DIY Mini Split Installation

I spend a lot of time in my workshop, so I decided to perform a DIY mini split installation for temperature and humidity control in my workshop.  The Mr Cool DIY 18,000 BTU 1.5 Ton Ductless Mini-Split Air Conditioner and Heat Pump (model:  DIY-18-HP-230A) fit my needs perfectly.


Tools I Used for this DIY Mini Split Installation:



FREE DIY PLANS – Grab Your Free DIY Plans for this Project at the bottom of this post.


DIY Mini Split for Workshop and Home Office

My workshop is a separate building from my main house and it has 2 levels.  The first level is my workshop and the second level is my home office.  I decided it was best to remove the original HVAC system.  It was very old and not worth the cost of repair.

Home Office

I decided to install a DIY mini split in my home office during the fall of 2016.  After many hours of research of DIY min split installation articles, I installed the Mr Cool DIY 18,000 BTU 1.5 Ton Ductless Mini-Split Air Conditioner and Heat Pump (model:  DIY-18-HP-230A) for my home office.  I did not worry about cooling or heating my downstairs workshop because winter was near.  Additionally, I decided to test the performance of the ductless mini split in my home office before deciding on a cooling and heating system for my workshop.


I was pleasantly surprised with the performance of the DIY mini split in my home office and decided to purchase the same unit for my workshop.  I learned how to install a mini split during the first installation, so I decided to make a video and document my second mini split installation.



Why this DIY Mini Split

I chose the Mr Cool DIY ductless mini split (model DIY-18-HP-230A) because of the price, features, size, and it is 100% DIY.


MrCool DIY mini splits are DIY units as the name implies.

The refrigerant lines are pre-charged with R410A refrigerant, which eliminates the need for a professional installation.

The Mr Cool mini split install process is straightforward for an intermediate to advanced DIY’er – check out my video at the top of this post.  This DIY mini split installation was relatively straightforward and the instructions were well written.


The total price for the Mr Cool DIY Mini Split Installation was $1,457.00 plus $50.00 for the wall mount bracket.  The total price was $1457.00 before tax as of 2017.

I received multiple quotes from HVAC professionals on installing a similar unit to the Mr Cool DIY-18-HP-230A and the prices ranged from 2.5 to 3 times more than the Mr Cool DIY mini split.  There are certainly many reasons and advantages to hiring an HVAC professional to install a mini split or conventional system.  This was my workshop and home office; therefore, I decided it was worth the risk to buy the DIY mini split unit and install it myself.  If I were faced with the same decision for my home, I probably would have chosen to hire an HVAC professional.  Reputable HVAC professionals guarantee their installation, support manufacturer warranties, and provide service agreements.

Mini Splits versus traditional central HVAC systems are beyond the scope of this article.  If you are faced with this decision, I encourage you research these topics and decide what is best for your situation and environment.

Mr Cool DIY Features

The features of the Mr Cool DIY mini split supported my needs even though it may not have the features of more expensive brands.  Below are the features I like most:

  • Dual heat pump and AC unit.
  • Refrigerant leakage detection system ensures the system operates efficiently without degradation due to corrosion.
  • WiFi adapter allows it to be connected to the Internet and controlled remotely via an app.
  • Warranty: 7 year compressor and 5 year parts.
  • Low Noise:  57dBA decimal rating.
  • Variable Speeds
  • Louver Position Memory and Swinging capability.

Mr Cool DIY Mini Split Size

There are different Mr Cool DIY mini split size models for different size areas.  The Mr Cool DIY mini split model I purchased and installed covers 850 square feet.  I was concerned with the 18′  high ceilings in my workshop, so I purchased this unit which covers more square feet than my workshop.  My workshop is approximately 600 square feet.

How to Install a Ductless Mini Split Overview

Below are the main steps I performed to install the Mr Cool DIY mini split.  These steps provide a good overview of the process.  This process is not meant to replace the manufacturers instructions; rather, it is a supplemental aid.  Be sure to check out my video for more detail.


Step 1:  Unboxing

I ordered the Mr Cool DIY mini split online and it arrived in 2 boxes:  the outside condenser unit and the inside unit.  Both boxes were packaged very well.  I inspected each part for damage very carefully.  The refrigerant hose is connected to the inside unit and wrapped with a plastic coating and tie wraps.

How to Install a Ductless Mini Split - Unboxing

Step 2:  Assemble Wall Bracket

I purchased the wall mount for the outside condenser unit separate.  I chose the wall mount option rather than mounting the unit on a slab.  It is easier to assemble the wall mount bracket before installation rather than in the middle of the installation.