Do Filters Reduce CFM? An Expert's Guide to Finding the Right Balance

When it comes to air filters, it's essential to understand how they affect the airflow of your HVAC system. Each filter size provides different resistance to each size and style of fan placed in it, and a filter with the maximum exhaust CFM rating has approximately 0.7 wg. All fans will have a lower CFM at a higher pressure, and in general, dust filters reduce airflow. Depending on the type of filter, it can be as low as half the airflow that fans are made for.

It's important to note that some people use static pressure fans when they have filters, but in general, a filter with a higher MERV rating will reduce airflow. However, there are many other factors at play, such as the size of the filter and the type of fan motor in your HVAC system. This usually coincides with a higher MERV rating; however, this also means that the filter is a bit more restrictive and that the air flow through it is lower. When looking for air filters, air filters with more pleats will allow for greater airflow, all things being equal. While it is true that the more the air filter traps, the more effective it will be at capturing more particles, it will end up becoming too charged, at which point the air flow could be zero and extremely restrictive.

The denser the fabric or the thickness of the filter material, the more particles and contaminants the filter can trap. The higher the MERV rating, the more efficient the filter is at filtering and capturing particles and contaminants from the air. The amount of HVAC airflow slowed by the filter is equivalent to the filter pressure drop. You don't want to buy an industrial pleated filter and install it in your home, as that will cause the system to overcharge and eventually break down. If you're trying to choose the right air filter, you might be wondering if pleated air filters restrict airflow to your air conditioning system.

All filters restrict airflow to a certain extent because, in all cases, air has to pass through the filter so that the unit can remove particles from the atmosphere. However, we use a pleated accordion-like material which allows us to effectively increase the filter surface without causing a large drop in pressure or restricting air flow. The pressure drop of an air filter is the measure of resistance to air passing through the filter. For example, a household pleated filter using synthetic media will have a lower pressure drop than a glass microfiber filter used in critical environments such as hospitals and data centers. Many people don't realize how a filter with a high MERV rating will affect other parts of their HVAC system. A higher MERV rating means that more particles are being trapped by your air filter; however, this also means that there is less airflow passing through your system.

This can lead to an increase in energy costs as your HVAC system has to work harder to maintain its temperature settings. When selecting an air filter for your home or business, it's important to consider both its efficiency and its effect on airflow. A higher MERV rating may mean better filtration but could also mean reduced airflow and increased energy costs. Finding a balance between efficiency and cost-effectiveness is key when selecting an air filter.