What does the term "Pressure Drop" refer to in air filter performance?

The term "Pressure Drop" in air filter performance specifically refers to the resistance to airflow through the filter. When air passes through a filter, it encounters resistance due to the filter media and any particles that may have been captured by the filter. This resistance results in a measurable difference in air pressure between the upstream and downstream sides of the filter, which is essential for evaluating how effectively the filter can maintain airflow in a system.

Understanding pressure drop is crucial for filter selection and system design. A higher pressure drop generally indicates that the filter is either more restrictive or that it has accumulated more particulates, which can affect overall system efficiency and performance. It's important to monitor pressure drop to ensure that air filters are functioning correctly and to prevent excessive strain on fans and blowers in HVAC systems.