Which of the following dimensions is critical for the installation of a smoke detector?

The critical dimension for the installation of a smoke detector is the centerline alignment with doorways. This alignment is important because smoke detectors are designed to detect smoke rising from a fire, and correct placement in relation to doorways ensures that the device can effectively sense smoke that may drift from a potential fire source.

By positioning the smoke detector properly, it maximizes its efficiency in detecting smoke that could enter the room through the doorway. This is especially relevant in residential and commercial settings where hallway access could allow smoke to travel rapidly towards the detector.

In contrast, while the height above ground, distance from windows, and proximity to heating vents are all relevant factors in smoke detector installation, they do not have the same direct influence on optimizing the smoke detection capabilities as proper alignment with doorways. Ensuring the detector is situated correctly in relation to doorways can significantly enhance safety and response time in case of fire.