How to Install a Mini Split System AC - 10 Easy Steps

A DIY mini split system AC is a cost-effective and energy-efficient way to keep your home comfortable during hot and humid weather, especially if you don't have ductwork. DIY systems are easy to install, making them a popular choice for homeowners who prefer to do the work themselves.

In this article, we will guide you through the steps of installing DIY ductless mini split systems, ensuring a safe and hassle-free installation.

Please keep in mind that this is only for DIY mini splits. Please consult a professional to install conventional mini splits.

DIY ductless mini split installation is straightforward and ideal for DIYers. It is cheaper to install your own system. Also, DIY compact mini splits can be installed more quickly and easily than other air conditioning appliances.

MRCOOL's DIY mini split systems are designed for do-it-yourself installation. Because they come with pre-charged refrigerant lines, they don't require you to hire an HVAC technician to assist with the installation.

However, a conventional ductless mini split is not designed for do-it-yourself installation. If you have experience, you may be able to install some pieces on your own, like the indoor air handler or the outdoor condenser unit, but the average DIY handyman should not handle this task by themselves. A DIY-er cannot handle refrigerant or refrigerant lines without a license or certification. Additionally, electrical wiring can pose a challenge and usually requires a certified electrician. That means that most conventional mini split installations require professional assistance.

1. Mini split system AC unit
2. Mounting bracket
3. Power drill
4. Anchors & screws
5. Level
6. Refrigerant line set & piping
7. Electrical wire
8. Wire cutters
9. Electrical tape
10. Line wrenches

Choose a location for the mini split indoor unit. The indoor air conditioning unit, also called the air handler or interior unit, should install high up on a wall where you can maintain the manufacturer's recommended amount of clearance. You typically want to install the indoor unit about six feet above the floor and at least six inches below the ceiling. The air handler circulates the cool air, so you want to keep it free of any obstacles, like a light fixture or shelving and away from flammable items like curtains. The indoor air handler is commonly installed on an exterior wall. Being close to the exterior wall allows for a more direct connection to the outdoor unit, but they can work on interior walls as well.

The location should be somewhat near the outdoor unit with enough space to run the refrigerant line set between them.

Locate studs that can support the weight of the unit and make sure there are no pipes or wiring where you plan to install the air handler. Using a power drill, screws, and anchors, install the mounting bracket on the wall where you plan to install the mini split indoor unit. Ensure the bracket is level and secured with anchors designed to hold the weight of the indoor unit before moving on to the next step.

Cut a hole into the wall to allow the refrigerant lines, drainage pipe, and signal cable to pass through. This hole may range from 2-3 inches in diameter, but the size needed depends on the size of the lines. This hole should avoid the location of the studs.

Bundle the line set and other piping together with electrical tape, making sure that the drain pipe is at the bottom. Do not tape the ends of the piping.

If you are installing a DIY mini split system, do not cut the refrigerant lines as this can be dangerous and ruin your system. This poses a safety hazard as the refrigerant can cause burns to the skin. It also ruins the line set. When prepping the line set, you may need to remove some packaging insulation or bend the piping to pass through the hole in the wall. Be careful not to damage the piping in the process.

If you are using refrigerant lines that need to be cut and charged, contact a certified HVAC technician to complete this step. A certified professional must cut and charge refrigerant lines. Many areas have codes requiring refrigerant to be handled by a certified HVAC technician and it can be dangerous if not installed properly.

Feed the pre-charged line sets, wiring, and drainage tubes through the hole created in the wall while lifting the indoor unit. You may need another person to assist you with this step as it can be difficult for a single person to manage.

Hang the indoor unit on the mounting bracket, ensuring it is level. Secure it in place following the manufacturer's instructions.

The outdoor condenser unit, sometimes called the outdoor unit or exterior unit, typically sits in an open space, either on the ground outside or on a wall mount bracket. If you plan to install it on the ground, it must secure to a solid, level base. You can use a pad, such as a concrete pad or one designed specifically for this purpose. Additionally, avoid installing the outdoor unit near any combustible gas.

Other places to avoid include (but are not limited to):

• Areas where the condenser can be hit by falling ice or snow.
• Dense shrubbery or other vegetation that can impact air flow.
• Areas where plants or animals could be harmed by the discharge of hot air.

Connect the refrigerant line set and other piping to the outdoor unit following manufacturer's instructions. Tighten the connections securely and ensure there are no leaks.

Next, anchor the outdoor unit to the ground or wall mounted bracket.

Please contact a professional and certified HVAC technician if you have any concerns about handling refrigerant. Refrigerant lines can pose a hazard if cut, damaged, or leaking. If you notice any of these issues, please stop what you are doing and contact a certified HVAC professional.

**Before performing any electrical work, turn off all power to the unit.**

Additionally, we recommend having a local electrician complete this step for you. If you are inexperienced with electrical wires or electrical connections, the wrong wiring can damage the unit and cause a safety hazard as well as a fire risk.

The electrical wiring should connect the indoor and outdoor units in a way that follows manufacturer's instructions as well as local and national codes and regulations.

After completing the installation, perform any necessary safety checks. This may include checking grounding work, checking for electrical leakage, gas leak checks, and any other related safety checks. If the installation passes these checks, you can move on to the next step.

Once the system is fully connected, turn it on and test it. Ensure it is functioning correctly, and that the indoor and outdoor units are communicating with each other. Make any necessary adjustments or repairs before proceeding to the next step.

Congratulations! You have successfully installed a ductless mini split system air conditioner in your home. Enjoy the cool and comfortable air during the hot and humid months.

Installing a DIY mini split air conditioner can be a rewarding and cost-effective project for homeowners. By following these steps and taking the necessary safety precautions, you can ensure a successful installation and enjoy the benefits of an energy-efficient and comfortable home.

However, if you are not comfortable with any step of the installation process, it's best to hire a professional to ensure your safety and the proper functioning of the system.

Unlike central systems, which can cool a whole building, ductless mini split air conditioning and heat pump units can only condition zones. They typically don't work well for cooling a whole building. Another downside can be the cost of installation. You need an HVAC professional to install a ductless mini split system if it's not DIY and they can charge anywhere from $75 to $150 an hour. Additionally, their upfront cost is almost as high as a central air conditioning system, though they save money on installation costs as you don't have to install expensive ductwork.

MrCool is the top name for DIY mini split installation. Their company offers the DIY series of mini split air conditioners and heat pumps which the average DIY handyman can install himself! These mini split units are easily installable and boast high SEER ratings and more zones than before! They also avoid the need to hire and wait for a professional.

Disclaimer: this is meant to serve as a general guide only and is not meant to substitute the advice or experience of an HVAC professional or the guidelines of the manufacturer's instructions. Installation can vary depending on each individual manufacturer and type of unit. Please consult the manufacturer's instructions for a more detailed guide to installing their mini split air conditioner. If you are unsure, inexperienced, or have purchased a conventional mini split, please contact an HVAC professional to help you in your mini split installation.