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NEW R-454B Refrigerant

MRCOOL DIY® 5th Gen 18,000 BTU Multi-Zone Mini Split Condenser 230V, DIY-MULTI3-18HP230D-O

MRCOOL DIY® 5th Gen 18,000 BTU Multi-Zone Mini Split Condenser 230V, DIY-MULTI3-18HP230D-O

Regular price $1,555.00
Sale price $1,555.00 Regular price $1,974.85
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🔀 Up to 6 Zones
🛠️ DIY Install Ready
🏠 Whole-Home Zoning

SKUDIY-MULTI3-18HP230D-O

TypeMulti-Zone Condenser

Refrigerant Type: R-454B

✅ This item is in stock!

More than 30 available

Estimated Delivery: December 17 – December 19

Based on order date & typical delivery times.
• Orders Typically ship within 2 business days

Don't forget your pre-charged line sets.
Each zone/air handler will need its own length — click here to select.
16'25'35'41'50'60'66'75'
MRCOOL Pre-Charged Line Set
View full details

Have questions or need help selecting the perfect Mini Split system?

Talk with our expert HVAC team members now for assistance!!

PRODUCT DESCRIPTION

MRCOOL® DIY 5th Gen 3-Zone Multi-Zone Mini Split Condenser

Model: DIY-MULTI3-18HP230D-O

Introducing the all-new 5th Generation MRCOOL® DIY® Multi-Zone Mini Split Condenser, engineered for maximum comfort, efficiency, and convenience. With the ability to cool and heat multiple zones independently, this system is ideal for small homes, apartments, home offices, or workshops. Thanks to its DIY® Quick Connect® pre-charged line sets and intuitive design, you can install it yourself without the need for special tools or HVAC certification.

Key Features

  • DIY Installation: Tool-free, vacuum-free setup with no prior experience required
  • DIY® Quick Connect® Line Sets: Pre-charged with environmentally friendly R-454B refrigerant
  • Smart HVAC Control: Control each zone via the MRCOOL® SmartHVAC® app, Amazon Alexa, or Google Assistant
  • DIYPRO® Cable: Durable armored cable eliminates the need for electrical conduit
  • Gold Fin® Condenser: Corrosion-resistant coating ideal for coastal environments
  • Industry-Leading Warranty: 7-Year compressor, 5-Year parts, and Limited Lifetime Replacement Warranty with registration in the MRCOOL® Care Program
  • Certified Quality: Intertek listed 5031495 for tested safety and performance

Air Handler Compatibility

This condenser supports up to three indoor air handlers with a maximum combined capacity of 24,000 BTU. Available air handler sizes: 6K, 9K, and 12K BTU.

Examples of Compatible Combinations:

  • 6K + 6K + 12K (24,000 BTU)
  • 6K + 9K + 9K (24,000 BTU)
  • 6K + 6K + 9K (21,000 BTU)
  • 6K + 9K + 6K (21,000 BTU)
  • 9K + 9K (18,000 BTU – one port unused)
  • 6K + 12K (18,000 BTU – one port unused)

Recommended Wire Sizing

  • Recommended: 12 AWG copper wire – safe for 18A minimum circuit ampacity
  • One Size Smaller (14 AWG): Not recommended – may overheat under full load and violate electrical code
  • One Size Larger (10 AWG): Offers lower voltage drop and extra safety margin

Ideal Coverage Area

Perfect for spaces ranging from 750 to 1,100 sq. ft., depending on your climate zone and insulation quality.

Note: Always verify system configuration before purchasing. Specifications may change during production. Images may be representative only.

Buy from MRCOOL DIY Direct — the USA’s most trusted HVAC dealer for do-it-yourself heating and cooling solutions.

SPECIFICATION & DIMENSIONS

Specification Details
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, 1 Phase
Minimum Circuit Ampacity 18 A
Maximum Fuse 25 A
Refrigerant Type R-454B
Refrigerant Charge 67.37 oz
Line Set Sizes 3/8" Liquid x 5/8" Gas
Net Dimensions (WxDxH) 37.24" x 16.14" x 31.89"
Net Weight 122.80 lbs
Recommended Wire Size 12 AWG (recommended for 18A load)
One Size Smaller (Risk) 14 AWG – May overheat or fail to meet code under full load
One Size Larger (Benefit) 10 AWG – Increased safety margin and reduced voltage drop

Rated 4.7 / 5 Stars
4700+ Verified Reviews

Comfort That Speaks for Itself

See why homeowners and pros alike trust MRCOOL DIY systems to deliver comfort, savings, and easy installation.

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi

Each of our three MRCOOL air handlers runs perfectly quiet, and it’s awesome being able to control them separately. Installation videos made the whole process doable

Cindy M., Texas

I installed my MRCOOL Universal nearly two years ago. It’s been maintenance-free, super efficient, and I love how consistent the airflow is through my existing ducts

Dave K., Georgia

Our double-wide doesn’t have room for a big air handler, so the MRCOOL wall unit was perfect. Easy install, clean look, and it cools like a champ

Amy R., Florida

The quotes for replacing our old packaged unit were crazy. Installed a MRCOOL 18K system instead — now the living room and bedrooms stay cool all summer without breaking the bank.

Dean L., Alabama

You’d never know it’s running — it’s that quiet. The unit heats our entire single-wide better than the old furnace ever did.

Brenda C., Oklahoma

The MRCOOL mini-split doesn’t take up much space, which is perfect for our tight hallway. It cools faster than I expected and doesn’t trip the breaker like our old window unit.

Lori B., Mississippi