Keeping Your Air Conditioner in Tip-Top Shape

Maintaining your air conditioning (AC) system is an important part of keeping your home comfortable and energy efficient. One of the most critical components of regular AC maintenance is replacing the filter. This filter traps dust, dirt, and other particles from circulating through the air in your home. If it gets clogged or dirty, it can reduce the efficiency of your AC and cause other problems.

The frequency with which you should replace your AC filter depends on several factors, including the type of filter you have, where you live, and how often you use your AC. Generally speaking, it's recommended that you change out your AC filter every one to three months.

Different Types of Filters

There are a variety of different types of air filters available on the market today. The most common ones include fiberglass filters, pleated paper filters, washable electrostatic filters, and high-efficiency particulate air (HEPA) filters. Each type has its own advantages and disadvantages.

Fiberglass Filters

Fiberglass filters are made from spun glass fibers woven together in a mesh pattern. They're inexpensive and easy to find, but they don't offer much filtration power, so they should be changed out every month.

Pleated Paper Filters

Pleated paper filters are more effective than fiberglass because they have more surface area for trapping particles. They're made from layers of pleated paper that can capture particles as small as 1 micron in size, so they should be replaced every two to three months.

Washable Electrostatic Filters

Washable electrostatic filters are constructed from a mesh of metal fibers that create an electrostatic charge when air passes through them. This charge attracts and traps particles, making them more effective than fiberglass or pleated paper. These can last up to six months before needing to be washed or replaced.

HEPA Filters

HEPA (High Efficiency Particulate Air) filters are considered to be the most effective type available. They're made from a special material that can trap particles as small as 0.3 microns in size, so these should be switched out every three to six months depending on where you live.

Factors That Affect Filter Replacement Frequency

In addition to what kind of filter you have, there are several other factors that influence how often you need to replace it:

  • Environment:
    If there's high levels of dust or pollen where you live, then changing out your filter more frequently may be necessary.
  • Usage:
    If you use your AC system frequently, then changing out the filter more often will help keep it running efficiently.
  • Pets:
    If there's pets living with you at home, their fur and dander can quickly clog up a filter if not changed regularly enough.


Replacing an old or dirty air conditioner filter is essential for keeping your system running smoothly while also improving energy efficiency. The frequency with which this needs done depends on several factors such as what type of filter is being used, environment conditions, usage rate, etcetera.

In general though, it's recommended that all types get replaced once every one to three months for optimal performance.