How to Install a Mini Split AC Unit (A Step-by-Step Guide)

How to Install a Mini Split AC Unit

The shift towards energy-efficient, compact, and versatile air conditioning units has gained momentum over the years. One such innovation is the mini split AC. For homes without ductwork or individual room temperature control, mini-split ACs offer numerous benefits, including energy efficiency, quiet operation, and adaptability. 

This article walks you through a comprehensive step-by-step guide on how to install a mini split AC unit.

Step 1: Choose the Right Mini Split AC Unit for Your Needs

  • Size Matters: The unit’s capacity should be in accordance with your room’s size.
  • Brands: While choosing from popular mini split AC brands, consider the warranty, customer reviews, and after-sales service.

Step 2: Prepare Your Home for Installation

  • Scout for Location: Ensure the chosen location is free from obstacles and allows for efficient airflow.
  • Safety First: Turn off the main power and clear the installation area.

Step 3: Install the Outdoor Unit

  • Positioning: Place the unit on a flat, elevated surface like a concrete slab or wall brackets.
  • Ensure Clearance: Ensure ample space around the unit to ensure proper ventilation.

Step 4: Install the Indoor Unit

  • Wall Mounting: Mark the spot where the mounting bracket will be affixed. Make sure it’s level. Drill holes and affix the bracket.
  • Pass-Through Hole: Drill a hole (usually about 3 inches) for the refrigerant pipes, cables, and drain hose.

Step 5: Connect the Refrigerant Lines and Electrical Wires

  • Run the refrigerant lines, connecting the indoor and outdoor units.
  • Make sure the lines are not twisted or bent sharply.
  • Connect the electrical wires following the manufacturer’s instructions carefully.

Step 6: Test the Unit and Ensure It's Working Properly

  • Turn the power back on.
  • Test the unit by running it in various modes to ensure smooth operation.
  • Check for any unusual noises or vibrations.

Frequently Asked Questions

How does a Mini Split AC Unit work?

Using refrigerant, a mini split AC unit transfers heat between the indoor and outdoor units. In cooling mode, it extracts heat from inside the room and disperses it outdoors, while in heating mode, it does the opposite.

What are the benefits of a Mini Split AC Unit?

Mini-splits offer flexible placement, increased energy efficiency, and individualized room control and are an excellent solution for homes without ductwork or spaces where installing ducts would be impractical.

How is a Mini Split AC Unit installed?

Installation involves mounting the indoor unit on an interior wall and the outdoor unit on a base outside. The two teams are connected using refrigerant lines, electrical cables, and a condensate drain line through a small hole in the wall.

Are there any maintenance tips for Mini Split AC Units?

Regularly clean or replace the filters, check the outdoor unit for debris, ensure the condensate drain isn’t blocked, and get a professional service check annually.

In what scenarios is a Mini Split AC Unit most beneficial?

Mini-splits are ideal for home additions, converted garages, older homes without ducts, or areas that need individual temperature control, such as a sunroom.

Can Mini Split AC Units provide both heating and cooling?

Yes, many mini split units are heat pumps, which can heat and cool a space. However, it’s essential to ensure the model you’re considering has this capability if it’s a desired feature.


Installing a mini split AC unit can seem daunting, but it can be a rewarding DIY project with the right tools and guidance. However, ensure you follow all safety precautions. If you encounter issues or feel uncomfortable at any stage, it’s wise to contact a qualified HVAC contractor

Troubleshooting common problems—like unusual sounds or inefficiency—can often be resolved by checking connections, ensuring proper positioning, or consulting the manual. Yet, for peace of mind and assurance, professional installation is recommended.

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Momentum AC Services Inc is a family-owned HVAC company in the Tampa area. We offer fast installation of all major brands of air conditioning units with no hidden costs or surprises. Momentum AC will work hard to make sure your new unit is installed on time and that it runs smoothly for years to come. 

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