When sheltering people in place, which action should be taken regarding heating, ventilation, and air conditioning systems?

When sheltering people in place, which action should be taken regarding heating, ventilation, and air conditioning systems?

• A. Open windows for air exchange.
• B. Close all heating, ventilation, and air conditioning systems.
• C. Keep heating, ventilation, and air conditioning systems running.
• D. Periodically open the doors to relieve the pressure.

Answer: (B)

During sheltering in place, the priority is to limit indoor exposure by preventing outside air from bringing in contaminants and stopping the indoor air from circulating through the building. Shutting down heating, ventilation, and air conditioning systems accomplishes this by stopping air exchange with the outdoors and preventing contaminants already indoors from being recirculated through ducts. Keeping the HVAC running would spread any contaminants, while opening windows would introduce outdoor air that could be polluted. Periodically opening doors to relieve pressure would create uncontrolled air movement and potential infiltration of contaminants. For these reasons, the best action is to close all HVAC systems to maintain a sealed, safer environment.

During sheltering in place, the priority is to limit indoor exposure by preventing outside air from bringing in contaminants and stopping the indoor air from circulating through the building. Shutting down heating, ventilation, and air conditioning systems accomplishes this by stopping air exchange with the outdoors and preventing contaminants already indoors from being recirculated through ducts. Keeping the HVAC running would spread any contaminants, while opening windows would introduce outdoor air that could be polluted. Periodically opening doors to relieve pressure would create uncontrolled air movement and potential infiltration of contaminants. For these reasons, the best action is to close all HVAC systems to maintain a sealed, safer environment.