by Al Colombo [e-mail author]
Life safety is one of the most important elements associated with buying or building a new business or home. Prospective buyers are likely to insist on smoke protection and carbon monoxide (CO) detection when considering a new purchase. This is especially true in residential structures where smoke often kills before the flames reach the occupants or where CO can severely injure or kill when it goes undetected.
Nick Markowitz, owner of Markowitz Electric Protection of Verona, Pa., remembers one recent example in Penn Hills, Pa., where it paid off to have life safety as a focal point.
«A 5-year-old boy set fire to his sister’s closet using a lighter. A nearby smoke detector detected the fire, warning the household of the problem and enabling everyone to successfully evacuate without injury,» says Markowitz, who cites another example in an institutional campus environment.
«At Holy Family Institute in Emsworth, Pa., a CO detector near the boilers went into alarm,» Markowitz says. «It was found that a special energy savings unit installed inside the boiler fire stack malfunctioned, preventing CO from escaping.»
The local fire department immediately investigated, finding the problem. Because of the CO detection system that Markowitz installed, Holy Family administrators have a lot to be thankful for, as do the residents who are alive because the system worked so well.
Of course, there is always room for improvement when it comes to life safety, especially in the area of fire detection. Probably one of the primary ways the industry is improving is in the area of new fire detection technologies and sensors.
There were more than 1.5 million fires during 2004 and nearly $10 billion was lost in property damage, as reported by the National Fire Protection Association (NFPA) of Quincy, Mass. Of these 1.5 million fires, 526,000 involved structures, and 410,500, or 78 percent, took place in homes. In terms of human casualties, 3,900 people lost their lives due to fire that same year.
We will discuss some of the new life-safety sensors responsible for early warning of fire, property protection and the preservation of lives by the early detection of carbon monoxide (CO). We will also talk about the technology behind each one so security dealers and systems integrators understand them better. This will hopefully enable them to better match applications to the right technologies when engineering and selling these products.
Wireless Smoke Detectors Simplify, Speed Up Installations
Throughout the years, smoke detector technology has advanced by leaps and bounds. Early smoke detectors were dependent on the use of a separate power supply and initiating circuit, which the industry has come to call the four-wire method. In time, this changed as manufacturers combined these two circuits into one, providing what we now call the two-wire method. The impetus for consolidation relates to the need to reduce the number of necessary conductors, and the time it takes to install and connect them to devices.
The current trend, says Richard Roberts, product manager of the security business unit of Systems Sensor of St. Charles, Ill., is wireless detection. This, and the need for an even more installer-friendly detector, prompted System Sensor engineers to come up with an entirely new approach to smoke detection that addresses ongoing problems encountered by dealers. Thus, the W3 Series wireless smoke detector line was born.
Besides providing wireless connectivity with fire alarm panels, System Sensor’s new-generation smoke detector line has some unusual attributes that promise to save fire alarm companies money.
«During the past five to six years, we have seen a trend in smoke detector manufacturing toward wireless. Obviously, it’s easier to install wireless and more cost-effective in applications where it’s difficult or impossible to run conductors to them,» says Roberts. «We’re now working on a next-generation smoke detector designed to lower the installation, testing and maintenance costs for the security professional.»
The smoke detector itself uses a base to which a smoke head fastens. Typically, current models require the smoke head to be perfectly aligned with the base, which takes time. This assures that the base and head mate so a proper connection occurs and the head remains securely fastened to the base. The last thing an installer needs is for smoke heads to loosen and fall off their bases. System Sensor’s new-generation smoke detectors do not rely on perfect alignment. Instead, they have what Roberts calls a «Stop-Drop ‘N Lock» feature. «Using our Stop-Drop ‘N Lock, the installer doesn’t have to align the detector head with the mounting base,» says Roberts. «Just twist the head, and it will fall into the mounting base and snap into place. Because the head doesn’t have to be aligned with the base, this saves time, which saves the installer money.»
Installation is also a snap because of a new installation and removal tool, which can be administered by attaching it to the end of a broom handle or dowel rod, for example. The head can be easily removed or fastened to the base with a twist of the hand, eliminating the need of a ladder, which also saves the installer and service technician time.
Sensitivity testing can also be performed more easily and quickly using an infrared-based sensitivity tool that System Sensor can provide. The reader displays the detector’s sensitivity in terms of percent-per-foot obscuration. It will then display a text message that corresponds to the reading. The word «Good,» «Service» or «Replace» will be displayed, depending on the sensitivity measurement. This reader meets NFPA 72 requirements for testing of system smoke detectors.
Detectors Designed for Challenging Locations, Aesthetics
There are areas where it is difficult to provide fire detection because of environmental factors, such as excessive humidity, dirt and/or dust. Aesthetics is another problem that often stymies installers as they make an effort to work with interior designers and their clients.
Manufacturing plants are locations where false alarms can easily occur when a security dealer uses a detection technology that does not lend itself well to conditions at a particular location. This can result in false alarms, which are disruptive to operations and cause the client’s bottom line to suffer – especially when they occur on a regular basis. Traditional spot-type detection will not always work in such instances.
Bosch Security Systems of Fairport, N.Y., recently developed a rather ingenious smoke detector technology that addresses the issue of aesthetics while offering some relief in difficult environments. An application example would be commercial laundries where lint and other particulates can gradually build up inside the smoke chamber of traditional spot-type smoke detectors, eventually causing the aforementioned and dreaded false alarms.
Bosch’s FCP-500 Series smoke detector is installed flush to the ceiling so it’s hardly noticeable, which is ideal in places where aesthetics are important. To make a flush detector, the internal smoke chamber – which traditional smoke detectors rely on – had to be entirely eliminated.
«We’ve removed the chamber portion from our FCP-500 Series smoke detectors. We essentially have a flat plate that has two pairs of emitters and receivers in them. We create a virtual chamber just below the surface of the plate,» says Tom Hauder, fire products marketing manager with Bosch.
In other words, Bosch has found a way to use the open area immediately underneath the detector to monitor air for smoke, instead of drawing it into a smoke chamber inside the detector itself. Because there is no air chamber inside the detector to gather lint and dust particles, there is no need to clean it, which is a huge plus.
Another aspect of Bosch’s flush smoke detectors is the addition of a CO detection element, which is used to adjust the sensitivity range of the smoke detector. This relatively new approach hinges on the fact that all fires create CO, and often in relatively huge quantities prior to a notable open flame or smoke. By adjusting the sensitivity in this manner, false alarms are more easily averted.
«We are the only detection manufacturer that UL allows to have a detector at 8 percent per foot obscuration under normal conditions when the norm is 4 percent. We do this to avoid false alarms,» adds Hauder. «The CO element is not a replacement for a CO detector for life safety, but we use it to adjust the sensitivity of the detector.»
Under normal conditions, the FCP-500 operates at a sensitivity of approximately 8 percent. However, when the CO element detects CO, it adjusts the sensitivity to 2.5 to 3 percent, which is typical for traditional smoke detectors and smoke alarms.
Early Warning Systems Constantly Draw in Air to Sense Smoke
There are cases when even an ionization spot-type smoke detector cannot detect quickly enough for some applications. This can be a problem in special hazard applications. One technology that may help is an air-sampling smoke detection system, like the VESDA LaserFOCUS manufactured by Vision Systems of Norwell, Mass.
«This is an active system that is constantly drawing air from the environment through numerous sampling points,» says Paul Nelson, technical services engineer with Ansul of Marinette, Wis., a division of Tyco Fire & Safety. «This is a very flexible detection system that can be used in dirty industrial environments all the way to clean environments, such as computer rooms and clean rooms.»
Nelson says the VESDA LaserFOCUS system has even been used in coal-fired power plants where coal dust is often thick in the air. Nelson says this particular detector is the earliest of the early warning systems in the detection of smoke. And yet, according to Nelson, the false alarm rate is extremely low.
The VESDA system employs a network of plastic piping that brings air samples from various points in the environment into the main detection unit. Small portions of the air samples are then subjected to a laser beam from which an optical sensor is able to view light scattered by the smoke particulates inside the chamber. According to Nelson, in a relatively clean environment, the filter in the VESDA can last up to two years.
There are two ways to interface a fire alarm panel with the VESDA line. The first is a Form-C relay, and the second is data via RS-485, also called VESDAnet. The system also supports networkable relay modules and remote displays. Each detection unit contains an RS-485 repeater, which means they can be spaced up to 4,000 feet apart. For large jobs that warrant the earliest warnings, this is the way to go.
Integration with other control systems, such as fire alarm controls and computer management systems, is also possible using a high-level interface that also converts RS-485 to RS-232 for easy connection to a PC-based head-end.
System Shuts Off CO Source to Save Lives
Tremendous advances have also been made in CO detection technologies the past few years. According to Geoff Winters, president and CEO of UltraGuard/ECS in Greenwhich, Conn., the three basic CO detection technologies – biomimetic, electrochemical and semiconductor – are quite effective at detecting CO, thus saving lives.
«The industry should try to avoid knocking the other guy’s CO technology because they are all good at this time. The strongest thing you can do to help our industry is to acknowledge that all of them are reliable,» says Winters. What makes UltraGuard’s CO detection product so unique is that it’s a system and not just a group of individual CO detectors. The system is capable of shutting down the source of CO after detection takes place.
According to Joe Oliveri, vice president of sales for UltraGuard, the 12V control panel will handle up to 20 CO detectors. A new version, now undergoing UL testing, will operate on either 12V or 24V and will accommodate up to 40 CO detectors. Control over the CO source is attained using a Form C relay built into the CO control panel itself.
«Once our system has detected CO in the atmosphere, our control panel will shut down its cause, which is usually a furnace, boiler or gas-fired hot water tank,» confirms Winters. «A half-second after detection occurs, our system will stop the source of the CO, giving people a chance to evacuate the facility.»
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Al Colombo is a technical writer in the electronic security and fire protection markets, providing technical direction for security dealers since 1986. Visit him at www.securitymission.com.
by Al Colombo [e-mail author]