Episode Transcript
[00:00:00] Speaker A: Foreign.
Hi there. This is Amara Roskas and I'm with consulting specifying Engineer. Welcome to our podcast. Today we're talking about fire and life safety multi criteria detectors. And this is actually an offshoot of a really great webcast that we did in early April. And if you ever want to watch that webcast, listen to it, attend it for continuing education, you can go to cse mag.com webcasts plural/past. So that's cscmag.com webcasts past.
But to get to the point, today we're here to talk about multi criteria detectors. And we've got two really fantastic experts to talk to.
First off, we have Dave Lowery. He's Chief Fire Marshal with the City of Boulder Fire Rescue. How are you today, Dave?
[00:00:56] Speaker B: I'm doing great. I'm excited to be here, man. I really appreciate it. I just think it's awesome that we have enough interest in this subject that we get to come back and do a podcast.
[00:01:10] Speaker A: Fantastic. Thank you.
And Sean Mitchell, he's senior fire consultant with ARUP, based out of Boston.
Thank you so much for working with us here today.
[00:01:23] Speaker C: Well, thanks for having me again. I appreciate it. Looking forward to the follow up here.
[00:01:29] Speaker A: Excellent. Awesome. So we did have a lot of questions come in from the audience during this webcast and I just wanted to chat with the two of you. You've both got a lot of background, a lot of experience, and we're looking at this topic which is very complex. So multi criteria detectors are of course a complex topic within the fire protection industry.
And not only that, but there are so many things that people don't know. So I just wanted to jump right in and really ask both of you about best design practices.
What are some design practices in selecting locations in a building for placement of these multi criteria detectors?
[00:02:11] Speaker B: Well, I guess I can start with that.
So everything's in play when we're, you know, addressing detection and we're addressing the placement and the location. So all of our requirements and best practices and manufacturers requirements of where they can be and how they are mounted, all are in play. Right? I mean, so the manufacturer, what the manufacturer says basically goes, right, but you still have to take into effect, I mean, you know, the building itself, the compartmentalization of the building, the height, the ceiling construction, a slope ceiling, the environmental items that you're going to be dealing with in the, in the building, the airflow, the humidity, all of that still has to be taken into an account. Just like, just like a single detector, just like a, a smoke detector. All by itself or a heat detector, all by its itself. All that has to be taken into consideration.
The multi criteria, multi sensor detectors, they're no different, right? I mean, they're not, they don't stand out. They still have the same detection elements that, that we've, we've had in these other detectors. They're just combined all of a sudden.
[00:03:36] Speaker C: Absolutely.
And furthermore, I mean, you still have your ceiling type, your ceiling cavity, your beams, your beam pockets, all of those additional considerations to take into account when you're trying to place these lovely detectors that we're here to talk about further.
[00:03:55] Speaker A: Yeah, good point. Again, so complex, so difficult to think about all the things that we're bringing together here. So Dave, to kind of follow along with that, that question, why not space detectors at the smallest requirement for the combo detector, like heat versus smoke as an example, how does that all work?
[00:04:17] Speaker B: Well, you probably would, right? I mean, essentially you're going to, to space them with a detection element that's most conservative, basically. Or, or it has the smallest spacing. Right. You're not going to be allowed to over space one of the detection elements because the other detection element can go further. Right. So you are going to go kind of the most conservative detection element on there. And that's what the manufacturer will tell you as well.
[00:04:49] Speaker A: Okay, got it, got it. So are multi criteria detectors acceptable in residential dwellings then too? Or hospitality and kind of 120 vac smoke alarm be implemented or how does that all work?
[00:05:05] Speaker B: Yeah, I mean, multi criteria detectors, I mean, are. I mean, I think that's kind of the beauty of it. And I'll let Sean jump in on this one as well, because I think the way technology has evolved so much is that now I can, you know, once again, I can run down to the local hardware store and I can pick up a smoke alarm and a carbon monoxide alarm at that local hardware store. I can get a smoke alarm that has both a photoelectric and ionization detection element based on the type of fire that I can expect for my home. Right.
And those like the smoke alarm, the photoelectric and ionization are really probably more like a multi criteria.
Um, but then even that smoke alarm and the carbon monoxide alarm has the ability to give you two different signals, right? It has.
So you can distinctly hear a different tone for the smoke and a different tone for the carbon monoxide. Now by tone they're going to sound exactly alike. It's just going to be a different pattern that you're going to hear. So. Yeah, absolutely. The, that's what's fantastic about these is they are available for residential dwelling units now.
[00:06:33] Speaker C: Absolutely.
And I mean that's one of the things that NFPA is trying to get made aware to everybody out there is that they prefer that you do have that photo and that ion as one unit in all locations. In addition to those locations that require CO detection, like there's COS required on every level of your house.
And then with regards to hospitality.
Absolutely.
If you decide to have a 120 volt smoke alarm in lieu of addressable system type smokes or heats or combination devices that we're discussing, you definitely can use any one of these smoke alarms with photo and ion and co or heat and ion and smoke and co if it's available.
Keeping in mind that you'll need to match the manufacturer of every other alarm in the house because they all need to be interconnected and sound that temporal three or temporal four that they was just talking about with regards to that type of detection being used.
[00:07:58] Speaker A: So these are clearly the best things since sliced bread. Am I hearing that right?
[00:08:03] Speaker C: Absolutely.
[00:08:05] Speaker B: Yeah, they're pretty good.
[00:08:07] Speaker A: Good, good. So is there anything that a dumb detector does better than a multi criteria detector?
[00:08:14] Speaker C: I'll answer that one.
Yes, we talked about in the webinar, we talked about locations that these type of detectors, the multi criteria multi sensor detectors wouldn't be good at.
One instance I brought up was weatherproof locations. A dumb detector doesn't necessarily have the electronics inside the detector. So that temperature listing is gone. So I can be outside with a dumb heat detector at an elevator lobby.
So versus the multi sensor, multi criteria detectors which are addressable, which have electronics which are then required to be in a condition space per the manufacturer's UL listings.
[00:09:07] Speaker B: Yeah. And I can, I, I think I can add a little bit and I obviously agree with Sean 100 on that. I think, I don't think it's a fact of.
Well, let me say it this way. I, I think it really comes down to like, listen, you need to choose the best detector or detectors for the environment that you're going to be mounting them in.
[00:09:30] Speaker A: Right.
[00:09:31] Speaker B: And a multi criteria or multi sensor that may not, may not fit for everything.
[00:09:36] Speaker A: Right.
[00:09:36] Speaker B: I mean there is a, you know, a time and a place for everything. Right. And that's kind of what Sean was saying, that they're not, they're not meant to be mounted everywhere. They're not meant to be a hundred percent interchangeable with all of our detectors out there.
You have to, you have to look, you have to you know, look at your ceiling, look at your beams, look at the environmental conditions, look at all this and say what's going to work best and what's going to work based on the goal that I want that system to operate under.
[00:10:10] Speaker C: Right.
[00:10:11] Speaker B: And. And that's when the designer, I think, really has to make that decision.
[00:10:17] Speaker C: Absolutely, I agree 1,000%. And furthermore, we're not here to say you should never use a standalone smoke detector or smoke alarm ever again.
There are a ton of instances where you would still use a smoke alternative single station smoke alarm or a smoke detector in the residential or office type environment or hospitality for this instance.
But there are definite advantages of using that multi sensor detector, multi criteria detectors that we talked about.
If you'd like, go back to the webinar re listen and hear what we had talked about for those locations.
[00:11:04] Speaker A: Yeah, thanks Sean, for that clarification. And I have another question. This is another clarification question. You're talking about multi sensor and multi criteria detectors.
Are they interchangeable? Are they used for different things?
[00:11:18] Speaker C: How does what's up there definitely used for different things. Back in that webinar we keep referring back to NFPA 72 was referenced. And in that reference there's a chart specifically from an IPA 72 that distinguishes a multi sensor versus multi criteria. Multi criteria is a single standalone smoke alarm signal back at the fire alarm panel where multi sensor can be smoke, heat, co but it's the sensor is dependent upon the type of sensor you're using in your detector.
The multi criteria is where we're trying to distinguish photo uvir co any one of those to distinguish that specific smoke and verification back with those special algorithms that each manufacturer has to determine is it really an alarm event or is it, you know, I burned popcorn again and we don't want to dump the building.
[00:12:38] Speaker A: No, no jiffy pop emergencies.
So yeah, I think I got it, Sean. But is it the detection device or is it the panel that determines if it's multi criteria or multi sensor?
[00:12:53] Speaker C: It's actually the device.
So as an engineer, we specify multi criteria and multi sensor as two different devices.
However, that's what we show on the specs, that's what we show on the drawings.
Sometimes what gets installed in the field doesn't always match what you know. The intent was that ideally we pick up on things, however, at the panel, the fire alarm panel for that specific manufacturer of those multi criteria or multi sensor devices will be adjusted because they're not interchangeable.
It's programmed accordingly. But I'm not going to argue if you're using a multi sensor or multi criteria device where it could be interchangeable, but in a situation like we discussed before, where I have theatrical smoke from a fog machine, then I would say you're not going to use the multi sensor, you're going to use the multi criteria.
[00:14:08] Speaker A: All right, all right. Well, I'm going to switch gears here.
Dave, this question's kind of more for you.
What would be a good detector for exterior elevator lobbies to focus on that one particular instance?
[00:14:24] Speaker B: I think that was basically Sean's example on when a dumb detector would be appropriate.
[00:14:30] Speaker A: Right.
[00:14:31] Speaker B: So I mean, realistically, not a. Not a multi criteria, multi sensor, just a good old conventional heat detector is what you want to see in an exterior elevator lobby that's exposed to the, you know, the outside elements.
I don't, you know, there's three or four that can be chosen. I think a rate compensation is kind of like the better of the heat detectors, but that's just me. Sean, what do you think?
[00:15:06] Speaker C: Yeah, I would agree with that.
But at the same point in time, maybe we should define dumb.
You nailed it, Dave, when you just said conventional. I call it dumb. I'm sorry, I don't clarify.
I want everyone to understand that it's not a smart addressable system or a dumb, you know, fire alarm system. It's fire alarm system.
The fire alarm system, as long as it's addressable, can monitor addressable type devices. So in order to get a dumb detector, a conventional type device, you would have a monitor module inside that condition space, and then it would be wired back to your weatherproof heat detector location versus an addressable device. With those electronics, as I was bringing up earlier, those are required to be in a condition space per the manufacturer's UL listing. Usually it's 32 or 40 and up to 120 degrees.
[00:16:08] Speaker B: Yeah, I'm just more sensitive to the detector's feeling, Sean.
[00:16:14] Speaker C: Absolutely.
[00:16:17] Speaker A: Oh, okay.
Well, I think that we need to change gears again. If you're very sensitive about that one, Dave, we should definitely change gears.
What UL listing or other listing I should say, should we be looking at for smoke or heat detectors or hand stations? Like, how do those listings work?
[00:16:39] Speaker B: Well, here's kind of the textbook's answer, and I can let Sean kind of take over from this, but strangely, I don't often tell people this, but if you go to NFPA 72 and you go to chapter two, which is reference publications, and you go to that reference publications, and you look under the UL listings, you're Going to see a list of all these UL listings and on them they're going to say something to the Effect like a UL268, which is the UL listing for smoke detectors, to, to paraphrase, really what it is. So you can just.
That's what you would be looking for, right? I mean you also have like, you know, the residential smoke alarms listed in there, but all those. And you know, we could read all those numbers down, but they don't really. I mean they're already in print in NFPA 72. So rarely do we send people to chapter two. But there it is, right?
All of that information is right there in chapter two, giving you the UL and the title that you would be looking for for those detectors or other like horn strobes and, and manual pull boxes, things like that.
[00:17:53] Speaker C: The only other time we would talk about this is for our friends north of the border.
They have specific ULC listings and requirements that differentiate between smoke detectors, smoke alarms and heat detectors and CO detectors. But again, you'd have to go back to the ULC standards because I don't know those off top of my head.
[00:18:17] Speaker B: I'm sorry, I don't know the ULC either. And it's oddly, we don't actually list those in here even though it says it is supposed to be an international.
[00:18:26] Speaker C: Ideally it would, but unfortunately it doesn't. Yeah, but at the same point in time, if you talk to or review a manufacturer's data sheet, it should also list that specific ULC requirement as well.
[00:18:44] Speaker A: And by friends north of the border, you mean Canada?
Just to clarify.
[00:18:48] Speaker C: Yeah, them too, but yes.
[00:18:52] Speaker A: All right, got it.
Dave, kind of another clarification question for you. Would you recommend an MSD or an MCD for fire alarm detection? For gaseous fire suppression. Let's use a data center for an example.
[00:19:08] Speaker B: All right. Well, I typically don't recommend one thing over the other, but yeah, I mean for that, something like that, you would use a multi sensor detector. Right. Because you want. The panel has to receive those different distinct signals. Right. I think we talked about that in the webinar a little bit like, hey, you know, we used to like put you know, you know like four detectors in a, in a. You know what we use a data center room where you could probably only do one or two in there and we would cross zone them. Well now if we have different sensors that the panel can look at and see this sensor went into an alarm and now this other sensor went into an alarm for that gaseous suppression system to activate.
Yeah, I mean, I definitely think it's a, it's somewhat of a game changer that they, that multi sensor detectors can be used in a, a special suppression system like a gas system.
[00:20:17] Speaker C: I would agree with that 1,000%.
[00:20:21] Speaker A: All right, so speaking of gases, carbon monoxide. I know Dave is one of your biggest, most important things. If you're looking at a multi criteria detector, it has a single output. Can it be used for carbon monoxide?
Doesn't code require separate distinct alarms?
Can that be achieved? I mean, I know you talked about this, but how does that get achieved?
[00:20:46] Speaker B: Yeah, I mean it can and it does. And we did talk about it a little bit, kind of, you know, on, on a different question, but we kind of went to that. Right. I mean, yes, NFPA 72, Chapter 18 definitely requires distinct signaling. Right. And Sean had said it that for a fire alarm it's what we refer to as a temporal three pattern. And for the carbon monoxide alarm it's a temporal four. Right.
So once again it, you know, they sound the same. It's the pattern that is different that we're looking at. So in a simple multi criteria detector, like the ones that you would purchase for your home with a smoke and a carbon monoxide, when the smoke activates, it's going to beep three times.
When the carbon monoxide activates, it now will be four times. Right. It will have that different pattern.
Same thing. When we get into smoke detection and carbon monoxide detection, the panel can recognize that. And now. Well, the detector will recognize that, send that signal to the panel for that response to come out with either a temporal three or a temporal four. So yes, it very much fulfills that requirement and in giving those different signals.
[00:22:14] Speaker C: But be aware that the multi sensor detector is what we're referring to, multi criteria detector uses that CO to determine whether it's a smoke event that is an active event.
So you would be using multi sensor, not necessarily multi criteria, but at the same point in time, don't stop to count, the beeps get out.
[00:22:41] Speaker B: True.
But for the residential, is it, is it, is that considered a multi sensor?
[00:22:48] Speaker C: Yes. The smoke alarms with CO are dual listed for smoke and co. And so.
[00:22:56] Speaker B: Those are technically, even though they're not going back to a panel, they're just alarms. It still is a multi sensor detecting device.
[00:23:05] Speaker C: You got it.
[00:23:07] Speaker A: I set off my multi sensor detecting device every night when I cook. So I am very familiar with those temporal sounds. Thank you.
[00:23:18] Speaker B: You shouldn't be cooking.
[00:23:20] Speaker C: Well, I mean, yeah, I think I brought up the fact that My daughters have set it off a few times as well for cooking.
But I know our big thing with the false alarm activations in our house was steam because we had bathroom door in between two bedroom doors and you need a detector within five feet of either bedroom door.
So we had an ionization that kept tripping too often. So luckily I was coming up on the 10 year expiration for smoke alarms, so I replaced everything with photo cos.
So no more false activations at the bathroom and no more false activations with the dinner cooking.
[00:24:11] Speaker A: So, yeah, thank you.
Hopefully I will take away.
[00:24:15] Speaker C: Yes, hopefully in the future.
You know, these voice alarms that they're, you know, with this voice detection that they're coming out with, you can just say I'm making dinner and it'll turn off rather than having to, you know, wipe a bath towel around it to try and clear the smoke from it.
But I can only hope.
[00:24:37] Speaker A: Yes.
[00:24:38] Speaker C: And if somebody out there hasn't thought of it yet, you know, I, I don't mind trademarking anything real quick.
So.
[00:24:47] Speaker A: Good point, good point.
So, hey, Sean, you said the answer was it depends for half of the things that you responded to or talked about during the webcast.
So you cannot use. It depends on this one. Oh, sorry, sorry. Is it better to have a multi sensor or a multi criteria?
Multi sensor is probably better. Right.
[00:25:10] Speaker B: Well, let me answer it, Sean.
[00:25:12] Speaker C: Sure. Thanks.
[00:25:13] Speaker B: It depends. It depends.
[00:25:14] Speaker C: Thank you.
[00:25:15] Speaker B: Because she didn't say.
[00:25:16] Speaker C: I couldn't say it exactly.
Oh, yeah. I mean, again, I know we've touched on it before in the webinar. We've touched on it a little bit earlier here today, but in specific locations.
Like I keep coming back to that theater that I had in D.C. where it was, oh, you know, there's multiple theaters and it was general alarm and we're dumping the entire building the minute they set off the fog machine.
So drove us absolutely bonkers for about a week because, you know, play productions are wonderful, but they want to use the smoke during practice and whoops.
So in that instance, I would definitely not use the multi sensor. I would use the multi criteria. And that's what we went with. We were toying with the idea of providing bypass points and keeping somebody staffed in the fire command center to try and monitor the rest of the building.
But at the same point in time, having the multi criteria detector alleviated so many concerns because it was looking for that one smoke event, but testing with four different strategies to determine whether it is truly a smoke event that is, you know, from a fire or was it that theatrical smoke.
So we lucked out in that regards. But Dave, thanks for the assist. I appreciate it.
[00:26:54] Speaker B: Yeah. And it really just boils down to is, listen, you know, designing a fire alarm system is not one size fits all. I mean, every building is different and the fires that we see in them can react differently. And so it really does take someone that is qualified to look at that situation and design a fire alarm.
And just like, you know, Sean's example is a great, a great example actually to say, you know, there's some thought that has to go into this and, and, and using that. Right.
Initiating device is critical if you want to get that proper response.
[00:27:38] Speaker A: Very true. And I wish you could both see me shaking my head at you for your responses, but thank you. Thank you.
[00:27:43] Speaker B: I felt it.
[00:27:44] Speaker A: Yeah, you could.
I felt good. All right, so Sean, I'm going to ask you one last question here, and this is kind of wrapping it up, talking about testing and commissioning.
What are the best methods? How do you bring it all together and make it work at the end?
[00:28:00] Speaker C: Just like any other system type device, you're going to pull that pull station, you're going to blow smoke into that smoke detector. You're going to use that hair dryer.
If you couldn't tell I'm bald, so I don't have too many of those hair dryers, but there's specific ratings for the wattage, 1000 to 1500, I believe, to use to set off that thermal element. Inside that multi criteria detector there is canned CO that you can spray to get it. There is a manufacturer out there that has a one in one type device that will test them all.
You know, it'll use magnet to put it into test mode. That gives you a 10 minute window to sit there and test. It'll puff smoke, it'll puff co and it's got a heat element in it to set off the heat. The UV IR doesn't get specifically tested after the initial startup because that's being, that's using the algorithms that we keep talking about to try and discern whether the particles that are entering the chamber are large enough to be considered a smoke event.
[00:29:27] Speaker A: So I would recommend always going back to math. In other words, is that what you're getting at?
[00:29:32] Speaker C: Absolutely. I would recommend researching further based on whatever manufacturer that you're actually looking for, but keeping in mind that you still need to test all the elements possible.
So.
[00:29:49] Speaker A: All right, well, that is an excellent way to wrap things up. Thank you both so much.
[00:29:55] Speaker C: Amara, I've got a question for you.
[00:29:56] Speaker A: Oh, yes.
[00:29:58] Speaker C: Do you know why flames are so bright?
[00:30:02] Speaker A: No. Sean, why are flames so bright?
[00:30:05] Speaker C: Because fireworks.
[00:30:09] Speaker A: I did ask for a joke, didn't I?
[00:30:11] Speaker C: Yeah.
Sorry. Dad jokes. Yep.
[00:30:18] Speaker A: Well, Sean, thank you so much for the dad jokes. We've been speaking with Shawn Mitchell with ARUP out of Boston, and Dave Lowry with City of Boulder Fire Rescue in Boulder, Colorado. Thank you both so much for chatting with me today.
[00:30:35] Speaker C: You're welcome. Thanks, Dave. Thanks, Mario. Appreciate it.
[00:30:39] Speaker A: All right. Thank you for joining us. And we'll be back on the next COC Webcast. Bye. Bye.
