Which Class is characterized by CBRN filter units being fully integrated with the existing HVAC?

• A. Class 1 Full Integration
• B. Class 2 Partial Integration
• C. Class 3 Expedient
• D. Class 4 Secondary Enclosure

Answer: (A)

The main idea is how CBRN filtration is incorporated into the building’s air handling. Fully integrated with the existing HVAC means the CBRN filter units are built into or connected directly to the central air system so all supplied air passes through the CBRN filtration as part of normal operation. This setup provides uniform protection across all spaces, centralized control, and avoids the need for separate enclosures or portable units. It’s the best match because the description specifically calls for integration with the existing HVAC, implying a single, seamless filtration path for the entire building. Other approaches describe different arrangements: partial integration leaves some air handling unprotected or inadequately filtered; expedient denotes temporary, field-made filtration solutions; and a secondary enclosure uses a separate, self-contained space with its own filtration rather than the main HVAC path.