AIR SAMPLING SMOKE DETECTION SYSTEMS IN THE UNITED STATES
As mission critical fire protection experts, we're always looking for ways to educate our audience on all-things mission critical. In our latest webinar series, we teach you about air sampling smoke detection systems in fire suppression with a special feature on MCFP insights relevant to specific regions across the U.S. Now you can access this webinar on-demand to gain more insights on air sampling smoke detection systems in fire protection.
WHAT’S IT ABOUT?
This overview of air sampling smoke detection by Lee Kaiser—ORR Protection System’s VP of Engineering—discusses the importance of early detection and investigation, air sampling products and best practices, and appropriate applications in mission critical facilities. Detector testing and maintenance will also be reviewed.
WHAT WILL YOU GET?
Watch the webinar or read through the content below to learn more about air sampling smoke detection systems in fire suppression. In each Air Sampling Smoke Detection webinar, Lee will be followed by regional experts discussing the use of air sampling smoke detection in your area. These experts will talk about the most popular smoke detection products, regional certifications needed for install and maintenance, the future of air sampling fire protection in your region, and more.
WHO SHOULD WATCH?
Anyone in charge of the fire protection for a facility in the U.S. will find this webinar timely and important!
Table of Contents
About ORR Protection
Gross Stages of a Fire
Types of Fire Detection
Technologies for Fire Detection
Air Sampling Smoke Detectors + How They Work
Vesda Detectors: What's Right for You
Inspection, Testing & Maintenance
AIR SAMPLING SMOKE DETECTION [WEBINAR TRANSCRIPT]
About ORR Protection
Paul Nelson: Good afternoon. My name is Paul Nelson. Lee Kaiser's going to be coming to you in just a few minutes and talking to you about air sampling and early warning detection for fires. I'm going to take just a couple minutes to tell you a little bit about the ORR Corporation and what you can expect from us. We are a mission critical fire protection company. We focus on fire alarm detection and suppression. ORR's been around since 1971, and today we're the largest privately owned fire and safety company in the country. We protect about $30 billion worth of assets across the county. We're a nationwide company. You can see that we really started out on the East Coast of the United States and expanded west, and we continue to expand into other areas each and every year. We service today about 30,000 fire protection systems across the country. We do a lot of different types of suppression systems. It could be FM200, some of the new gases, Novec 1230. We do water mist, high pressure, low-pressure water mist, CO2, so there's a variety of different products that we can provide you on the suppression side.
And here's some of our premier partners that we work with. We really like to try to focus in on the service side of our business 'cause that's really the nuts and bolts of what we do. We have experience where it counts. Our average technician has over 8 years of experience. We can provide you a single point of contact. We have manufacturer-trained technicians, and our goal is, when we come out, to fix it the first time that we're on site. And we're ISO 9001 quality certified coast to coast, and what that means is the quality of work you're going to get, whether it's in California, New York, down into Florida, it's going to be consistent across the country. And, obviously, we're available 24/7.
On our online reporting side, we provide you with online reporting. We call it NetSITE. And, essentially, all you need to do is be able to log in. And, essentially, you're going to be able to pull down any required information that you have on the fire reports that you have, and, essentially, it'll give you all the information from those inspections that we've completed.
One of the things you'll want to do is to check out our blog. Go to our website and click on our blog. And, essentially, you have the opportunity to pull down articles, whether it be on common problems in the fire protection industry, information on hot aisle/cold aisle or Halon, whatever it may be.
I'd like to introduce our speaker for the day, Lee Kaiser. He's our vice president in charge of engineering. Lee is not only a PE, but he's an FPE, fire protection engineer. Lee currently is chairman of NFPA 75, and he also sits on the board of directors for our association, Fire Suppression Association. And he is also a 21‑year veteran for a volunteer fire department. So, without further adieu, Lee.
Gross Stages of a Fire
Lee Kaiser: Hello. My name's Lee Kaiser. I'm vice president of engineering for ORR Protection, and today we're here to talk about air sampling smoke detection. When we talk about air sampling, it's important to talk about how fires grow. And so, on the slide here, we've got a chart that kind of talks about the gross stages of a fire.
When fire starts, we call that the incipient stage, and low levels of smoke are present, maybe so low that we can't see it with the human eye. As the fire grows, smoke will become visible, and that's where we'd expect the fire alarm system to activate. And then, finally, as the fire grows in a space, heat will build up, and with that intense heat we'd expect to suppress that fire from whatever type of system is there. In a lot of buildings that's going to be fire sprinklers. But, as we talk about this, air sampling smoke detection, we spend a lot of time talking about fires in their incipient stage where we want to investigate and head the fire off at the pass.
So what would you do if you had time? Air sampling smoke detection can help give you that time. During the incipient stage of a fire, we will seek out some responsible human response. We want to investigate what's happening but don't necessarily evacuate the building because we're not at a life safety threatening level of smoke. It gives the owner of the building time to respond before the fire department has to, and then it could prevent unnecessary discharges of the fire suppression system, if we can control the hazard during that incipient stage. That early detection gives us options in the building. We can respond proportionally to the known level of risk. If there's spaces that are critical and use air sampling smoke detection, we may want to get there fast because we know that if the fire gets away from us and flames do break out, that can be quite critical to our operation. So we recommend everybody to try and investigate during the incipient stage of a fire so they can manage the risk before it escalates.
One of the techniques to help manage the risk is to investigate with thermal imaging, shut down processes that may be overheating, turn off equipment that's causing the problem, and then have portable fire extinguishers available so you can manually extinguish that fire before the building's fire suppression system needs to.
As we talk about investigating, one tool that we like to talk about whenever we talk about air sampling is thermal imaging cameras, and there are consumer-grade thermal imaging cameras that you can obtain quite economically for you to be able to look for overheated equipment. And a lot of times, where air sampling smoke detection systems are installed, that's the type of hazard that we're going to experience is overheated electrical equipment. And so we can use thermal imaging cameras to look for electrical components that may be overheating that may be the source of the smoke that we can't yet see.
This picture that I'm drawing up here is a picture of our building here, and that camera is a thermal imaging camera that gets installed on a smartphone, and it's looking at an electrical panel that has a couple of circuits that are actually overloaded. And that was happening in our corporate data center, and we did an electrical project to spread out that load so that we wouldn't have a future failure and shut down that equipment or, much worse, have a fire start at that electrical panel. So that's real world experience from our own company.
With manual intervention, once we find things, for small fires, we recommend that you just try to handle it with a fire extinguisher. Locate the thermal condition. Shut down the process. If there's any flames, use that fire extinguisher.
And so some guidance for fire extinguishers in spaces that usually use air sampling smoke detection, use a clean agent-type fire extinguisher or other clean fire extinguisher in that space so you don't ruin any electronics that may be in that space. Extinguishers should be spaced at 3,000-square-foot spacings, with a maximum of 75 foot of travel distance. And we recommend that those be located at room entrances so you can move towards an entrance, and, if the fire gets too bad, then you'll know where that exit from the room is. And then, lastly, as with all fire extinguishers, if you're going to have them in your building, they need to be serviced, maintained, and you need to provide training to the workers in that space so they know how to use them.
Types of fire detection
With air sampling smoke detection, there are three terms that may be new to you that we need to cover: standard fire detection, early warning fire detection, and very early warning fire detection. So, as we go from standard to very early warning detection, the performance expectation of the fire detection system goes up. This graph shows us that. On the left-hand side of the chart, we have the sensitivity, the smoke reading, and, along the bottom, we have the spacing of the detectors.
So down in the lower left-hand corner, we have very early warning fire detection where we are sensitive to smoke at 1 percent obscuration per foot is where it would go into alarm for a fire. And percent obscuration per foot is a measurement of smoke obscuration, smoke density, in a space, and that's how smoke detectors alarm for a fire, at different levels of smoke obscuration. And then the spacing for very early warning fire detection is at 200 square foot per detector or per sampling point. And so what we expect for very early warning, to achieve that level, we have sensitive equipment, and we have a dense spacing so we're better able to pick up that smoke quickly in that space to get that very early warning response.
Then we go to early warning where we're slightly less sensitive at 1½ percent obscuration per foot and a 400‑foot spacing. This is pretty common for non‑critical areas to specify early warning fire detection.
And then standard fire detection. This is what many of our normal building are, normal office spaces, normal retail spaces, hospitals, spacing at 900 square foot per detector and then activation for alarm at 2½ percent obscuration per foot. So we'd be able to see smoke at 1½ and 2½. At 1, we may just barely be able to perceive that light haze. And, in that case, our detector would be an alarm at that point.
Another thing that's important to understand with air sampling smoke detectors is the transport times. And so we're going to talk about how they work. But we are transporting air from sampling ports in the system back to the detector so the detector can measure for smoke, and the timing that we allow to do that, it's called the transport time. And for standard fire detection, we're allowed 120 seconds of transport time for the air to go from the farthest way sample port back to the detector. It shortens for early warning at 90 seconds, and at very early warning we want to bring that air back to the detector within 60 seconds. And understand that that transport time that's specified determines the air sampling pipe detection layout, so shorter times may require rooms to have additional detectors. So if you want to achieve very early warning fire detection with a denser spacing of sampling ports, you may have to have more detectors to protect that space.
Now, this chart is a little bit of an eye chart, but I want to talk to you about different areas and how they may use standard, early warning, and very early warning fire detection. And so we have a number of rooms called out on the left with the area of function that may be in a typical data center that has multiple functional areas within it, and that's sort of how we build standalone data centers today.
So, for the electrical distribution room, we typically see specified very early warning fire detection because the distribution of power is very important to the core function of a data center, which is data processing.
For battery rooms, it's critical to the reliability of the network, sometimes a concentration of combustibles with regards to the batteries but lower air change rate, so we often see early warning fire detection applied and specified for those rooms.
Generator rooms, also critical to the power path for backup power, and in those rooms we see early warning fire detection often specified.
In the server hall, then we go up to very early warning fire detection. That's the white space where the computers and the rack actually are and the data processing occurs. That's a good reason to protect that asset and have that higher level of detection for very early warning fire detection.
Then, when we go to administrative spaces where there would be people's offices and cubicles, some incidental storage, so we go down to standard fire detection because we still want to have detection in those spaces, but we just follow the normal codes and standards and have smoke detection but at that lowest level of smoke detection performance. Same with the loading bays or warehouses. This may be correct for packing and unpacking areas when we get new IT equipment into our data center.
And then, for mechanical spaces where we're using mechanical equipment to help cool the server spaces, then we bump back up because that's a critical space, and we go to early warning fire detection because we want to know about that space so we can investigate.
And then, finally, on this list is the air intake structure. If your data center uses or your facility uses outside air as part of the ventilation in the space, understand that air sampling smoke detection can be applied to the outdoor air intakes so that you can see any smoke coming into your space and possibly work that smoke detection into your sequence of controls so that you shut down ventilation when you're drawing smoke into your space so you don't bring that smoke in and threaten the components that are inside your building.
Technologies for fire detection
So technologies that can help us deliver standard, early warning, and very early warning. Across the top on this chart we've got an air sampling smoke detector. The way air sampling can be installed, it's very flexible. It can accommodate standard, early warning, and very early warning strategies inside your building.
Next is a laser spot detector. Laser spot detectors have been around. They use a laser chamber similar to what is in an air sampling smoke detector, but they're a passive device that wait for the smoke to get to it. They're often applied for very early warning specifications.
Next are photoelectric spot detectors. Those are the type of spot smoke detectors that we use today in all sorts of applications. They can be used for standard and early warning.
And then, last, beam detectors. Beam detectors are used for large open spaces, sometimes in spaces that have high ceilings. We see them a lot in atriums. They don't work as well as some of the other technologies to respond to smoke, but they can cover large distances, so we qualify those as standard fire detection.
And so then we see those same detector technologies on this chart where, from the bottom, we go from low to high technology and, left to right, low performance to high performance, and we sort of rank those along that chart.
air sampling Smoke detectors + how they work
Let's talk about what an air sampling detector is and how it works. An air sampling detector consists of a centralized detector mounted on the wall, usually where it can be easily accessed. And then out of that detector are ran a series of three-quarter inch CPVC air sampling pipes. And those pipes go out into the space and a lot of times to the ceiling, spread out across the ceiling, and then into those pipes are drilled holes. And on this slide you can see holes, and those holes are where the fan that's back in the detector sucks air back through those holes, into the pipe, and is carried back into the detector.
Now, in the detector there is a detection chamber that measures, is there any smoke in this air that's being brought back to me, and then how much smoke is in that air? So air sampling smoke detection allows us to do the technique of very early warning fire detection, and it can detect down at the incipient stages of a fire. But, as you'll see as we go along here, some of the qualities of an air sampling smoke detector allow it to detect fire over a broad range of conditions and then in a broad range of applications.
The last thing to say on this slide is that air sampling smoke detectors are active detection rather than passive detection, so air sampling detectors, because of the fan that's inside of the detector, is constantly actively sampling the air in the room and looking for smoke instead of waiting for smoke to come to it like other passive types of detection.
This is a fire growth curve, and it sort of shows you where technologies activate for a fire as a fire grows. So, to the left, we start with fires in the incipient stage, Stage 1, low smoke density in the space. And then, as it goes to the right, Stage 2 where there's visible smoke, that would first be where a conventional spot smoke detector would activate. Once flames are present, then optical flame detection would be able to see that fire. And then, when there's heat, then forms of heat detectors like rate-of-rise heat detectors, rate-compensated heat detectors, or even sprinklers. One of the most common ways that we detect using heat is a fire sprinkler. That's where they would activate. And so, when you look at this and you think about your space and its criticality to you, VESDA detection or air sampling smoke detection works in that first stage, and it'll work all along that continuum, but it can give us that early warning notification of a fire early on when the fire's small and still manageable.
Now, air sampling smoke detectors, specifically VESDA detectors, and VESDA's a brand name that I'm sure a lot of you have heard, they have multiple levels of notification, based on the buildup of smoke in a space. They have pre‑warning notifications and warning notifications where we actually have a life safety threatening condition. And so let's go through these.
At the top, we start with normal. That's when no smoke is being detected. Then we can set up alert and action. Those are increasing levels of smoke, but they're not life safety threatening levels of smoke, so we bring in a pre‑warning signal to the fire alarm system when we get to alert and action that usually comes into the panel as a supervisory. And then a responsible person that's responsible to check up on the fire alarm system as part of their routine, they see that there's smoke present, and they can start investigating at that point. Once we get an increase in the amount of smoke, then we get to Fire 1 level. That would be where we'd first activate the fire alarm system to evacuate the building. But then there's a second level for fire activation, Fire 2, that can be a less-sensitive level, and that can be used for multiple things, to track the development of the fire, to go back and look how it grew, or, also, to use it in a releasing sequence for a fire suppression system. Some applications we're aware of, they release once they get to Fire 2, and then they know that they've got a real fire in their building and it's worth releasing their system.
So VESDA detectors can answer some challenges.
So one challenge is poor access to get to the detectors to serve them. Well, with VESDA, we can have remote detector placement and locate that detector in a point that it can be accessed.
Poor longevity can be a challenge with smoke detectors. Well, with VESDA detectors, the way the optics inside the detection chamber are protected extends the life of that detector.
High-nuisance alarm rates. We know false alarms are a big problem for smoke detection systems. But, with VESDA, the multiple levels of alarm and the advanced techniques that we detect smoke in the air makes VESDA detectors very resistant to false alarms. In fact, out of all the service calls that our company does on VESDA detectors, false alarms are the least frequent one that we have for VESDA detectors.
Problem of vandalism and poor aesthetics for detectors. Well, VESDA detectors can be hidden. The sampling points can be discreet, and, while they're discreet and hidden, they're still actively detecting, so we don't have a detector on the ceiling for someone to see. Now that can be hidden, and we can discreetly avoid vandalism or poor looks, poor aesthetics.
Low environmental tolerance as a challenge. Well, VESDA detectors, because of their technology, are tolerant of temperate, humidity, and dust in the atmosphere.
And then problems addressing a broad range of applications. Well, VESDA, because of the creativity of the Xtralis company who owns VESDA, and the users of VESDA out there would know that VESDA detectors can be applied over a number of different challenging applications, and it's proved reliable in giving good performance over the years.
Vesda Detectors: what's right for you
Let's talk about some of the VESDA detectors out there. This is a picture of the VESDA product family. There are more that we're going to show. But this has, for a long time, been the product family, and there's a couple of these detectors that I want to highlight here.
The black and orange detector is the VESDA VLI. VLI standards for VESDA Laser Industrial. It's an air sampling smoke detector intended for industrial applications. It's built inside of a NEMA 3S enclosure, which is appropriate for many industrial spaces, so it's ruggedized. It has advanced filtration built into the detector to filter out dust that we expect to be present in a lot of industrial spaces where this detector is intended for. It has a primary failsafe filter and then a secondary HEPA filter that protects the laser. It has a larger aspirator. That means the fan inside of the detector. That larger fan allows more pipe length to be attached to the detector, and it's nearly double that of other air sampling detector models. That's important in many industrial spaces because we expect to have to run farther to get to an accessible location for the detector box and still detect farther away. Expect a lot of high ceilings and a lot of that transport to eat up the pipe length that we would have for that detector. It's a four-pipe detector, like a lot of the other large air sampling detectors, and it covers up to 20,000 square feet of space, depending on the hole spacing and detector spacing density.
Now, what's new for VESDA is they've replaced a lot of detectors in the laser series with the VESDA E series of detectors, so I want to talk about the VESDA E series. In this next generation of VESDA, the VESDA-E VEU and VEP are four-pipe, aspirating smoke detectors with area coverage up to 21,000-some square feet. They have a total maximum pipe length of 2,600 feet that can be attached to the detector. It has new field-replaceable components. That's new in the VESDA lineup. It offers the same VESDAnet networking that we're used to with the other VESDA detectors, but now it adds Wi-Fi connectivity, so that we can see the detector remotely with a handheld device and see what's going on with it, what's happening with airflows, what's happening with smoke obscuration the detector is seeing. Has a 20,000-event log inside of it, so we can watch what's been happening with smoke in our space, and then for those of you that are existing air sampling smoke detector users today that have the VESDA LaserPLUS detectors, the detectors with the blue face on the front, the VESDA VEU and the VEP are an easy upgrade from those old VLP detectors.
What's different inside the detector is the new detection chamber. So at the top upper right-hand side of the slide, we can see a picture. It's a cutaway picture of a VESDA Laser detection chamber. That's been revised for the new VESDA-E series into the Flair detector technology. So inside the new Flair detector, it's got a greatly enhanced sensor count over the previous laser detection chamber. There are over 330,000 sensors inside the Flair chamber and ten chip cameras that measure ten different unique parameters of the particulate that comes into the detection chamber, and so those new particle analytic processes allow for better smoke detection, allow to discriminate different types of smoke. We can tell with this detector if it's smoke from burning PVC insulation on wires through the wire trace analytics that can be installed on the detector. We can tell what kind of dust is in the space or the buildup of dust through the dust trace analytics, and then finally, if you have a space where you know diesel smoke is going to be in the space, such as if you were using VESDA detection inside of a warehouse, and the dock doors would occasionally bring in diesel smoke from the semi trucks outside, the diesel trace program can be enabled to discriminate between smoke from a fire in the warehouse and smoke from a diesel engine. So that's a new technology that we didn't previously have in the laser series of VESDA detectors.
So let's compare the VEP and the VLP detectors. So the black detector's the VEP, the everyday workhorse of the VESDA-E line, and the VLP is the detector there with the blue face. The VEP has greater sensitivity to smoke by 1½ times. Because of field-replaceable components and better optic protection inside, it's expected to last inside of the space by two times longer. Coverage and high airflow conditions can be greater by 10 percent and then has a lower power consumption per unit area using the VEP over the VLP.
Another detector in the VESDA-E lineup is the VESDA VEA. VEA stands for VESDA-E Addressable. This is a new concept in air sampling smoke detection where instead of three-quarter-inch CPVC pipes, now we run small-diameter, flexible tubes to the locations from where we're going to detect smoke in the space, but each tube is a home run back to the detector, and so let's explain that. The VESDA-E VEA is a new approach to everyday smoke detection. It's intended to compete in the marketplace where photoelectric spot detectors currently hold the market share. It's a centralized detector, like other VESDA detectors, offering new things: centralized point of maintenance for faster testing of the detector on an annual basis; single point wiring, we don't have to run conduits and wires to all the sensing locations, and it's still, like VESDA detectors, it gives us multiple alarm thresholds. Now, it's not as sensitive as a traditional air sampling smoke detector, traditional VESDA unit. It's intended to compete in the everyday smoke detection space, but instead of running conduit and wire, now we're running flexible tubes to sampling ports installed in the ceiling of a space, and then the air pump inside of this detector is drawing air back to it where inside the centralized detector, we again have a detection chamber where we're measuring is there smoke coming back to this detector. What we get as an advantage is it's active detection now instead of passive detection because of the air pump moving air back to it; laser-based detection inside, fully supervised using airflow monitoring, and then end-to-end integrity monitoring. We can tell when a tube is cut, when it is pinched and not flowing, and did somebody cover up the sampling port. We can tell with the VESDA VEA.
And the last thing to note is that the VESDA VEA, inside of it has built-in, automated sample port cleaning. So on a frequent basis, it will increase the airflow to a port and suck back any dust, filter it out, so that we ensure that no sample ports have gotten gummed up from dust that might be in the space, and so some of those everyday applications that this might work for, I think a lot of the healthcare space. In hospitals, nursing homes, bed linens are changed frequently, and windows' linens are changed. There's a lot of lint that actually goes into the air, and that will often clog spot smoke detectors and cause them to be a problem, cause false alarms, cause more frequent trouble calls. Now, with the VESDA VEA, that will get to those sampling ports there, too, but that automated sample port cleaning will help deal with that lint in that type of space.
Inspection, testing & maintenance
Let's talk about inspection testing and maintenance of air sampling smoke detectors, and we'll start with inspections. Twice a year, the fire alarm code says to inspect your air sampling smoke detector. So some of the things you're supposed to look at are the sampling ports. Look at the piping in the system and the fittings, make sure everything is fit together and intact. Look for labeling and identification of the sampling ports in the space, and then look at the internal and external filters to verify that they are clean. On an annual basis, we need to test that detector. Remember, tests are active things that we do to test the detector. So the code says to follow the manufacturers' methods, but all the manufacturers basically say the same thing. They want to see an alarm response test through measuring the transport time, so they want us to go to the farthest away sample port and introduce smoke at that sample port, and they want to see that it registers at the detector.
Now, one of the new ways that we're doing that is with a benchmark test point for annual testing, and so the transport time test on an annual basis, introduce canned smoke at the end of the sampling port on each run, and time how long does it take to get back to the detector. Depending on the application, that will be either 120 seconds, maximum 90 or 60, but with a benchmark test point, the intent is for us, when we do initial acceptance testing, let's write down on a label next to that benchmark test point at the end of the system how long does it take for air to get back to the detector, and then every year when we test it, we look for about that same amount of time to get back to the detector.
The last thing that happens during annual testing, really is happening automatically, is the code says we need to verify airflow through all the ports. We inspect them visually twice a year, and then annually we just make sure that there are no airflow faults, but the airflow sensors that are part of air sampling detector technology just automatically make sure that we have enough airflow coming back to the detector.
Where can those test ports be located? This is a useful slide for teaching that. We want to try and have installations where the test port is accessible without having to get up to the ceiling, and so sometimes these detectors are on high ceiling spaces. Sometimes the sampling ports are above hard-to-access areas because of equipment, and so we want to run the end of the sampling pipe down to a level that it can be easily tested, usually within 6 feet of the floor, and for detectors that test below raised floor systems, subfloors and other concealed spaces, don't forget to run those pipes down to a sampling port that can be easily tested on that annual basis.
And then finally for maintenance for air sampling smoke detectors, detectors should have their filters cleaned on a yearly basis. Replace the internal filter modules every 2 years or as needed if it shows up dirty in the detector's fault codes. Any external filters and really dirty spaces that are applied, those need to be changed out every year or as needed. Then some other maintenance that we do is we often vacuum out the detector pipe networks every 2 years, or you can blow out those pipe networks with compressed air, but we find that vacuuming is really a great way to do that, and you disconnect the pipe at the detector, hook up a portable vacuum with a hose, run the vacuum for about 30 seconds, and then reconnect everything back up per each pipe.
We've had a great session here today. I know if you have questions, you make sure and put them through the chat, and we'll get an answer back to you. So thanks for listening about air sampling smoke detectors.
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