Ductless Mini Split Installation: How Difficult of a DIY Job Is It?

Installing a new, traditional air conditioning system is quite the undertaking and is actually a job that’s legally required to be done by a licensed professional.

But a growing trend in home heating and cooling—the ductless mini split—is making DIY installation a reality. It requires a couple of pairs of hands and at least one day to complete, but a ductless mini split installation is a manageable project if you’re handy around the house.

Before Starting Your Ductless Mini Split Installation

There are a few things to consider before you start cutting holes in your drywall, including these terms:

  • Electrical work. A ductless mini split—for the most part—requires a dedicated 20-amp circuit. If you don’t have the electrical know-how to safely power your system, hire a professional.
  • Placement. The easiest ductless mini split installations are when the indoor air-handling units are installed on exterior walls. Installing an air-handling system on an interior wall is a much more complex project.
  • Warranty. While some can certainly manage to perform a DIY installation of a mini split system, some manufacturers, like MRCOOL, only honor their warranty if their product was professionally installed by a licensed HVAC contractor, like One Hour Heating & Air Conditioning.
  • Heights and Ladders. Homeowners typically want to install a mini split system in their bedrooms, often located on the second floor of their home. If you plan on doing this install by yourself, make sure you have a tall enough ladder to reach the upper floor of your house. If you have access to it, scaffolding is preferred over ladders for safety reasons.
  • Single Unit or System? You can purchase a ductless mini split as a single unit, which only cools one room, or a multi-room system, which runs off one outdoor condenser unit.

How to Install a Ductless Mini Split

After determining a location for your interior air-handling system and exterior condenser unit, and after a power source is secured solely for the entire system in your circuit breaker, follow these steps:

You’ll start inside first:

  1. Install the air-handling system mount. Indoor air-handling units weigh 40-50 lbs., so you’ll want to make sure the bracket hits two studs in your room. If you can’t hit a stud, a high-quality drywall anchor can do the trick.
  2. Drill the line set hole. Before boring out a hole to fit the conduit of power cords and drainpipes, drill a pilot hole from inside to outside. This hole should go where the line set connects to the indoor air-handling unit. Make sure to drill at a slightly downward angle to allow the condensate from the air-handling unit to drain outside. After drilling the pilot hole, clear out any insulation or debris and then bore the full-size hole. You’ll likely have to finish the hole by drilling from the outside of your home to the inside as well.
  3. Run the line. You’ll need someone to run the line set from the back of the air-handling unit through the hole to the outside. The person outside would then gently bend the line set to hug the house and then connect to the outdoor condenser. Once connected, wrap electrical tape around the joint to appropriately secure it.
  4. Mount the air-handling unit. Depending on your strength, this may require two people to lift and attach to the mount you’ve already installed.
  5. Install outdoor condenser unit. Attach a bracket system to the side of your home where the condenser unit will be installed. Preferably, install on the east or north side of your home to maximize cooling efficiency.
  6. Unlock the refrigerant lines. This step varies based on which brand of a mini split system you purchased. Typically, it’s a locking lever that you need to flip to connect the refrigerant lines.
  7. Power up your system. Test out your system by setting a cooler temperature. You should feel cool air blowing from your air-handling unit.
  8. Cover the line set. Your final step is covering the line set with either a plastic or metal channel. This will not only protect your line set but make the appearance of it look sleeker along your house.

How to Install a Mini Split System for Multiple Rooms

The steps above are for a single indoor air-handling unit that connects to an outdoor condenser. But you can purchase a mini split system that features multiple indoor air-handling units for more than one room. The multi-zone systems allow you to set a specific temperature in each room where an air-handling system is installed.

So, how do those additional units hook up to the outdoor condenser?

Assuming your outdoor condenser is designed for multiple air-handling units, there will be multiple connections for lines going to the inside. The rest of the installation is exactly the same as outlined above.

You will need to drill and bore a new hole in each room and then cover each individual line set that runs along the home to the outdoor condenser.

Not into DIY? Hire a Pro to Install Your Ductless Mini Split

HVAC work isn’t for everyone. That’s why it’s always a better idea to hire a licensed professional to install your ductless mini split system. The experts at One Hour Heating & Air Conditioning get your entire home feeling comfortable. Request an appointment today!