How Often Should You Change Your Furnace Filter Or Air Conditioner Filter?

When people begin talking about furnace filters and air conditioner filters there are two commonly asked questions. What type of furnace filter should I use and how often should I change my furnace filter.

There are really no easy answers to these questions because there are so many variables to consider. What type of filter do you use? Is the filter for air conditioning or heating? Where do you live? Do you have allergies? Are you trying to control dust?

What Type Of Furnace Filter Do You Use?

If you use a furnace filter that is very inefficient such as fiberglass disposable filters, you can get away with only changing these filters at the beginning of each heating season. I have done this myself. These filters are very inefficient and it takes a long time for the filter to become plugged with dust. However these filters are so inefficient that I don’t recommend using them.

Is The Filter For Heating Or Air Conditioning?

This is an important question because an inefficient filter in an air conditioning system will allow dust to collect on the evaporator which will eventually need to be cleaned. This is best avoided because nobody wants to call a service guy if it can be avoided.

For this reason it is best to choose a more efficient filter for your air conditioner. Some suitable choices for an air conditioner filter would be pleated filters, electrostatic filters and media air filters. The more efficient your air filter is then the more often it will have to be cleaned or replaced. If not properly maintained they can cause restrictions to air flow and lead to operating problems.

Where Do You Live?

If you live in an area where there is a lot of construction or where the roads are not paved then you should change your furnace filter at least every two months. If you live in a relatively dust free area then every three or four months should be sufficient.

Do You Have Allergies?

If you have allergies then you should be using a relatively efficient furnace filter. A pleated filter with a high MERV rating or an electrostatic filter. HEPA filters are the most efficient but can cause too much restriction to air flow which leads to other problems.

Are You Trying To Control Dust?

If dust control is high on your list then you will want to use one of the more efficient furnace filters or air conditioner filters. As mentioned earlier, the more efficient the filter is then the more often it will have to be changed or cleaned.

Furnace filters and air conditioner filters should be changed every one to four months depending on your individual situation. The more efficient the furnace filter is then the more often it should be changed. Once you have been doing your filter changes or maintenance for some time you will begin to know how often it is necessary to change it. Follow manufacturers recommendations and you shouldn’t have any problems.