Assistant
• Includes DIYPRO® cable for a cleaner, simpler electrical run 

✔ 1 × 25ft R-454B Line Set (1/4” × 3/8”) — 

DIY25-1438-O

• 25-foot pre-charged R-454B Quick-Connect® line set
• Sized for 6K, 9K, and 12K MRCOOL DIY indoor units
• 1/4” liquid line × 3/8” suction line
• Factory vacuum-sealed and charged—no vacuum pump required
• Quick-Connect® threaded fittings that lock to the DIY condenser and air handler

✔ 1 × 25ft R-454B Line Set (1/4” × 1/2”) — 

DIY25-1412-O

• 25-foot pre-charged R-454B Quick-Connect® line set
• Sized for 9K, 12K, and 18K MRCOOL DIY indoor units
• 1/4” liquid line × 1/2” suction line
• Pre-charged and sealed with R-454B
• Quick-Connect® fittings for fast, no-vac DIY installation

Why This MRCOOL 36k 9K + 18K + 25ft Line Set Bundle Works So Well

This specific bundle configuration is ideal when:

• You want one smaller zone (bedroom/office) and one larger zone (living room/den/basement)
• The indoor units need to be placed further away from the outdoor condenser
• You want the flexibility of 25-foot line sets from day one, without needing extensions

It’s a killer fit for:

• Older homes without ductwork
• Additions, upstairs/downstairs layouts, or split-level homes
• ADUs, in-law suites, and rentals where you need two major comfort zones
• DIYers wanting multi-zone comfort with minimal disruption and wiring

Key Benefits of the DIYM236HPW02D07 Bundle

• True DIY installation using pre-charged, vacuum-free R-454B line sets
• Future-proof refrigerant choice (R-454B instead of R-410A)
• Zoned comfort with independent 9K and 18K control
• Longer 25ft line sets for flexible indoor unit placement
• Smart controls via app and voice (Alexa & Google)
• Quiet operation suitable for bedrooms and living spaces
• Expandable multi-zone platform – add up to 3 more indoor units later
• Strong warranty backing from MRCOOL with Care Program eligibility

Frequently Asked Questions (FAQ's)

1. Can I install this MRCOOL DIY bundle myself?

Yes. This system is designed for DIY installation with pre-charged R-454B Quick-Connect® line sets, so you don’t need a vacuum pump or to handle refrigerant.

2. How many zones can this system support?

The DIY-MULTI5-36HP230D-O condenser can support up to 5 indoor units. This bundle uses a 9K and an 18K, leaving room to add up to three more zones later.

3. What room sizes are the 9K and 18K air handlers best for?

• 9K air handler: up to about 400 sq. ft.
• 18K air handler: up to about 800 sq. ft.
  These estimates assume average insulation and ceiling heights.

4. Why are 25ft line sets important?

The 25ft DIY25-1438-O and DIY25-1412-O line sets give you more flexibility to locate the indoor units further from the outdoor condenser, which is helpful for side yards, back patios, and longer wall runs.

5. Do I need to vacuum the line sets before opening the valves?

No. The line sets are factory vacuumed and pre-charged, so you simply connect, torque to spec, and open the valves according to the MRCOOL instructions.

6. What refrigerant does this system use?

This 5th Gen MRCOOL system uses R-454B, which is the newer, lower-GWP replacement for R-410A.

7. Is this system quiet enough for bedrooms?

Yes. Both air handlers feature Quiet Mode and low sound levels suitable for sleeping areas and living spaces.

8. Does the system dehumidify as well as cool?

Yes. Use DRY MODE to focus on humidity removal while still keeping the space comfortable.

9. Can I control each zone separately?

Yes. Each indoor unit has its own remote and its own WiFi control, so you can set different temperatures and schedules per room.

10. Is smart home control included?

Yes. The air handlers are compatible with the SmartHVAC® App, Amazon Alexa, and Google Assistant.

11. Will my warranty be valid if I buy from MRCOOL Direct?

Yes. MRCOOL Direct is an authorized MRCOOL dealer, so your warranty is fully supported when installed and registered correctly.

12. What warranties come with this bundle?

Typically:

• 5-Year Parts Warranty
• 7-Year Compressor Warranty
• Limited Lifetime Replacement Warranty when enrolled in MRCOOL® Care (subject to MRCOOL terms).

13. Is this setup good for a small home or duplex?

Yes. A 9K + 18K + 36k condenser is an excellent 2-zone configuration for smaller homes, duplexes, apartments, or main living + bedroom setups.

14. Do I need an electrician for the outdoor unit?

If you are not comfortable working with 230V circuits and breakers, you should hire a licensed electrician to complete the power connection.