How to Install a Mini Split

A ductless mini split heat pump or air conditioner can be a great choice for heating and cooling an older home with no existing ductwork, supplementing a ducted system in rooms that are not adequately heated or cooled, and for adding comfort to room additions or a converted space (such as a basement, garage or attic).

DIY Mini Split Installation

A ductless air conditioning system consists of an outdoor unit and an indoor unit connected by refrigerant pipe and electric cable, which enter the home through a small hole in the wall. Installation by a professional installer is quick and minimally disruptive, providing you with flexibility and comfort without compromises. While you might be tempted to tackle this DIY mini split installation yourself, we recommend that this work be done by your local Carrier expert who is trained to know how to install a mini split ductless system.

For example, indoor units for a ductless system are available in wall mount, ceiling mount, in-ceiling, and floor mount options. The indoor unit needs to be properly secured to an interior surface, often with a specially designed mounting bracket. An improperly installed condensate line on the indoor unit can leak condensate on interior surfaces.

Another common misperception about ductless systems is that the indoor unit needs to be mounted on an exterior wall for venting purposes. However, this is not the case. Like ducted split systems, heat energy from indoor air is absorbed into the refrigerant which circulates through connected tubing to the outdoor condensing unit where it is released into the air outside.

Installing and connecting the refrigerant lines and charging the system to the correct pressures are critical to ensuring effecting and efficient performance.

For these reasons and many more, hiring a professional is the best way to ensure the comfort – and safety – of you and your loved ones.

Benefits of Mini Split Installation by a Professional

While the absence of ductwork might make mini split installation seem like a great DIY project, that's far from the truth. Sure, it may be a little less complicated than installing forced air AC systems, but there are still a number of reasons why you should contact a professional to install your ductless AC or heat pump, including:

• Protect your investment: Ductless mini split air conditioners and heat pumps are not cheap, and you will need additional materials such as refrigerant piping, approved wiring, refrigerant and specialized tools. You can protect your investment by also paying for professional installation.
• Easy and painless process: Most DIYers know that even the simplest projects can result in unexpected circumstances that can make the job longer, more complicated and difficult than planned. A professional installer can often foresee issues and will likely be better equipped to handle issues that come up.
• Avoid the risk damaging your system: Amateur installers don’t have the training or experience to ensure proper installation. Common mistakes include improperly sizing the system, overcharging or undercharging the system, making the refrigerant lines too long, and not allowing enough clearance around the units.
• Risk of electric shock: Ductless installation involves running electrical wiring, including making connections with the electric service panel, installing a disconnect box and more. These tasks require great care and if not done properly.

For these reasons and more, we always recommend getting a quote from a professional. To find a Carrier expert in your area, check out our dealer locator on our residential products website.

Ductless Air Conditioner Installation FAQs

Even when hiring a professional, many people have questions about ductless air conditioner installation which may impact their decision-making when deciding whether ductless is the right answer. Here are some common questions:

How Far Can a Mini Split Be From the Condenser?

The distance between the indoor unit and the outdoor unit in a mini split air conditioner or heat pump system can vary, based upon the manufacturer’s specifications. For flexibility of placement and other reasons, some manufacturers like Carrier offer units that allow longer lineset lengths of up to 328 feet. Most average installations are likely shorter.

What Kind of Wire Do I Need for a Mini Split?

Many ductless mini split systems require 14 AWG, 4 conductor stranded cable that not only delivers power to the system, but carries information between the indoor and outdoor units as well. The cable will often need to run through conduit per local code.

What Size Breaker Do I Need for a Mini Split?

Smaller units may only require 110 volts, but many ductless mini split systems require 220 or higher voltage on its own breaker.

How much clearance do I need for a mini split outdoor unit?

Manufacturer’s recommendations vary, but your outdoor unit will need clearance for air to flow through the unit’s condenser coil and out of the unit to allow for the heat transfer needed for heating or cooling operation.