The “Smart FFU” was covered in the January 2007 issue describing advances in both AC- and EC-based FFU products and the potential benefits available from these smarter FFU products. This article will extend the focus beyond the FFU to the interfacing system. The opportunities and options in the interface can be as simple as manual controls to sophisticated stand-alone systems or even interfaces that will tie into building management central control rooms. With smart FFU products being more readily available, the utilization of these units in “smart systems” is the logical progression.

For those systems desiring greater control and interaction with the FFUs the “smart FFU” provides a platform for greater flexibility and control as well as enabling maintenance and troubleshooting from centralized building management systems. It is this enabling factor that provides the value proposition for the “smart system.” This article will review the potential options and systems available to the customer when considering new or retrofit options to their cleanroom systems. Historical systems were customized and expensive, limiting their viability to large facilities and appealing to installationswhere installed cost was not the primary factor.

New system options now offer the customer a progression of smart options that match their feature priorities as well as their pocketbook. Along with greater options in smart FFU offerings, the smart system can be installed and cost effective for both small and large installations.

Figure 1. Cleanroom System Architecture

SYSTEM ARCHITECTURE
A cleanroom system (Figure 1) can be subdivided into 3 main areas:
1) Smart FFU
2 ) Local control/PLC/router
3) Computer (PC) or building management system(BMS)

With a “smart FFU” in place, each unit is now armed with some form of control and communications to an outside control scheme. The fan can often self-regulate or respond to an external command. Possible expectations of this of this “smart FFU” are:
• Adjust speed to optimize clean space (basic)
• Compensate for room/environment changes
• Monitor status of FFU (advanced) A “smart system” will capitalize on the “smart FFU” and add additional benefits to the user:
• Allow for system set-back to save energy
• Provide for ongoing adjustments to maintain compliance
• Provide for emergency shut-down
• Monitor unit performance for maintenance requirements
• Collect data for regulatory purposes
• Reconfigure