DIY Mini Split Ductless AC Installation

mini split ac

High temperatures mean uncomfortable conditions in your home this summer. Installing a mini split air conditioning system can provide cool relief and you can install it yourself for under $2000.

Why spend $10,000 or more on central air conditioning systems when you can save on installation costs and time installing a mini split system yourself.

The mini split ac system today come pre-charged with refrigerants and step by step instructions for do it yourself installations. Our guide will walk you through preparation, design and installation of a mini split residential install.

Preparation planning and design

The most important part of this install is picking the right size AC. Too small and the unit will run constantly, waste energy and create a stuffy environment. The rule is 20 BTU per square foot of space so a 250 sq ft space would require 5000 BTUs to properly cool the space.

To measure square footage use a tape measurer and measure the width and length of the space then multiply the two. For odd shaped spaces you can break then up into sections to measure.

Determine which rooms you want the wall mounted units placed in to determine the size of the system then refer to the manufactures chart to order you mini split system. Also contact you local codes office for any restrictions that may apply. In some cases more then one system will need to be purchased.

Tools

Drill
Drill Bits
Set Screwdrivers
Level
Tape Measurer
Multi-Meter
Thread Tape
Wire Cutters
Adjustable Wrench
Ladder
Gloves
Eye Protection

Locating the mini split AC interior units

Indoor wall units should be place high on the wall away from anything that can block the flow of air including furniture and curtains.

They should be mounted close to electrical outlets for power and near drainage areas. The outdoor unit should be placed on flat stable ground in a shaded area if possible for better cooling.

12 inches minimum is required between walls and the outside unit. It helps to map out your placements on paper.

Installing the Indoor ductless unit

First locate and mark the wall studs using a wall stud finder. If no studs use heavy metal anchors.

Mark the bracket using a level following the instructions that came with the unit. Double check to make sure the unit is level.

Setting Up the Condensate Drain Line

The indoor wall unit will produce condensation water that must be drained. A hose and mounting hardware are provided .

There are two mounting methods. Drill through the wall for an exterior evacuation of water or use brackets to secure the hose to the interior wall. In any case this hose must be kept clear to avoid backup of condensation water.

Mounting the outside condenser unit

The outside condenser needs to be mounted on a solid surface. Platforms can be purchased or you can pour a small concrete slap to mount the condenser on.

A condenser can also be wall mounted to the exterior if needed. Rubber pads should be place under the unit to absorb heavy vibrations. Double check level and that the install is solid.

Connecting service lines from interior units to exterior condenser and testing

Connecting the two units from inside to the outside requires drilling a hole through the wall. Following the instructions from your specific model then feed all the lines to the outside and secure.

Be sure to seal the hole properly to keep rain and bugs out. At this point you have to decide to connect the Refrigerant Lines, drain and power yourself or hire a professional to connect the system and test.

Most states require only licensed professionals to test air conditioner refrigerants. Having said that you can hookup electrical, controls and run the system.

Before hooking up power turn the circuit off at the breaker panel. Strictly follow the instructions that came with your mini split AC for hooking up refrigerant lines, drains, power supply and controls.