Your All-In-One Split AC Installation Checklist

Upgrading your comfort with a split AC is a cool move, but it requires more than just grabbing a ladder and hoping for the best. Our split AC installation checklist breaks down what can feel like a ginormous project into simplified steps. From stocking your toolbox to flipping the power switch, you'll know exactly what to prep for, what to pick up at the store, and what your pro will tackle on installation day, so you can finally chill.

Split AC Installation Supplies Checklist

Download Checklist Here

Let's face it, nothing kills your momentum like realizing you have to go to the hardware store mid-installation. Before starting your project, ensure you have the right tools on hand: 

• Drill and bits

• Level

• Stud finder

• Pipe cutter

• Vacuum pump

• Torque wrench 

• Electrical tape 

• Wire strippers

• Sealing foam or putty 

• Measuring tape

• Safety glasses and gloves

• Sturdy ladder

System Components Checklist

Each part of a split AC has a job. Understanding what they are and what they do is extremely important for DIY installations. If you’re not sure how it works, hire a pro instead. 

• Indoor air handler circulates cool air

• Outdoor condenser houses the compressor and coil

• Refrigerant lines move coolant between units

• Drain hose carries condensation outside

• Electrical cable links indoor and outdoor power

• Mounting plate secures unit to wall studs

• Line set cover protects tubing and wiring

• Remote or thermostat controls the temperature

Selecting a Split AC System Checklist

Ensure that the unit you buy is a good match for your needs and your abode:

• Compare single-zone vs. multi-zone systems based on room count

• Review energy efficiency ratings (SEER) to save long-term costs

• Match voltage requirements with your household power supply

• Check the included line length to see if you’ll need extensions

• Confirm warranty coverage for both parts and the compressor

• Review noise ratings for quiet operation in bedrooms or offices

• Verify heating capability if you want year-round comfort

Pre-Installation Planning Checklist

For those wondering how to install a mini-split system, the following will help you plan for a successful installation that works best for your home. 

• Measure room size to match BTU capacity with square footage

• Check the electrical panel to confirm it can handle the added load

• Plan drainage with a downward path for the condensate line

• Consider sun exposure—south-facing rooms heat faster

• Note ceiling height—tall spaces need extra cooling

• Evaluate insulation—drafty rooms need more cooling power

• Review furniture layout to keep airflow clear and unobstructed

Mounting Location Checklist

Where you place the indoor and outdoor units determines both performance and longevity. Use this list to plan the placement:

• Mount the indoor unit at least 6 feet above the floor

• Leave clearance of 6–12 inches on sides and top

• Avoid heat sources like ovens or direct sunlight

• Keep airflow clear of shelves, curtains, or furniture

• Choose the exterior wall for easier line routing

• Place the outdoor unit with 12 inches of side clearance

• Raise the condenser off the ground to prevent water damage

• Position the condenser away from the bedrooms for less noise

Installation Day Checklist

We don’t recommend DIYing this part. Here’s how the pros install a split AC unit:

• Attach the plate to the wall studs

• Drill hole with downward slope for lines

• Feed tubing, drain, and wires through the opening

• Connect copper lines with flare fittings

• Seal opening with foam or putty

• Mount the indoor unit and check the level

• Position the condenser on the pad or bracket

• Connect lines and insulate joints

• Wire connections per manufacturer diagram

• Vacuum lines to remove air and moisture

• Release refrigerant and check for leaks

• Power on and test the cooling cycle

How Much Does It Cost to Hire a Split AC Installation Pro?

Professional installation isn't cheap, but it spares homeowners a significant headache. Across the country, mini-split AC costs hover between $2,000 and $14,500. 

The wide range is determined by the number of zones you want to cool. A single room with one air handler falls at the lower end, while a multi-zone system with four or five units can quickly climb toward the top. The national average is around $3,000, covering a basic, single-zone system installed by a licensed contractor.

Factors that can raise your total include:

• Running new electrical circuits from your panel

• Building supports or concrete pads for outdoor units

• Handling tricky installations in attics or multi-story homes

DIY vs. Hiring a Pro

For a seasoned DIYer with solid contracting skills, undertaking the project yourself could save a substantial amount of money. Your main costs are the unit, tools, and supplies. However, there is a tradeoff: You'll spend a weekend sweating through the installation, and mistakes can be costly if refrigerant leaks or electrical issues arise.

Hiring a local HVAC specialist costs more up front, but it will boost your confidence knowing that the job's done right. They handle permits, properly vacuum the lines, and ensure safe wiring. Plus, most manufacturers require pro installation to maintain the warranty's validity. While DIY might save money on installation day, hiring a professional pays off in the long run with system lifespan and reliability.