3 ms·
My point was that 4x 1" filters assembled into a box is the same surface area as 1x 4" filter, but the latter is much easier to assemble.
by DeRock 3y ago
My point was that 4x 1" filters assembled into a box is the same surface area as 1x 4" filter, but the latter is much easier to assemble.
- oh_sigh 3y agoAgreed, but it might cause your fan to burn out much quicker, or be less productive if you're using a box fan, since the static pressure differential will be approximately 16x between the two.
- sgc 3y agoWhy? 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]
- sfink 3y ago??? 4 x 1" filters, each with a surface area of 10 square megamicrons, provide a total of 40 square megamicrons when assembled into a box. A single 1 x 4" filter strapped to a fan gives a total of 10 square megamicrons. How are those the same surface area? Ah! I get it, because of the pleating. I guess it depends on whether the greater incoming airflow interferes with itself once it gets squeezed between pleats.