Do Air Filters Restrict Airflow?

If you have a dirty air filter, it can cause low airflow and make your HVAC system work harder, reducing efficiency.


, pleated air filters do restrict airflow to your HVAC system, but all air filters will restrict airflow to some extent. You should find the right filter for your unit and overall system to reduce the amount of contaminants in the air as much as possible. High MERV pleated filters capture a lot of contaminants, but they also restrict air movement to the blower or oven, making the fan work harder.

Electrostatically charged filters work well for a week or two, as they have a negative charge that attracts and retains negatively charged particles. However, once the surface is “covered” by particles, the electrostatic benefit disappears. Electric air purifiers also restrict airflow. Your air conditioner can turn off if fine filters restrict airflow, and it will be stressed by a dirty filter that slows down airflow, causing the system to work harder.

This can result in not enough heating or cooling being provided to the home, or just one or two distant rooms becoming uncomfortable. Many air conditioning manufacturers recommend using an air cleaner with a MERV rating of 8-9 to balance air allergen filtering with the cost and stress of the HVAC system. Low-MERV filters (think MERV 1) filter relatively few particles compared to high-MERV filters (think 11-1). When your filters are clogged, particles escape through the filter and enter the mechanical and electrical components of the AC system.

What Are The Different Types Of Air Filters?

Pleated air filters have innovated the way fibers are woven, as well as what they are made of, to increase filtering capacity and decrease fabric density. MERV values typically range from 4 to 14, and the filter package tells you what type of contaminants the filter is capable of capturing. HEPA filters are usually installed as part of a system with an included fan, as the blower or oven fan will not be able to move enough air through the filter without assistance. Electrostatic air filters have layers and layers of filtration that clean the air as it passes through the filter.

Don't fall for the “hype” of sorting systems, cleanable filters, or electrostatically charged filters.

How Often Should You Change Your Air Filter?

One-inch pleated filters should be changed at least every three months, and pleated filters four or more inches should be changed approximately every six months. This is because any oven filter that removes contaminants and dust from the atmosphere within its property will continuously filter the air, resulting in a shorter lifespan if not changed in time - not by using a cheaper filter.