What generally determines the efficiency of a filter?

The efficiency of a filter is primarily determined by the particle size distribution of contaminants. This factor plays a crucial role because filters are designed to capture specific particle sizes depending on their intended application. When assessing how well a filter removes particles from the air, it is essential to consider the sizes of the contaminants; smaller particles can be more challenging to trap, while larger particles may not penetrate the filter media as easily.

The effectiveness of a filter in removing various particles directly correlates with the filter's ability to interact with those particles. Filters are often tested under specific standards that take into account the size and concentration of particles, which ultimately influences how well they perform in real-world conditions.

While other factors, such as the thickness of the filter material, can influence the overall performance and life of the filter, they do not directly determine efficiency in the same way that the particle size distribution does. The color of the filter media and the brand of the manufacturer are typically related to factors like marketing and aesthetics rather than performance metrics. Thus, understanding the particle size distribution of contaminants provides the most direct insight into a filter's efficiency.