Yes. Dirty or incompatible filters can restrict airflow. MERV measures particle capture; resistance also depends on filter design, size, loading and airflow. See PNNL’s filter guidance. If replacement changed the steady flow of air, check the approved specifications.
Dirty Air Filters
A loaded filter adds resistance. Depending on the blower and controls, airflow may fall or electricity use may rise. Excessive restriction can damage equipment. Replacing filters does not guarantee a particular saving or equipment lifespan.
MERV Measures Capture, Not Compatibility
MERV compares particle capture at specified sizes. EPA recommends MERV 13, or the highest rating your fan and filter slot can accommodate. Consult an HVAC technician if compatibility is unclear. Equipment age alone does not determine the appropriate filter.
A lower MERV number does not establish a filter’s loading rate or compatibility. Start with the equipment specifications and exact filter model.
Follow the manufacturer’s inspection, cleaning and replacement instructions. There is no universal monthly replacement requirement for every low-MERV filter. Record the installation date and replace a disposable filter, or clean a reusable one, as directed.
HEPA Is a Separate Filter Designation
HEPA performance is a separate designation, not simply “MERV 17–20.” EPA’s comparison explicitly separates HEPA from the MERV rating system. Do not assume a HEPA filter fits your central system; verify compatibility before making that change.
The Goal: Filtered Air That Flows Freely
A linked airflow demonstration cannot measure your system. Ask a technician to compare filter pressure drop and system airflow with equipment specifications. Higher MERV does not automatically mean greater resistance; filter surface area and design also matter.
Turn equipment off as its manual directs before opening filter access. Check dimensions, seating and airflow-arrow direction. Record new noises and affected rooms. Get qualified service for malfunctions or an unclear replacement specification. Do not bypass safety controls, alter blower settings or operate without the required filter.
