Locate Filter and Identify Airflow — Locate the HVAC Air Filter
Part of project
AC Filter Replacement · Step 1 of 8
In this video
Once the power is off, locate the air filter within your HVAC system. It is typically found in the return plenum (the large metal duct) directly before the blower or main unit of the furnace. In some less common cases, the filter might be located behind an air return vent in a wall or ceiling. After locating the filter, carefully pull it out. Observe the 'airflow' arrow printed on the filter's cardboard frame; this arrow indicates the direction air should flow through the filter. For future reference and convenience, it's highly recommended to use a permanent marker, like a Sharpie, to draw an arrow on the return plenum itself, indicating the correct airflow direction towards the furnace.
FAQs
How do I find the correct size and type of replacement filter?
The filter size is usually printed on the cardboard frame of your old filter (e.g., 20x25x1). Note down these dimensions before buying a new one, like the ACDelco Air Filter A2014C. For filter type, MERV ratings (Minimum Efficiency Reporting Value) indicate how effectively a filter cleans the air; consult your HVAC system's manual or a professional to choose the appropriate MERV rating for your system.
Can I clean my old AC filter instead of replacing it?
Most residential AC filters, especially disposable pleated or fiberglass types, are not designed to be cleaned and reused. Attempting to clean them can damage the filter media, reducing their effectiveness and potentially pushing debris into your HVAC system. Always replace disposable filters with new ones to maintain air quality and system health.
What are common mistakes people make when replacing an AC filter?
A common mistake is installing the new filter backward; always ensure the airflow arrow on the filter points in the direction of the furnace or air handler. Another error is forcing the wrong size filter into the slot, which can lead to air bypassing the filter and reducing efficiency. Always double-check the dimensions and the airflow direction arrow before installation.
What if I can't find the filter slot on my furnace or air handler?
The filter slot is usually located where the return air duct enters the furnace or air handler, often in a dedicated slot near the main unit. It might also be behind a return air vent grille in your ceiling or wall. If you're having trouble locating it, consult your HVAC system's manual or look for a hinged door or cover near the main unit where the large air duct connects.
Locate Filter and Identify Airflow — Locate the HVAC Air Filter
Part of project
AC Filter Replacement · Step 1 of 8
In this video
Once the power is off, locate the air filter within your HVAC system. It is typically found in the return plenum (the large metal duct) directly before the blower or main unit of the furnace. In some less common cases, the filter might be located behind an air return vent in a wall or ceiling. After locating the filter, carefully pull it out. Observe the 'airflow' arrow printed on the filter's cardboard frame; this arrow indicates the direction air should flow through the filter. For future reference and convenience, it's highly recommended to use a permanent marker, like a Sharpie, to draw an arrow on the return plenum itself, indicating the correct airflow direction towards the furnace.
Frequently Asked Questions
How do I find the correct size and type of replacement filter?
The filter size is usually printed on the cardboard frame of your old filter (e.g., 20x25x1). Note down these dimensions before buying a new one, like the ACDelco Air Filter A2014C. For filter type, MERV ratings (Minimum Efficiency Reporting Value) indicate how effectively a filter cleans the air; consult your HVAC system's manual or a professional to choose the appropriate MERV rating for your system.
Can I clean my old AC filter instead of replacing it?
Most residential AC filters, especially disposable pleated or fiberglass types, are not designed to be cleaned and reused. Attempting to clean them can damage the filter media, reducing their effectiveness and potentially pushing debris into your HVAC system. Always replace disposable filters with new ones to maintain air quality and system health.
What are common mistakes people make when replacing an AC filter?
A common mistake is installing the new filter backward; always ensure the airflow arrow on the filter points in the direction of the furnace or air handler. Another error is forcing the wrong size filter into the slot, which can lead to air bypassing the filter and reducing efficiency. Always double-check the dimensions and the airflow direction arrow before installation.
What if I can't find the filter slot on my furnace or air handler?
The filter slot is usually located where the return air duct enters the furnace or air handler, often in a dedicated slot near the main unit. It might also be behind a return air vent grille in your ceiling or wall. If you're having trouble locating it, consult your HVAC system's manual or look for a hinged door or cover near the main unit where the large air duct connects.