What type of fire protection device will automatically recall elevators to the designated landing?

Elevator lobby smoke detectors play a crucial role in fire protection systems, particularly in high-rise buildings. Their primary function is to detect smoke within the elevator lobby area. When smoke is detected, these devices trigger an automatic response that recalls the elevators to a designated landing, typically the ground floor or a fire rescue landing.

This automatic recall is vital for several reasons. It ensures that elevators are not used during a fire, which could expose occupants to smoke and flames or lead to them becoming trapped. Instead, the elevators return to a safe location where emergency personnel can manage the situation effectively, and where others can safely exit the building if necessary.

The other options do not provide the same function. Smoke detectors provide general smoke detection but do not have the direct interaction with elevators. Heat detectors can notify of rising temperatures but also do not control elevator functions. Manual pull stations are designed for individuals to actively alert a fire alarm system but do not automatically control elevators. Thus, elevator lobby smoke detectors are specifically designed to ensure the safe recall of elevators during fire emergencies, making them the correct answer.