For a popular nightclub with a nuisance alarm problem, the new Advanced Multi-Criteria Fire Detector increases fire response and accuracy while saving the club thousands.

Imagine it’s Saturday night at a packed entertainment venue. The dance floor is full of people dancing to a popular national DJ with music synched to multi-colored laser and light effects, and several private rooms are at full capacity hosting VIPs, fundraisers or other private parties. The rope line for the public dance club stretches a block down the street, with people waiting up to an hour for a chance to spend a memorable evening out with friends.

Then, a smoke effect designed to enhance the laser light show reaches a standard smoke detector set above the dance floor. Suddenly, the entire complex goes into full fire alarm…the music and effects are cut off and replaced by the blare of a fire alarm, fire strobes and floodlights. Patrons rush toward the exits and out onto the busy street.

More than an hour later, fire services have checked out the building. There’s no fire and no damage. But now the rope line is empty, evacuated patrons have moved to a club down the strip and angry party hosts are demanding their money back from the club’s management. In all, the club has lost thousands of dollars as the result of a single nuisance alarm.

Scenarios such as this can be quite common. Traditional fire detection technologies, which excel at detecting fires and providing adequate escape times in most applications, often struggle to maintain appropriate fire sensitivity and accuracy for atypical and challenging applications. Because of this, venues with persistent nuisance conditions, such as theater smoke and fog effects, must make difficult and costly decisions about how to provide the high-quality entertainment experience their customers have come to expect, while maintaining the highest level of safety possible.

In fact, this is the exact issue that was faced by one popular nightclub. The following case study shows how advanced fire detection technology enabled this club to overcome its difficult and costly fire detection challenges.

Case Study: The Rumba Room

The Rumba Room is an upscale Hollywood nightclub. Part of a multi-building, multi-story entertainment complex, this 25,000 square foot, 1,000-patron capacity Latin dance club boasts two levels and two dance floors featuring state-of-the-art sound and lighting, including fog and smoke effects.

Unfortunately, the club’s theatrical smoke set off the facility’s smoke alarms on an almost nightly basis. To make matters worse, the smoke would trigger a full-blown alarm that would require the evacuation of nearly a quarter of the entire entertainment complex, including the restaurant below the club.

Like the Rumba Room’s situation, there are many fire system applications that stretch the capabilities of traditional fire detection technologies beyond their capacity — either because nuisance conditions are present or because even a small amount of downtime relating to nuisance alarms can have devastating financial effects. That’s because fire detection devices must balance two competing needs: rapid response and accuracy.  Typically, increasing performance in one of these factors reduces performance in the other: Improving response times increases nuisance alarms. Conversely, reducing nuisance alarms increases response times.

Newer construction and furnishing materials exacerbate this problem by increasing fire acceleration, which reduces escape times. Faster-burning environments require higher sensitivity from their fire detection systems to allow proper egress and better property protection.

Another issue is that different fire types produce different levels of smoke, heat, carbon monoxide (CO) and light. For example, as Figure 1 shows, a heat detector excels at detecting flaming alcohol, but responds slowly to smoldering fires. Similarly, ion detectors are very sensitive to flaming fires, while photoelectric detectors are better with fires that produce more smoke particulate. Although multiple types of detector technologies are available, each will be best suited for some types of fires, while being either less accurate or less sensitive for other fire types or conditions.

Problems arise when an application demands too much of a detector in either sensitivity or accuracy. Sometimes, this imbalance can cause such poor performance that the fire detection system itself can become a liability.

This was certainly the case with the Rumba Room.

The fog and smoke effects were demanding a level of accuracy from the traditional photoelectric detectors over the dance floor that was well beyond normal.

With each alarm resulting in one to two hours of downtime, including evacuation, fire department arrival and walkthrough and clearing of smoke, lost revenues from each instance could exceed tens of thousands of dollars.

The Rumba Room, after purchasing and experimenting with several different fog and smoke machines with similar results, was forced to receive special permission to set all of its smoke detectors to supervisory mode. This required independent verification of a fire before sounding an alarm, ultimately slowing fire response and incurring additional liability.

Advanced Technology Improves Detection

Then, in 2009, Callide Technical of San Dimas, Calif., was contracted to upgrade the fire safety system of the entire entertainment complex. The Rumba Room posed a particular challenge for Callide.

“With all the fog and smoke effects, the existing photoelectric detectors were constantly going into alarm,” said Tom Johnson, a Callide Technical principal. Callide agreed, however, that maintaining the fire alarm system in supervisory mode was an unsatisfactory solution in terms of liability risks and costs, and the resulting delay in fire response.

Callide proposed installing the System Sensor Advanced Multi-Criteria Fire Detector, branded as IntelliQuad™ through Notifier^®, because of its ability to quickly respond to actual fires while maintaining high immunity to nuisance conditions.

How It Works

The Advanced Multi-Criteria Fire Detector combines four detection methods in a single housing to measure all four products of a fire — heat, smoke, carbon monoxide, and light. If one of the sensors detects a fire condition, the onboard intelligence verifies the condition with another sensor before generating an alarm.

These four sensors enable the detector to respond to multiple fire types in a wide range of applications and reject nuisance conditions. The detector includes a powerful central processing unit that enables it to process intelligent algorithms to provide extended drift compensation and to vary sampling rates, alarm delay and sensitivity based on environmental readings. The result of years of research and then extensive testing, this dynamic adjustment allows the detector to normally operate at a very high immune level and then become very sensitive to fires once it senses the proper characteristics.

For example, the baseline photoelectric sensitivity might be set to alarm at particulate concentrations of 4 percent per square foot. But unlike a regular photoelectric detector, the Advanced Multi-Criteria Fire Detector can ignore particulate concentrations well beyond 4 percent if no other fire conditions are present. At the same time, if other fire conditions are present, such as CO or heat, the detector doesn’t wait until 4 percent concentrations are present; it can respond more quickly.

Correct Detection Brings Results

The Rumba Room agreed that the decrease in lost revenues and liability and increase in fire response times justified the use of the more advanced technology, especially if it would allow them to operate the club with the smoke and light effects that contribute significantly to its unique ambience and appeal.

Callide installed about 25 Advanced Multi-Criteria Fire Detectors to cover the dance floor areas on both levels. Installers wired the detectors like any other smoke detector. A small amount of additional programming set the detectors at the correct sensitivity level for the environment.

“Labor costs were basically a wash,” said Johnson. “While the installed cost for these detectors was about 15-20 percent more than a typical photoelectric detector, the Rumba Room was losing more money in an hour of downtime than 50 times the cost difference.”

Once installation was completed, the Rumba Room was able to return all of its detectors to alarm from supervisory. And what happened with the frequent nuisance alarms?  Johnson concluded, “These detectors have been operating for several months now without a single nuisance alarm.”

Related stories:
Advanced Multi-Criteria Fire Detector: Ideal Applications
Research Aims to Increase Photoelectric Detectors’ Sensitivity to Flaming Fires

Tags: Multi-criteria Detection

Posted in Commercial, Cover Features, Intelligent Detection, Winter 2009