You can also refer to your HVAC manual for exact filter locations and installation instructions if available.
How to Install an Air Filter in Your Home
the Right Way
Determining which way the airflow arrow points can be one of the biggest challenges when installing your air filter. A filter installed incorrectly can obstruct airflow, increase strain on HVAC equipment, and cost you extra.
The easiest method in determining which way the airflow arrow should point is to refer to the pre-existing filter before removing it and installing the new one in the same manner. If the old filter has already been removed or it is the first time you are installing a filter in the system, use these tips as a guide.
Position the airflow arrow so that it points in the direction the air is flowing.
In addition to clean air, filters also protect your HVAC system from debris and dirt buildup. The airflow arrow should point towards the furnace/blower motor to collect harmful particles before it reaches the furnace’s equipment.