Filter media, filter media packs, and filter elements

An air filtration media element for removal of particulates from an airstream, the element comprising:

• a) a first plurality of upstream flutes;
• and
• b) a second plurality of upstream flutes, the second plurality of upstream flutes arranged in a parallel flow configuration with the first plurality of upstream flutes;
• the second plurality of upstream flutes exhibiting differences in flute shape, flute size, flute height, flute width, flute length, cross-flute area, or filter media relative to the first plurality of upstream flutes;
• wherein the first plurality of upstream flutes and second plurality of upstream flutes have a common upstream face and common a downstream face and have sealing plugs at a downstream face of each flute;
• c) a plurality of downstream flutes having sealing plugs at an inlet face of each flute;
• and
• wherein when loading of the filter element with dust under substantially constant velocity, the first and second plurality of upstream flutes perform as follows:
• a) the first plurality of upstream flutes and second plurality of upstream flutes have substantially equal initial pressure drop from the upstream face to the) downstream face;
• b) the first plurality of upstream flutes has an initial velocity greater than the initial velocity of the second plurality of flutes;
• c) during dust loading:
• i) the pressure drop across the first upstream plurality of flutes and second upstream plurality of flutes remains substantially equal relative to one another while the velocity of the first and second plurality of upstream flutes is changing relative to one another;
• and
• ii) the velocity across the first plurality of upstream flutes decreases and the velocity across the second plurality of upstream flutes increases at least until the velocity across the second plurality of upstream flutes is greater than the velocity across the first upstream plurality of flutes.