4 ms·
Why? If they have the same surface area, I would think they would have the same pressure differential?
by sgc 3y ago
Why? If they have the same surface area, I would think they would have the same pressure differential?
- oh_sigh 3y agoImagine calculating all possible routes an air molecule could take to escape after it is blown in. In the box case, the air molecule has 4 potential escape routes instead of 1 in the direct stacked filter case. And each escape route has it traversing 1/4 the amount of filter material.
- sgc 3y agoRespectfully, I think you don't understand how air filters work. Air does not pass through 4x the filter material in a 4 inch filter. Instead, the 4 inch filter is pleated, folded like an accordion, so that each air molecule passes through the exact same thickness of filter as a 1 inch filter of the same MERV rating, but ~3x more surface area allows for ~3x more air to pass through. This is the only reason for making a thicker filter - to allow greater air flow. A box fan is generally operating below the capacity of the 4 inch filter, which is designed to allow for high cfm whole-house airflow.
- deleted 3y ago[deleted]