Why should I change my filter?

When is my filter too dirty?

What does a dirty filter do to my system and my electric bill?

To answer these questions above, one you first need to know what is the purpose of a filter.  The filter in a system filters the dirt out of the air flow.  That air flows through the coil and out the duct work into the house.  When a filter gets dirty, it restricts the air flow causing problems such as the freezing up of your system.  more importantly it an cause your system not to cool.  The dirtier your system is the more it runs which causes your electric bill to be high.  The key is to change your filter every month.  A great reminder is to change it everytime you get your electric bill.  

How do I know my filter is dirty?

If you can hold your filter up to the light and see light it is long overdue.  It can cause small problems like causing a compassitor to go bad to larger problems like causing a compressor to go out.  All these problems can be avoided by changing your filter everytime you get your electric bill.  If you just cannot keep your filter changed, get a preventative maintenance agreement which is where an air condition service technician comes to your house twice a year (once before the summer and once before the winter) and does a 50 point check to make sure that everything works properly.