Why should a mechanical contractor install a duct smoke detector in every building above 2,000 CMF.

Do you know the history of why duct smoke detectors are required by code and regulated to a NFPA standard?

The inception of these life-saving devices traces back to a tragic incident at the MGM Grand Hotel and Casino in 1980. This event spurred the development of air sensing solutions to mitigate the impact of fires caused by faulty ventilation systems.

The MGM Grand Hotel Fire

On November 21, 1980, a devastating fire swept through the MGM Grand Hotel and Casino in Las Vegas, claiming the lives of 85 people, primarily due to smoke inhalation. The root cause was identified as faulty smoke dampers within the ventilation duct network. Smoke circulated through the hotel’s air conditioning system, exacerbating the spread of poisonous gases. The incident prompted a re-evaluation of fire safety guidelines and codes in the state, leading to crucial reforms.

Fireman on ladder

Duct smoke detectors are a critical solution to address the spread of smoke in a building. In the event of a fire, these detectors play a pivotal role in shutting down the HVAC system, thereby preventing the further circulation of toxic gases and saving lives in the process.

HVAC contractor repairing ceiling air conditioning unit
HVAC Duct Smoke Detector functions

Duct smoke detectors operate by sampling air currents in air handling equipment to identify the presence of smoke. Once detected, the device takes immediate action by closing the dampers on the ductshutting down air handling units, fans and blowers to prevent the spread of smoke, and triggering an audible and visible signal. This swift response is essential for containing the fire and minimizing its impact.

Duct Smoke Detector installed on ducts

Smoke Detection Codes & Standards

In the United States, the installation and maintenance of duct smoke detectors are regulated by the NFPA90A Standard and the International Mechanical Code (IMC). Generally, systems with a CFM (Cubic Feet per Minute) of 2,000 or more require the installation of duct detectors downstream of air filters and ahead of any branch connections from the Rooftop Unit (RTU). Adhering to these standards ensures a uniform and high level of safety across commercial HVAC systems.

APC has been proudly manufacturing Duct Smoke Detectors since the very beginning of the current guidelines: check out our Duct Smoke Detection Guide for a complete description of what a commercial smoke detection system requires.

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