The factors determining the number and location of smoke detectors used for door release service are depth of wall section above the door and the numbers of doors.

The factors determining the number and location of smoke detectors used for door release service are depth of wall section above the door and the numbers of doors.

• A. Depth of wall section above the door
• B. Numbers of doors
• C. Both A and B
• D. Neither A nor B

Answer: (C)

When configuring smoke detectors for door release, the aim is to have detection occur in time to release held-open doors without causing unnecessary trips, covering each doorway effectively. The depth of the wall section above the door influences where a detector can be mounted and how wiring can be run, which affects both the practicality of placement and the sensing effectiveness right in front of the door. A deeper wall cavity provides more mounting options and can accommodate the detector in an ideal spot to sense smoke near the door, potentially changing how many detectors are needed and where they’re positioned. The number of doors matters because each doorway with a hold-open device needs reliable detection to ensure the door releases when smoke is present. More doors usually mean more detectors or distinct detection zones to guarantee that every door can respond promptly to a fire, rather than relying on a single detector to serve multiple, separate openings. So both factors—the wall depth above the door and the total number of doors—shape the required number and placement of detectors.

When configuring smoke detectors for door release, the aim is to have detection occur in time to release held-open doors without causing unnecessary trips, covering each doorway effectively. The depth of the wall section above the door influences where a detector can be mounted and how wiring can be run, which affects both the practicality of placement and the sensing effectiveness right in front of the door. A deeper wall cavity provides more mounting options and can accommodate the detector in an ideal spot to sense smoke near the door, potentially changing how many detectors are needed and where they’re positioned.

The number of doors matters because each doorway with a hold-open device needs reliable detection to ensure the door releases when smoke is present. More doors usually mean more detectors or distinct detection zones to guarantee that every door can respond promptly to a fire, rather than relying on a single detector to serve multiple, separate openings.

So both factors—the wall depth above the door and the total number of doors—shape the required number and placement of detectors.