How to Self Install a Central Air Conditioning

To cut costs, you can accomplish much of the installation of central air conditioning on your own, but you cannot complete the job unless you are EPA-certified to handle refrigerant.
Select a location for your condenser that is cool and hidden from sight.Select a location for your condenser that is cool and hidden from sight.
Is it relatively easy for the homeowner to set up the evaporator coil and condensing unit, and run the line sets between the two units. The remaining steps, including setting up wiring and running the refrigerant, should be left to a contractor. In any case, it is essential to adhere to manufacturer instructions, local building codes and electrical codes.

Step 1

Select an outdoor location for the condensing unit, ideally a shaded, level spot with at least 1 foot of clearance. Set down the condensing pad and place the condensor on top of it.

Step 2

Cut a small hole near the bottom of the wall next to the condenser, using a hole saw. This will allow wires to run to the electrical panel and pipes to run to the furnace/air handler.

Step 3

Install the evaporator coil inside the supply plenum located on your furnace or air handler. First, measure the evaporator coil and cut a slightly larger hole in the plenum with a drill and metal shears. If you are using an air handler, you can skip this step as the coil is already installed inside. If you have a cased coil, simply mount it on the furnace.

Step 4

Construct metal shelves inside the plenum for placing the evaporator coil. The back shelf should be ½-inch higher than the front shelf for water flow. Screw the shelves to the plenum and position flaps so they face downward.

Step 5

Place the coil on the shelves with the refrigerant lines facing outward. Cover with a sheet metal cover so the pre-cut holes line up with the refrigerant lines and drain connectors. Screw in place.

Step 6

Connect the line set to the condensing unit and run it along the ceiling to the evaporator coil. Secure it to the ceiling with mounting brackets. Remove some of the insulation to allow the line to fit through the hole

Step 7

Attach the suction line to the surface valve of the condensing unit. You may need to connect it to an angled copper tubing to direct it to the unit, as you do not want to create kinks in the line.

Step 8

Connect the liquid line to the condensing unit surface valves. Run it through the house onto the same ceiling brackets you installed and cut it with enough room to connect it to the evaporator.

Step 9

Install the thermostat and connect it to the condensing unit according to manufacturer instructions. Prepare the low-voltage lines between your circuit panel and the condensing unit if you are familiar with the process, but leave the remaining high-voltage wiring to your contractor to complete.

Things You Will Need

  • Condenser unit
  • Condenser pad
  • Hole saw
  • Evaporator coil
  • Tape measure
  • Drill
  • Metal shears
  • Metal screws
  • Sheet metal
  • Screwdriver
  • Ceiling brackets
  • Suction line
  • Tubing cutter
  • Liquid line


  • Contact a contractor to solder the lines to your unit, connect the refrigerant and complete the wiring installation.


  • Never attempt high-voltage wiring without advice and assistance from a certified electrician.
  • If any questions arise during installation, contact the manufacturer or a local air conditioning company for help.

About the Author

Carly Fiske has been writing professionally since 2009. She writes for websites including, and Fiske holds a Bachelor of Arts in cultural anthropology from the University of Redlands.