5 Air Filter Efficiency Factors To Help You Choose A Better Filter
When it comes to indoor air quality, and especially the presence of allergy-causing or disease-carrying particles in the air, your first and best line of defense is a good HVAC air filter. Not all air filters are equal, though; there can be vast differences in air filter efficiency between different models. To determine which filter will do the best air-cleaning job for your Georgia home, there are five air filter efficiency factors to consider:
Efficiency. The overall air filter efficiency rating refers to the percentage of small particles that the filter will remove from the air passing through it. For example, a 50 percent efficiency filter would let half the airborne particles pass through, while a 99 percent efficiency filter would only let 1 percent of those same particles through. Generally speaking, higher efficiency also means the filter will capture smaller particles; if the smallest particles cannot pass through, larger particles will obviously also be blocked.
Initial efficiency. This is simply the efficiency rating when the filter is brand new. In most cases, a filter is less efficient when new; capturing dust particles helps “plug the holes” and make the filter more efficient over time.
Sustained efficiency. This is the efficiency level that the filter can maintain throughout its life.
Pressure drop. Pressure drop is the amount that the air pressure drops when passing through a filter. It tells you how much the filter impedes airflow. Higher air filter efficiency often results in a higher pressure drop. This is not a good thing; it means your blower has to work harder (and use more electricity) to move the air. High pressure drops can be managed through proper duct design.
Dust holding capacity. This is the amount of dust (or other particles) that the filter can hold. A filter with a higher dust-holding capacity can last longer before replacement.
Our goal is to help educate our customers in Peachtree, GAand surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about air filters and other HVAC topics, download our free Home Comfort Resource guide.