Abstract: An air filtration device comprises a housing assembly having at least one first mounting surface and having at least one air outlet, a blower positioned in the housing assembly for blowing air towards the at least one outlet, and a motor for driving the blower. At least one air intake has at least two intake mounting surfaces which are the same as each other and the same as the first mounting surface, wherein the air intake is attached to the housing assembly at one of the first mounting surfaces. At least one of the two intake mounting surfaces is positioned at an acute angle with respect to the other of the two intake mounting surfaces. Also, a muffler can be positioned adjacent the at least one air outlet. The muffler defines an opening operatively connected to the air outlet and the opening has a first cavity having a first volume, a second cavity having a second volume, and a third cavity having a third volume.