DIY: Central Air

Installing your own central air conditioning can save you some money--and rescue you and your family from another sweaty summer. You can do it if you are handy, but there are several things to take care of before you start.

Before You Begin

Before you begin, you should hire an air conditioning contractor to come and help you finish. While you will be able to do about 90 percent of this project yourself, you will need the help of a contractor before you are through. The contractor should only have to be there for an hour or two, which will keep the cost low. The contractor will inspect all the work you have done to make sure it was done correctly, solder copper refrigerant lines, connect the wiring to the house (this is high-voltage wire and should only be looked at by professionals), start up the machine, and help you dispose of any old freon you may have if you are replacing an old air conditioning unit.

Unit Placement

The first major task in installing the air conditioning is placement of the unit. The unit should be outside, next to your home. Try to place it somewhere out of the way, but still easily accessible should any repair work be needed. The unit should sit 10 to 13 inches away from the house. If you have shrubbery, clear away any branches which might get in the way of the unit. Also, make sure that the ground you are placing the unit on is completely flat.


As you begin to install your air conditioning, safety must always be the most important thing on your mind. You’ll begin by cutting a hole in the side of your house with a hole saw. Make sure this is away from any pipes or electrical conduits.

Once you begin the interior installation, you will need to cut into sheet metal to install your coils into the supply plenum. Even though you will be letting the contractor hook up the final copper piping to the coils, you will be installing the coils to the main unit and running them from the unit to the area where the coils are. Make sure these are out of the way and firmly fastened to the beams and studs which make up your house.

Finally, you will need to hook up the low-voltage wiring that runs from the unit to the main air handler. Make sure that the power is off, as you do not want to risk electrocuting yourself.