Smoke dampers have blades of the __________ style.

Smoke dampers are specifically designed to control the movement of smoke in HVAC systems during a fire. The correct choice indicates that the blades of smoke dampers are of the multi-blade style. This design is instrumental in providing effective smoke control and prevention.

Multi-blade dampers have several advantages in smoke management. The multiple blades create a larger surface area that can close tightly to prevent smoke from passing through. The design enhances the damper's ability to block smoke, effectively sealing off areas to limit its spread. Furthermore, the arrangement of multiple blades allows for better distribution of air and leads to less potential for turbulence, making them more effective compared to single-blade options.

In addition, multi-blade dampers are often lighter and can be easier to operate as they distribute forces more evenly, allowing for smoother functionality when opening and closing. They also allow for more precise control over airflow when needed, contributing to overall system efficiency.

The other styles mentioned may not provide the same level of smoke control or practicality required in fire safety applications. For effective fire safety measures in HVAC design, using multi-blade smoke dampers is crucial to ensure compliance with safety standards and to optimize the safety of building occupants during an emergency.