Duct Smoke Detector Installation Requirements

Duct smoke detection nfpa 90a code requirements there are exceptions to the two basic requirements.

Duct smoke detector installation requirements.

Duct smoke detectors alarms and the code. With power source de energized and the smoke detector not installed wire all connections per engineering drawings. To ensure correct operation install the duct detector using the following guidelines. The duct detector should when possible be located a minimum of six duct widths downstream from a source of turbulence bends inlets or deflection plates.

Return air smoke detectors are not required when there is a protection of. For proper air sampling duct pressure should be a minimum of 0 01 inches of water. Duct detectors aren t a replacement for room sensors. Smoke alarms should be installed at least 10 feet 3 meters from a cooking appliance to minimize false alarms when cooking.

The international mechanical code imc specifies that if the space is air conditioned and the a c unit is over 2 000 cfm a duct smoke detector is required to be installed in the return air duct. Install the duct smoke detector on a flat section of hvac duct between six and ten duct widths from any bends or obstructions. If the duct system is designed to carry more than 2000 cfm 5 tons nominal of air you need one in the. Mount smoke alarms high on walls or ceilings remember smoke rises.

Ventilation fan systems used to remove air from the inside of the building to the outside of the building. Standard location when factory mounted will be on the side opposite the damper actuator. Energize the duct detector. A duct smoke detector should shut off a typical blower and fresh air and turn on the exhaust.

Refer to the applicable figures below depending on your duct housing model number. Detector installation 5 1 verify air flow direction and velocity model d4120 detectors are designed to be used in air handling systems with air velocities of 100 to 4000 feet per minute. Wall mounted alarms should be installed not more than 12 inches away from the ceiling to the top of the alarm. Refer to nfpa 90a 72 and 101 for more information.

At these locations air flow is less turbulent and the air smoke mixture should be more homogenous. 2 6 p n 3101210 rev 02 iss 28jan13.