If your energy bill is continually rising, then your AC unit may be to blame. You may have a unit that is losing its efficiency, which may be caused by a number of issues. If your unit is constantly running, then it may be losing its ability to cool your home. You may have low refrigerant in the line, your compressor may be malfunctioning, you may have a bad fan, or your evaporator coil may be frozen over — among other problems. Your energy bills may also be high if your home is poorly insulated, or if you have leaks throughout the ductwork of your house. You should also check the filter of your air conditioner to make sure that it is relatively clean, since a filter caked in dust and debris won’t be nearly as efficient as a new filter (learn more about filters below).