Filter Cleaning

Change Your Air Filters Regularly

The US Department of Energy’s Energy Star program recommends that you “change your filter every month, especially during heavy use months (winter and summer).   If the filter looks dirty after a month, change it.  At a minimum, change the filter every 3 months.”

Changing filters is a relatively easy job but in reality filters are seldom, if ever, changed.  Reasons for not changing filters are plentiful:

• Don’t think about it
• Only think about it when dealing with an HVAC problem
• Difficult to access
• The system seems to be functioning okay — leave well enough alone
• Changed it in the past and it didn’t seem that dirty

Why It Is Important

When a filter is dirty, a number of bad things happen.  They are almost imperceptible because they happen slowly over time.

1. Air has a difficult time moving through the filter.  This decreases the available air to the fan and makes it work less efficiently.
2. Excessively dirty filters reduce the pressure provided by the blower fan.  This causes the system to run longer in an effort to provide the same amount of heating and cooling.
3. Eventually system maintenance will be required in order to return the system to its original level of performance.

Serious Maintenance and Efficiency Issues

Often, there is enough space around filters to allow some unfiltered air to pass.  The amount of airflow through this space will increase as passage through the filter becomes more difficult.  As the filter becomes dirtier, it will reach a point where not enough air will be able to bypass the filter and the filter will either distort or completely cave in allowing all the air to pass.  Once this happens, the dirt in the air WILL accumulate on the fan, reducing the fan capacity.  Dirt will also accumulate on the cooling coil, further reducing the airflow throughout the year and reducing cooling capacity and efficiency when the air conditioner is used. 

• To correct these problems the fan and cooling coil MUST be professionally cleaned
• If not corrected, unfiltered air can lead to total system failure
• Occupant may not know these things are happening until the system fails

Prevention is Key

• Consider purchasing filters in bulk so you have them on-hand
• Record the filter size on a sticker and affix it in a prominent place on the heating/air conditioning unit (also place a card in your wallet or purse)
• Incorporate a filter-check into your monthly routine along with another task such as paying bills
• If your filter is in a location you frequent, you may benefit by installing an inexpensive filter whistle designed to sound when the filter is dirty.  Various whistles can be purchased at home improvement stores or via the internet for $3-$20.

Changing or cleaning your furnace filter regularly is one of the simplest ways to keep your heating and cooling system happy, providing you and your family with comfort and efficiency year-round.