Where did you learn this? "of a square column of water 1 inch on each
side"

You make it sound like the density of water is dependent upon the volume of
it's container.



"Andy" wrote in message
oups.com...
Andy adds:

I have seen "10 inches" of water specified on a number of furnace
devices. I thought
I would just post what that means and what it means in psi.

10 inches of water means the weight of a square column of water 1
inch on each side which
is 10 inches high .


To determine the psi;
Remember 33.9 feet high (406.8 inches) and 1 sq inch on a side is
14.7 pounds

Therefore , 10 inches : (10/406.8) = (Xpsi/14.7) psi is
0.36 psi

11 inches : 0.40 psi

So, these pressures represent a very low, but still positive pressure.

Obiously, these very low pressures would be a pain to measure with a
gauge, but really
easy with a manometer , hence "inches of water"....
Andy