Standard and Custom Filter Fan Units (FFU’s)

Standard units come in 3 basic sizes, nominal 2’X2′, 2’X3′ and 2’X4′.

The standard units come in 3 basic sizes
23 5/8”W X 23 5/8”L X 9”H (nominal 2’ X 2’)
23 5/8”W X 35 5/8”L X 9”H (nominal 2’ X 3’)
23 5/8”W X 47 5/8”L X 9”H (nominal 2’ X 4’)
For sizes other than the 3 standard ones, the customer selects their preferred size. The sizing tolerance of the FFU can either be designed to +0”/- 1/8” or +/- 1/16”, depending on the mounting detail. Information about picking the tolerance of the FFU would be designed to is contained in the following passage titled true sizing versus military sizing (pdf).


Custom sizes
Space on the top of production tools is very valuable and so most Fan Filter designs are customized to the exact size required, to maximize space utilization. The smallest FFU we currently have in production is 8”W X 8”L X 9”H. Smaller units, down to 4” X 4”, could be designed but would have very limited air output capacity. The largest unit we have in production is 24”W X 84”L X 13”H, however larger units could be made.