If your sytem is still cooling, but is noticabally less effecient, your problem could be a few different things. You could possibly have a dirty air filter. A dirty air filter will restrict airflow through your system, reducing effeciency and the systems ability to condition air. Another common issue is that your system could be low on freon. An air conditioning system uses pressurized freon to heat and cool, so a reduction in pressure will reduce its ability to condition indoor air. You could have a problem with an expansion device, or there could be a major duct leak or restriction in your duct system though this is less likely. The age of your system also plays a role in how well it cools. As they age, they do become less efficient. The best thing to do is have regular maintenance performed on your system. This will likely give you some answers for the ineffeciency.
- Dirty Air Filter: A dirty air filter cause limit air flow through the system and cause it to run inefficiently. Make sure to change out your air filters at least every 2 months. For more info
- Low on Freon: An air conditioning system uses pressurized freon to heat and cool, so a reduction in pressure will reduce its ability to condition indoor air.
- Refrigerant Flow : Refrigerant flow problems will be diagnosed by a service technician. These problems are freon pressure related. Some examples are restrictions in expansion devices, trash or debris in freon line sets, or kinked freon lines.
- Duct Issue or Leak : Duct work can develop tears or collapses as it ages, this should be taken into consideration when diagnosing effeciency problems in your system. A simple collapse of a return air duct can produce symptoms which can be confused with freon problems. To increase effeciency, older ductwork should be inspected for significant leaks and repaired properly.
- Efficiency of system : Air conditioning systems will lose effeciency as they age. Proper maintenance can help prevent this through proper cleaning of the equipment and replacement of bad parts.