Central air conditioning distributes air or cold water to several rooms in a building, providing for a more effective air conditioning than stand-alone air conditioner units. If it's getting hot and you don't have an air conditioner or only have a single unit, you might want to install a central air conditioning system. Although you will need help for parts of the work unless you have previous experience, you can do some of it yourself. This page is a guide on how to install central air conditioning.

Central air conditioning systems are more complex to install than single unit air conditioners such as window or wall mounted air conditioners. You will need the help of a professional for some of the work involved, unless you have experience with electrical installations. If you have not installed similar systems before, contact a professional for guidance, advice and planning before starting the work. This page takes you through the main steps of installing a central air conditioning system.

The first step to installing a central air conditioning is to understand how the system works.

1. Air conditioning systems consist of three main parts: an outside unit, which typically includes the condenser and compressor, an inside unit (air handler) where the evaporator is located, and ducts or pipes which distribute cold air or water to different rooms in a building.
2. Both the outside and inside unit will need to be connected to the main power supply of the home.
3. Sometimes the evaporator is located outside, eliminating the need for an inside unit.
4. If the air conditioning works by distributing cold air through several rooms, it will need ducts to do so.
5. If the air conditioning distributes cold water, which is turned into air in each separate room, it will require pipes.http://www.thisoldhouse.com/toh/article/0,,194722,00.html

Before installing the air conditioning, you will need to do some planning. Follow the steps below to make sure you do everything in the right order and don't spend extra time and money fixing mistakes.

1. You will need to make sure that the main power supply supports the system you plan to install. Consult an electrician for this. This is very important, as it can be dangerous to connect a system not supported by the main power.
2. If you do not have ducts to transport the cold air, (or pipes to transport cold water), you will need to plan for and install these first. This will take much longer than the installation of the air conditioning system itself.
3. You should also contact a professional to help you determine how big of a unit you will need to cool down the home, or the rooms which you want the system to service.
4. For more information on how to hire a contractor, visit Mahalo's pages on How to Hire a General Contractor, How to Hire a Plumbing Contractor and How to Find an Electrician.
5. The contractor should be certified or accredited in Heating, Ventilation and Air Conditioning.
6. Handing refrigerants require an appropriate certification, so seek assistance for this part. If you are replacing an old air conditioning system, you should also ask a contractor to remove the old system.

Next, it's time to start the installation of the air conditioning. Follow all instructions and safety guidelines for the components you are installing carefully. Consult local planning and building codes for requirements on installation, including the placement of components.

1. Start by installing the air handler unit. It is usually installed in a basement or attic. Follow the instructions that came with the unit.
2. Make sure turn off the main power to the house or building next! Continuing with the installation while having the power on can be very dangerous!
3. Install the compressor. It should be placed on top of a base. The space immediately surrounding the compressor should be empty, so don't install it right next to a wall, plants or other items. It should be placed on a stable and level surface.
4. Drill holes through the wall for the refrigeration and electricity tubes. Place filler between the wall and the tubes to prevent leakage.
5. Connect the compressor and air handler to the main power unit of the house.
6. Install the thermostat, if needed. Connect it to the air handler and main power supply.
7. Turn the power back on.
8. Check to make sure that the unit is working.

Installing a central air conditioning takes at least a few hours and will require some help from an electrician, unless you are one yourself. If you need pipes or ducts, it will take much longer. You might want to consult a contractor for additional help. If you are used to similar installations, you might be able to do the process yourself. Just make sure your main power supply supports the system before starting.