When it comes to air filters, the general consensus is that a thicker filter will restrict airflow. But is this really true? The answer is not as straightforward as it may seem. A thicker filter, such as one that is 4-5 inches thick, does have more surface area and therefore leaves more room for air to pass through. However, a 1-inch filter with less surface space will clog up quickly and need to be replaced more often than a coarser filter.
Additionally, the combination of a thin air filter with a high MERV rate can also restrict airflow to the point that it hinders efficiency and causes excessive wear and tear. In general, a filter with a higher MERV rating will reduce airflow. This is because the higher the filter rating, the smaller the particles it will capture and the higher the percentage of particles captured. Low-efficiency filters are generally within MERV 1-4 and high-efficiency filters are MERV 13 and later.
The MERV scale is not linear; the difference between a MERV 6 and a MERV 8 is almost double in the percentage of particles captured. It is important to note that as the MERV rating increases, the filter becomes more restrictive and more pressure and energy will be needed to propel the air. This means that pleated air filters do restrict airflow to your HVAC system, but all air filters will restrict airflow to some extent. The key is finding the right filter for your unit and your overall system to ensure that you reduce the amount of contaminants in the air as much as possible while also providing enough airflow for your HVAC system to operate efficiently.
This means that you should look for an air filter with a higher MERV rating that is also less restrictive to airflow. If you use a fine filter that restricts airflow too much, your air conditioner can turn off or your system may not be able to provide enough heating or cooling to your home. Additionally, using an air filter with too low of an efficiency rating can cause your HVAC system to work harder than necessary. Pleated filters have innovated the way fibers are woven, as well as what they are made of, to increase filtering capacity and decrease fabric density.
This means that they are less restrictive to airflow, which helps the HVAC system operate more efficiently. A 1-inch air filter may need to be changed every month, while a 4-inch air filter can last up to six months. 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. Additionally, some technicians anticipate that people will forget to change their filters, and regular use of low-efficiency filters could help minimize damage to a neglected HVAC. Deeper pleated filters allow dirt to spread over a larger surface area, reducing pressure drop and allowing filter changes less frequently without significantly affecting system performance. In conclusion, while thicker filters do restrict airflow, they also provide better filtration and longer lasting performance than thinner filters.
It is important to find an air filter that meets both your air filtration needs and airflow requirements in order for your HVAC system to operate efficiently.