Skip to content

How to Install a DIY Mini Split System

How to Install a DIY Mini Split System

Jon Hubal
5 minute read

More and more people are switching to mini splits than ever, but professional installation can be costly – especially when added to the cost of the system itself. 

Don't worry! With many great DIY kits from established brands available, putting in your ductless system is easier than ever and can save you thousands. So, let's talk about how to install a DIY mini split system. 

DIY Mini-Split Tools Required

  • Adjustable Wrench
  • Drill and Driver
  • Hole Saw
  • Level

DIY Recommended Materials

  • Wall Brackets or Plastic/Concrete Pad (condenser)
  • Wall Brackets (evaporator)
  • Plastic Line Set Cover Kit
  • Screws

Steps to Install a DIY Mini-Split 

Step 1: Power to your Mini-Split 

First, you need to get power to the system. Mini-splits usually run on 120V or 220V Mini Split. A small system might allow you to tie into your pre-existing circuit, but the safest practice is dedicating a new breaker line to it by running a cable from the main panel to the unit. Remember to turn off the power before you begin working! Safety first, friends.

Step 2: Condenser Placement

The first step for installing your outdoor unit is finding the best location. Ideal locations should have good air circulation/ventilation, a solid base supporting the unit, and be as obscured from sight and sound as possible. Position the unit to protect it from the weather (snow, rain, sun, etc.) if you can.

Install the base for the condenser. If mounting on the ground, place the foundation pad. If wall mounting, install the condenser brackets. Either way, make sure to leave ample clearance around the unit. How much clearance should be specified in the manufacturer's manual, but at least 12" inches is recommended. 

How to Install a DIY Mini Split System

Step 3: Air Handler Placement

In the room you want air conditioning, choose an exterior wall that leads to the outside. Like the condensing unit, find an area large enough to house it and where things like furniture or shelving won't block it. The manual should list required clearances. Ensure the spot is free of wires and pipes before you make your hole. Locate the studs and fasten the bracket to them with screws. Ensure to use a level when installing your brackets; it's essential for proper function. 

Step-by-Step Guide for Wall Hole and Line Connections

Drill a 2-3" hole in the wall between the brackets. The hole is typically in the lower left or lower right-hand corner, but refer to the manufacturer's manual for your specific unit. Create a downward slope with your hole saw to allow condensation to drip down to the outside. 

Feed the refrigerant line, drain tubing, and control wiring through the wall (electrical tape helps keep them together). Connect all your lines to the circuit's outside condenser, indoor evaporator, and control wire. Please note DIY kit refrigerant lines come pre-charged. Be careful not to cut or break pre-charged lines – this is very dangerous.

Mounting the Air Handler and Covering the Refrigerant Line Set

Once everything is hooked up, it's time to mount your air handler. Replace any insulation lost in the process for better efficiency.

Last but not least, cover your refrigerant line set with some casing. Metal works great, but plastic is a more cost-effective solution for the DIY'er.

Installing a DIY Mini Split System

Step 4: Testing the DIY Mini-Split

Make sure to test your system – especially before you need it!

If you need more confidence with electrical or HVAC, having a licensed professional check never hurts to ensure it all checks out. Local inspectors are often happy to help, especially when safety is involved.

Want to DIY?

We have plenty of DIY options for you to choose from. We recommend checking out our collection of MRCOOL DIY mini splits. If you want to get more precise, you should check out our mini splits for small and medium-sized rooms. We even have it broken down into zones from single zone to 5! Start mini-split DIYing today.

Onward to your DIY Journey 

We highly recommend that if you feel uncomfortable with any of these steps, you get a trained professional to help you. Whether that be electrical or HVAC - when in doubt, call for help. 

Happy heating!

Learn More About Mini-Splits

We have your go-to articles if you want to learn more about mini-splits. Once you've fixed your leaky mini-split, it's time to see if that working mini-split actually increases your home value! Or maybe you're considering purchasing a new mini-split. First, you should figure out Mini Split Installation Guide: Where to Install Mini Split and, how to size your system for that location, the cost of running a mini-split; then check out our Best Mini Splits 2023: The Ultimate Guide

If you're looking for more technical information on mini-split, you should first learn How Do Mini Splits Work: Mini-Split 101; then read our DIY: mini-split installation guide. Finally, if you're still on the fence about mini-splits, then you need to figure out if mini-splits are right for you.

Contact The Trade Table

Have questions about DIY Mini-Split Installation or need help deciding what mini-split is perfect for you? Please feel free to contact one of our real representatives by chatting with the chat button in the bottom right, calling us at +(256) 633-6553, or emailing us at

« Back to Blog