Do window AC filters need to be replaced?

Having a clean, well-maintained window air conditioner filter is important for proper airflow and cooling efficiency. But how often should you be replacing the filter? Here we’ll look at when and why you need to replace window AC filters.

How often should you replace window AC filters?

Most manufacturers recommend replacing window AC filters every 30-90 days during peak cooling season. More frequent replacement may be needed if:

• You live in a dusty environment
• You have pets in the home
• There are many people living in the home
• The AC unit runs very frequently

During off-peak seasons when the AC is not being used as heavily, you may be able to go longer between filter changes, closer to the 90 day recommendation.

Signs it’s time to change the filter

Don’t rely solely on a calendar schedule for knowing when to replace your filter. Look for these signs it’s time for a new filter:

• Decreased airflow from vents
• AC is not cooling properly
• Filter looks very dirty/clogged
• Unusual odors blowing from vents
• Increase in dust around vents/AC unit

Consequences of not replacing filters

If you use an AC filter past its recommended lifespan, it can lead to some problems:

• Decreased efficiency – dirty filters make your AC work harder to push air through.
• Higher energy bills – working harder uses more electricity.
• System damage – lack of airflow can damage AC components like the evaporator coil.
• Poor indoor air quality – dirty filters allow more contaminants to circulate.

What kind of filters do window ACs use?

The most common types of filters used in window AC units are:

Disposable polyester filters

• Made of woven polyester fibers
• Low cost purchase price
• Usually recommended to change monthly
• Not washable or reusable

Washable foam filters

• Made from polyurethane foam
• Can be washed and reused multiple times
• Need replacement after several wash cycles
• Provide basic air filtering

Pleated filters

• Made of pleated woven fabric
• Better filtration than foam or polyester
• May be washable and reusable
• Replace every 1-3 months for best performance

How to change a window AC filter

Replacing most window AC filters is a quick and easy process:

1. Turn off and unplug the AC unit.
2. Open the front panel. Filters are located behind the front grille.
3. Slide out the old filter. It may be in a plastic frame that slides out.
4. Check that the filter size matches and install the new filter in the same position.
5. Close the front panel securely.
6. Plug in and turn on the AC unit.

The process takes just a few minutes. Refer to your owner’s manual for model-specific instructions.

How to clean a reusable/washable filter

For foam or pleated filters that are cleanable, follow this process:

1. Remove filter from the AC unit.
2. Use a vacuum cleaner with a brush attachment to remove loose dirt.
3. Run filter under warm water. Don’t use hot water or detergents.
4. Rinse filter thoroughly until water runs clear.
5. Gently shake filter to remove excess water. Don’t twist or wring it.
6. Let filter air dry completely before reinstalling, usually 24-48 hours.

Avoid soaking the filter – this can damage the frame. Check manufacturer guidelines on cleaning recommendations.

Where to buy replacement filters

You can purchase replacement window AC filters from these sources:

• Local home improvement stores – carry universal and brand name filters
• Online retailers like Amazon – wide selection with filters for most models
• Direct from the manufacturer – best fit, often have subscriptions
• HVAC companies – can recommend and source the right size

Make sure to get the same size and style filter as the original. Have the AC model number handy when shopping for a new filter.

Conclusion

Replacing dirty, clogged window AC filters according to the manufacturer’s recommended schedule is important to keep your unit running efficiently. Air filters should be checked every 30-90 days during peak cooling season and changed if they appear dirty, have reduced airflow, or cause unusual odors from the vents. Disposable polyester and pleated filters are common, while foam filters can be washed and reused. Replacing the filter yourself is a simple and quick DIY task. Keeping up on fresh filters will save energy, prevent damage, and provide cleaner indoor air from your window AC unit.