What is the distance range for a wall-mounted detector from the ceiling?

The distance range for a wall-mounted detector from the ceiling is typically specified as being between 4 to 12 inches. This range ensures that the detector operates effectively by optimizing its sensitivity to the environment, such as the airflow and potential fire or smoke movement. If a wall-mounted detector is installed too close to the ceiling, it may not detect smoke or heat efficiently due to the stratification of air layers, where cooler air remains near the floor. Conversely, positioning it too far down may expose it to obstructions that could also impede its function. Therefore, installing a detector 4 to 12 inches from the ceiling strikes the right balance for optimal operation and compliance with safety standards.

While the other options present different ranges, they do not align with the recommended installation guidelines that prioritize effectiveness in detection while minimizing false alarms.