DIYbanter - View Single Post - is it always better to use a thicker filter in furnace?

Smitty Two

In article ,
(Dave Martindale) wrote:

Smitty Two writes:

/\/\/\/\ -- that's a 1" thick pleated filter

I can't do it with my keyboard, but extend those pleats to 2" and
decrease the angle so each 2" pleat is just as wide as a 1" pleat, and
you've got twice the surface area.

Yeah, that part I get. Reducing the resistance is the part I don't.

The filter resistance per CFM per unit area remains the same, but you
now have twice the area of filter for the air to pass through. So the
CFM per unit area is reduced to half, and that reduces the pressure
drop.

A single 2" thick pleated filter is almost equivalent to two 1" thick
pleated filters in parallel (side by side, so half the air goes through
each).

Dave

I think your statements here are awkwardly worded, and I believe you
could do a little better. But maybe I just need to read it a few more
times. Given your pedigree on AHR, I'm going to mull these ideas over a
bit more and see whether I can follow your reasoning. So far, you're the
only one on the other side of the fence who's gone as far as to actually
present a credible argument.