6.6.9 Detection Systems

Beyond the measures discussed above, there is the option of using detection systems as part of the protective design package. In general, affordable, timely, and practical detection systems specific to all CBR agents are not yet available. However, for aerosol contaminants, nonspecific detection equipment can be employed to activate response actions should a sudden spike in aerosol concentration of a specific size range be detected. If the spike were detected in an outdoor intake for example, this could trigger possible response options such as damper closure, system shutdown, bypass to alternate air intake, or rerouting the air through a special bank of filters. Such protective actions could occur until an investigation was performed by trained personnel (i.e., check with adjacent alarms, and review security tape covering outdoor air intake). Unless foul play was discovered, the entire process could be completed within 10 minutes or less and without alarming occupants. The initial cost of such a system is relatively modest (depending upon the number of detectors and response options incorporated into the design), but the maintenance requirements are relatively high. Similar monitoring systems could be employed to trigger appropriate responses in high-threat areas such as mailrooms, shipping/receiving areas, or entrance lobbies. The approach could also be expanded to incorporate some of the newer chemical detection technologies, though the low threshold requirements may generate a substantial number of false positives. As technology progresses, detector availability and specificity should continue to expand into the general marketplace.

It is recognized that at this time, detection systems are not appropriate for many buildings. Consider using higher-efficiency filtration systems initially  and design HVAC systems so that detection systems can be easily integrated into the HVAC control package at a later date.