
Figure 11: Proper Air Conditioning Airflow and Rack Placement When Utilizing a High
CFM Rear Door
DVN 5000
Environmental Guidelines
22
24-10520-22 Rev. –
This document contains confidential and proprietary information of Johnson Controls, Inc.
© 2009 Johnson Controls, Inc.
Vent Sizing For Forced Air (Fans)
To avoid “starving” the forced airflow, provide an adequate intake venting area. The
following are minimum recommendations on the number of rackspaces of venting
needed – more venting is better, if properly placed. See the diagrams elsewhere in
this document for proper (and improper) vent placement.
Assumptions:
1. Rackmounted vents have 68% of open area.
2. Does not include equipment with front-intake (less venting is required if
“series” conditions are present from the front-intake fans in equipment; see
“Vents, Fans, And Equipment Layout” on page 26 for more information).
3. 4-inch fans deliver 95 CFM.
4. 10-inch fans deliver 550 CFM.
5. H10-inch (High-output) fans deliver 825 CFM.