How often does the air filter for my heating and air conditioning system need to be changed?

Are the return air vents in your house covered with dirt?  If so, you’re not cleaning or replacing your filter often enough!Here’s a question we get asked on a regular basis; how often should I replace the air filters and my furnace?

You should replace or clean the filter once a month.  With forced air furnace systems, air recycling from the interior of the home to the furnace blower first passes through the air filter which is designed to catch a dust and debris and help clean the air before it cycles through the home again.  When filters become dirty or clogged, it only cuts down on the efficiency of the furnace, but over time it can cause parts to wear out faster.

Remember to turn the power off to the unit before you change the filter and check your owner’s manual for the recommended filter type.

A disposable furnace filter is made of a fiber mesh in a cardboard frame.  You can find the size of the filter printed on the edge of the frame.  There are special filters available that will do a much better job than the average disposable type.  The pleated panel filters usually cost around $5 for the average heating system and are much better at removing dust particles.

Most package filters have an arrow stamped on them to indicate the direction of air travel through the filter.  An arrow on the edge of the frame indicates the correct direction of airflow through the filter.  Air flows from the return air duct toward the blower, so the arrow on the filter should point toward the blower and away from the return air duct.

Washable filters should be washed and treated every month.