Skip to Content

Why the End of Summer Calls for Changing Your Air Filters

Air Filters

Remembering to change your air filters in your HVAC system should be on your seasonal to-do list. Your air conditioner and furnace share a common filter installed in the ductwork.

Donandrsquo;t go into the heating season with a dirty, clogged air filter left over from the summerandrsquo;s heavy cooling season. System airflow is one of the most critical system specs when it comes to ensuring maximum energy efficiency and optimum performance. The condition of the filter is a major factor that impacts proper airflow.


If you don't know how to change your air filters, any HVAC contractor will be happy to show you. Once itandrsquo;s done, observe proper intervals for filter changes thereafter during the winter. The typical A/C runs more hours per average day during summer than the furnace runs during winter. Most experts, therefore, recommend monthly filter changes during summer. In our winter climate, however, the lower daily hours of furnace operation permits longer filter replacement intervals. Ideally, you should visually inspect the filter every month during heating season. If it appears conspicuously dusty or dirty, install a fresh filter immediately. If not, simply replace the furnace filter every other month.


Observing proper filter change intervals is just one issue relating to airflow and air quality. The type of filter installed is also important. Cheap fiberglass panel filters (often considered “throwawaysandrdquo; by HVAC technicians) provide poor filtration efficiency and remove little more than the largest visible particles of inorganic dust. Their main function is to protect moving parts in the system from dust contaminationandmdash;not protect your healthy indoor air quality. Instead, choose quality pleated polyester or cotton filters for better filtration performance. A pleated filter with a MERV (minimum efficiency reporting value) around 8 provides the best balance between filtration efficiency that removes airborne particulates down to as small as 3.0 microns while still enabling optimum airflow through the ducts.

For more about when to change your air filters, contact the professionals at Valley Heating, Cooling, Electrical.

Our goal is to help educate our customers in the South Bay Peninsula and Santa Cruz areas of California about energy and home comfort issues (specific to HVAC systems).

Share To: