Select Replacement Filter — Identify Filter Size and Type
Part of project
AC Filter Replacement · Step 4 of 8
In this video
When choosing a new air filter, you'll encounter various types with different filtration ratings, such as MERV (Minimum Efficiency Reporting Value) or FPR (Filter Performance Rating). Higher numbers on these ratings indicate greater filtration capability, capturing smaller particles like allergens, mold spores, and even some bacteria. However, a higher rating also means the filter is denser, which can restrict airflow. Most HVAC technicians recommend using a filter in the middle to low-end range (e.g., FPR 4-7 or MERV 7-10) for optimal balance between air quality and system efficiency. If someone in your home has severe allergies, a higher-rated filter might be beneficial, but be aware that it might require more frequent changes and could potentially strain your blower motor if your system isn't designed for it. Ensure the new filter's dimensions (e.g., 16x25x1 inches) perfectly match the old filter's size; a filter that is too small will allow unfiltered air to bypass it. Writing the filter size on the plenum is also a useful tip.
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.
Select Replacement Filter — Identify Filter Size and Type
Part of project
AC Filter Replacement · Step 4 of 8
In this video
When choosing a new air filter, you'll encounter various types with different filtration ratings, such as MERV (Minimum Efficiency Reporting Value) or FPR (Filter Performance Rating). Higher numbers on these ratings indicate greater filtration capability, capturing smaller particles like allergens, mold spores, and even some bacteria. However, a higher rating also means the filter is denser, which can restrict airflow. Most HVAC technicians recommend using a filter in the middle to low-end range (e.g., FPR 4-7 or MERV 7-10) for optimal balance between air quality and system efficiency. If someone in your home has severe allergies, a higher-rated filter might be beneficial, but be aware that it might require more frequent changes and could potentially strain your blower motor if your system isn't designed for it. Ensure the new filter's dimensions (e.g., 16x25x1 inches) perfectly match the old filter's size; a filter that is too small will allow unfiltered air to bypass it. Writing the filter size on the plenum is also a useful tip.
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.