The coolant used in most air conditioning systems is a refrigerant called Freon. If the system does not contain the proper amount of Freon, little or no cooling will take place. If you suspect a Freon problem, call a professional service person to recharge the system. Caution: Do not try to charge your system's refrigerant lines.
Here's how you can repair the system's coolant lines. Examine the lines running from the condenser outside the evaporator inside the house. If the insulation is damaged or worn, it will cut down on the cooling efficiency of the unit and, therefore, should be replaced.
Replace damaged or worn coolant line insulation with new insulation of the same type as soon as possible. Follow manufacturer's instructions for installation.
Many homes or apartments use window-unit air conditioners, so it's also important to know how to maintain or service these smaller units. Learn how to head off problems and keep these units running smoothly in the next section.