Pressurizing

Fans for pressurization are usually used to keep the space from allowing any air to leak into the surrounding space.  This is often desirable in computer or control rooms in chemical or dirty environments.  If personnel are to be present in the pressurized space, the air must be filtered and climate controlled before supplying the air into the surrounding space.  Fans are normally supplied with variable-speed controls to idle the pressurization down to a preset level during times when the room is not occupied by personnel.  NYB Junior, General Purpose, and AcF/PLR/BC clean air designs are recommended for these applications.