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A Comprehensive Guide – How To Install Mini Split Ac

How To Install Mini Split Ac

Mini split air conditioners, also known as ductless mini-spilt systems, have gained immense popularity due to their energy efficiency, quiet operation, and flexibility in cooling and heating individual zones and rooms.
Whether you’re looking to control the climate of your room or office, understanding how to install a mini split AC can be valuable.
In this blog, we’ll walk you through the step-by-step process of installing a mini-split AC to help you achieve a comfortable and efficient indoor environment.
So, let’s begin.

How to Install a Split AC on an Internal Wall

• Assessing Your Needs

Before you begin the installation process, it’s crucial to assess your needs and determine the suitable location for your mini-split AC. Here’s what you should consider:

Room Size
Measure the size of the room or areas you intend to cool or heat. It’ll help you select the appropriate capacity (BTUs) of the split AC system.

Identify the ideal location for your indoor and outdoor units. Consider factors like sun exposure, structural support, and ease of installation.

Electrical Requirements
Ensure that you have access to the necessary electrical requirements, such as a dedicated circuit and the correct voltage, for the mini-split system.

• Choose the Right Split AC System

Mini-split AC comes in various configurations, such as single-zone and multi-zone systems. Here’s how you can choose the right one for your needs:

Single Zone vs. Multi-Zone
Determine whether you need to install a single-zone system for a specific room or a multi-zone system to control the different rooms independently.

Energy Efficient
Look for energy-efficient models with high SEER (Seasonal Energy Efficient Ratio) ratings to reduce energy consumption and lower utility bills.

Consider features like a Wi-Fi connection, remote control, and programmable timers for convenience and comfort.

• Gather the Necessary Tools and Materials

As you begin the installation, it’s important to gather all the much-needed tools and materials. You’ll need the following materials for installing mini split AC:

You’ll need to use the following tools:

  • Adjustable Wrench
  • Torque Wrench
  • Drill & Drill Bits
  • Hole Saw
  • Level
  • Utility Knife
  • Wire Cutter & Wire Stripper
  • Phillips Head Screwdriver
  • Flat Lay Screwdriver
  • Level
  • Safety Glasses
  • Work Gloves
  • Ladder


  • Mounting Brackets
  • Refrigerant Line Set
  • Electrical wire
  • Insulation
  • Copper Tubing
  • A Condensate Pump (if needed)

• Split Air Conditioner Installation Manual

How To Install Mini Split Ac-min

Installing the Indoor Unit
Now, let’s dive into the installation process:

Mark the Location
Choose the installation location for the indoor unit, ensuring the level and center of the wall. Mark the position for the wall sleeve and refrigerant line hole.

Install the Wall Sleeve
Drill a hole for a wall sleeve and secure it in a place using the appropriate anchors and screws. Ensure a watertight seal around the sleeve.

Mount the Indoor Unit
Attach the mounting plate on the wall and install an indoor unit into the plate. Connect the refrigerant lines and electrical wiring according to the instructions of the manufacturers.

Insulate the Refrigerant Lines
Wrap the refrigerant lines with the insulation to prevent condensation and maintain energy efficiency.

• Outdoor Unit Installation

Outdoor Unit Installation-min

Let’s move on to the outdoor unit installation:

Find the Location
Find the hole you drilled for the mounting plate for the indoor unit and place the outdoor unit within 50 feet (15m) so the piping and cable can easily be attached.
Make sure your outdoor unit is leveled and well-ventilated, away from direct sunlight and obstruction.

Connect the Refrigerant
Connect the refrigerant lines from the indoor unit to the outdoor unit, following the manufacturer’s guidelines. Use the torque wrench to tighten up the flare nuts.

Attach Electrical Wiring
Connect the electrical wiring from the indoor unit to the outdoor unit, following the provided wiring diagram.

Tip: We recommend hiring an electrician if you aren’t trained to handle high-voltage current.

• Pressure Testing and Vacuuming

To ensure that the system works smoothly and efficiently, the next step is to perform pressure testing and vacuuming.

Pressure Test
Pressurize the refrigerant lines for the detection of any leaks. You can use a leak detection solution of a refrigerant leak detector to identify any leaks in the system.

Vacuum Pump
Use a vacuum pump to remove air and moisture from the refrigerant lines. This step is crucial for the system’s functionality and longevity. Allow the vacuum to run for at least 30 minutes.

• Electrical Connections and Final Checks

Check Power Supply
Connect the outdoor unit to the dedicated electrical circuit, ensuring proper grounding and adherence to local electrical codes.

Test the System
Turn on the mini-split AC and test it in both cooling and heating modes. Verify that the system operates smoothly and maintains the desired temperature.

Insulate and Seal
Insulate the refrigerant lines and seal any gaps around the indoor and outdoor units to prevent air leakage and maintain energy efficiency.

• Maintenance and Troubleshooting

To keep your mini-spilt AC in top condition, consider the following maintenance and troubleshooting:

Regular Cleaning
Clean and replace air filters as recommended by the manufacturer. Clean the outdoor units’ coils and ensure proper airflow.

Professional Maintenance
Schedule annual maintenance by a skilled and professional HVAC technician to inspect and service the system, including level check of refrigerant lines and cleanliness of condensers and evaporator coils.

If you encounter any issues in your mini split AC, consult the manufacturer for a troubleshooting guide or contact a professional technician.


Installing a mini-split air conditioner can be a rewarding DIY project that enhances your indoor comfort and energy efficiency. With the right tools, materials, and careful attention to detail, you can enjoy the benefits of a well-installed mini-split AC system for years to come. However, if you’re not comfortable with electrical work or refrigerant handling, it’s advisable to seek professional installation services to ensure safety and optimal performance.

HOMERIGHT Heating and Air Conditioning Inc. is the leading company that provides mini split installation service and assistance in keeping your HVAC system in peak shape. So, if you need to inspect and maintain your mini split AC, contact us now to experience the difference.

Frequently Asked Questions 


How Much Does It Cost To Install A Mini-split Ac?

On average, homeowners have to spend $3000 for a mini-split AC installation.

How To Install Mini–split Ac In The Garage?

Determine the Size Calculate the heating and cooling capacity needed for your garage based on its size and insulation. Choose an appropriately sized mini-split unit. Select Location Decide where to mount the indoor unit in your garage, ensuring that it's away from obstruction and offers even distribution of air. Install Wall Sleeve Drill a hole in the wall sleeve and mount it securely on the wall. Make sure it's leveled and properly sealed. Connect Refrigerant Lines Carefully connect the refrigerant lines from the indoor unit to the outdoor unit. Electrical Wiring Connect the electrical wiring from the indoor unit to the outdoor unit, following the wiring diagram. Mount the Outdoor Unit Place the outdoor unit on the stable platform or mounting brackets in the well-ventilated area outside of your garage. Pressure Testing and Vacuuming Perform a pressure test and use a vacuum pump to remove air and moisture from the refrigerant lines. Final Checks Test the system in both cooling and heating modes to ensure it is functioning correctly. Insulate the refrigerant lines and seal any gaps around the indoor and outdoor units.

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