On the MeyerFire University side of things we've been getting into the fundamentals of hydraulic calculations and the basis for how we perform calculations today.
One of the concepts that I had not explored in any kind of detail was the Hazen-Williams formula itself - outside of perhaps a few hand calculations here or there when studying for a NICET or the PE Exam. It was developed early 20th center by Gardner Williams and Allen Hazen when they studied records of friction loss measurements from a range of experimenters. The formula they derived was empirical. For hydraulic calculations - it's been the staple our industry and the basis behind our systems today. I'd be particularly interested in diving a little deeper than we typically would to get a job done, and that might come in posts here in the next few weeks. How do we reduce pressure loss in our systems? What does the actual construction of the formula tell us about flow in our system? WHAT THE FORMULA SUGGESTS The exponents here are relevant - because of that 1.85 exponent - if we double our flow, then our pressure loss increases by 260%. If we triple our flow, then the pressure loss is 7.6 times the original! Exponents affect the C-Factor too. If our C-Factor improves from 100 to 120, our pressure loss drops 29%. What applications could that have for us? Well, if we install nitrogen on a new dry system - our C-Factor goes from 100 to 120. That could be a big deal on the right projects. What about diameter? With the 4.87 exponent, that has the biggest effect of all. If our diameter doubles, our pressure loss drops 97%! Even going from 2-inch to 2.5-inch drops pressure loss by about 60%! Of the variables in the Hazen-Williams equation, diameter has the greatest impact on friction loss. HYDRAULIC PARALYSIS We know that intuitively as pipe diameter is our first go-to for solving hydraulic issues and is also the one element we have the most control over as a designer. One concept not to gloss over, though, is the pipe schedule. Even seemingly minor differences in pipe schedule (thickness) can have a major effect on pressure loss considering that the effects of diameter have an exponential effect on pressure loss. If you're banging your head against a wall trying to round out a hydraulic calculation, make sure that all of your pipe diameters are optimized (of course), but also check that your pipe schedule is accurate. The difference between a Schedule 40 and Schedule 10 calculation over a long enough distance and a sensitive-enough portion of the calculation could have a big effect on pressure loss. Also - if you're ever stuck - try our tipsheet on ways to get out of a jam (Article #1 and Cheatsheet #2). In experimenting around with different values, I went ahead and put together a small calculator that does a Hazen Williams calculation with a few helpful lookup tables already included. If you don't see the tool below, click to check it out:
If you're well into your career, this might not present a whole lot of practical need - any sprinkler hydraulic calculation program already has this incorporated of course.
What I wanted to do is simply break out the calculation to explore the effects in a little more detail. Take the sample calculation, and tweak the inputs just a bit - you can do so by clicking on a dropdown, making any selection, then use the up/down arrows on your keyboard to flip through values quickly. YOUR TAKE What do you see that people often miss about the Hazen Williams formula? What, if anything, would you want to see on this tool as a means of learning about the fundamentals? I think it would be a little interesting to start a dialogue on the limits of Hazen Williams and potential range of accuracy (that is, actually explore it mathematically and possibly disprove some of the frustrating assumptions that tend to pop up regularly). What do you want to see? Water velocity? Limits? Comparison to Darcy-Weisbach? Let me know below. Hope to nerd out a little and see what we can come up with together.
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A couple weeks ago we updated the NFPA 13 shop drawing checklist with new references to the 2019 and 2022 Editions of NFPA 13. With the 2022 update, the NFPA 13 Committee revamped the list of requirements for “working drawings” in the 2022 Edition. It was pretty much gutted and rewritten. DOES A 2022 UPDATE CHANGE ANYTHING? What impact does this actually have for me or my team? Who uses the 2022 Edition right now? Well, perhaps no local jurisdictions have adopted the 2022 Edition yet. Perhaps that’s a few years away still. But what about US Federal work, which references the latest standard edition at the time of the job posting? Or large corporate or healthcare users who might mandate adherence to the latest codes & standards? Or, what if we’re just being prudent and looking to be ready to adapt when it is enforced? Well, yes then, it could have an impact on your process whether you’re creating the working drawings or reviewing them. Here’s the list of noteworthy changes to the working drawing list as I understand them. Please note that I’m far from a Committee member and it’s only my interpretation of the list. As this plays out in time, I’m sure plenty of gray areas will get sorted out in online discussions, informal clarifications, or code changes. The list of shop drawing requirements went through an entire revamp with the 2022 Edition. #1 SHOW THE MEANS OF FORWARD FLOW (ADDED IN 2019) A means of conducting a forward-flow test has long been required, but historically overlooked or was possibly achievable by flowing out of a fire department connection or main drain (for very low hazards). We talked about the big change for a fixed means of forward flow that was introduced in 2019 and clarified in 2022. How does this affect shop drawings? Well, we now need to locate and identify the means of forward flow on the plans [NFPA 13-2019 Section 27.1.3(25) and 2022 Section 28.1.3(18)]. The location and labeling of the means of forward flow is required in the 2019 and 2022 Editions of NFPA 13. #2 THE BUILDING CROSS-SECTION WAS REMOVED If you’ve ever prepared or seen a random building cross-section on shop drawings (with no pipe or sprinklers shown), that’s because NFPA 13 had a requirement showing a full-height cross section that showed ceiling construction, protection for non-metallic pipe, and structural member information. This was a constant source of review comments, which does help clarify what’s going on, but is only a single slice of a building that otherwise could be very complex. In the 2022 Edition, the list goes away from the building cross section and instead requires identification and locations of major structural members [2022 28.1.3(11)], labels of Obstructed or Unobstructed where applicable [2022 28.1.3(11)], and ceiling heights labeled on the plans [2016 23.1.3(45), 2019 27.1.3(5), and 2022 28.1.3(9)]. From a matter of design and practicality, showing ceiling heights and structural members on the plans themselves helps us all communicate a bit better. Showing all the ceiling heights, structure, and Obstructed vs. Unobstructed with plan labels was something I incorporated a few years ago and helped me be more disciplined during design. It also beats out a single-slice section of a building that may or may not actually clarify how much of the building is being constructed. A building section that doesn't detail sprinklers or pipe, nor is at a position or scale that effectively communicates the relationship of structure, ceilings, and coverage - doesn't do a lot of good. It may not have been the original intent of NFPA 13 anyway. The NFPA 13-2022 Edition removed the requirement for a whole-building cross section but added plenty of labels and requirements to the floor plans to adequately address the original reason for inclusion. #3 LIGHTS, DIFFUSERS, AND OTHER CEILING FIXTURES Many bid specifications require that lights, diffusers and other ceiling-mounted devices (fire alarm, occupancy sensors, etc) be shown on sprinkler working drawings. Doing so certainly helps prove that the ceilings have been coordinated – or at least other systems considered. But now that’s been codified. In the 2022 Edition, Section 28.1.3(8) requires diffusers, lights, and other ceiling fixtures or major MEP equipment just above or below the ceiling be shown on the sprinkler working plans. This seems easy enough to require for a consultant – but for a sprinkler contractor, pulling in this information can be a chore – especially if the sprinkler subcontractor doesn’t get a full set of CAD plans to begin with. Hopefully, with this being codified, a sprinkler contractor’s request for CAD backgrounds on this information gets a little easier to push back up the food chain. We know lights, diffusers, and other ceiling fixtures will be on a project. Now we're required to have them on sprinkler installation plans. #4 PLACARD INFORMATION Hydraulic Data Nameplate information has long been required to be shown on the working drawings, but now the hose demand, method of calculation, and total flow and pressure have been added to the list. This comes from the 2022 Edition, 28.1.3(23c). #5 OWNER’S CERTIFICATE INFORMATION NFPA 13 has long required that a signed Owner’s Certificate to be submitted with working drawings (1999 8-1.1.2, 2022 14.1.4, 2007-10 22.1.4, 2013-16 Section 23.1.4, 2019 Section 27.1.1.1(4), 2022 Section 28.1.4). Now, with the 2022 Edition, required information from the owner’s certificate is required to be shown on the plans [2022 28.1.3(14)]. This includes storage materials, storage heights, water supply information, and whether seismic bracing is required. This is discussed in more detail in 2022 Edition Section 4.2. The Owner's Information Certificate has been a requirement to be included with working drawings, but now the required information from it is also required to be shown on plans, starting with the 2022 Edition. #6 DESIGN CRITERIA FOR EACH SPACE The 2022 Edition clarifies that design criteria for each room or space be shown on the plans, including hazard classification everywhere, and commodity classification, storage type, configuration, height, and packaging for storage areas [2022 Section 28.1.3(15)]. That’s often critical yet hard-to-find information for plan review. This clarification puts some teeth to requiring that information be shown on plans. #7 FLEXIBLE DROP INFORMATION The 2022 Edition introduces requirements to indicate corresponding k-factor, length, manufacturer, maximum number of bends, minimum bend radius, and model for flexible drops when they’re used [2022 Section 28.1.3(17b)]. While many designers already indicated at least some of this, having the maximum number of bends and minimum bend radius on the plans could go a long way in helping on-site inspection make sure that the install actually adheres to the design intent. Not a terrible idea. #8 MORE SEISMIC DETAIL The 2022 Edition requires more detail on several seismic bracing components. These include design angle categories, flexible coupling locations, locations of seismic components, maximum spacing, penetration clearances, and zones of influence all to be shown on the plans [2022 Edition Section 28.1.3(22)]. IMPACT FOR PLAN REVIEWERS The “working drawing” revamp in the 2022 Edition shakes up an area of the code that hasn’t changed much in some time. For plan reviewers, this is a welcome relief. Many of the updates and additions are simply requiring pockets of information that a plan reviewer needs to know for proper review, but is really difficult to surmise if they’re outside of the design development process. Having teeth to require that commodities and storage arrangements and Obstructed & Unobstructed be identified on the plan will go a long way in checking due diligence has been done in key areas. IMPACT TO DESIGNERS For designers? This could be a tall ask. There’s some major adjustment here. For designers who traditionally have been very thorough in plan preparation and documenting each step of the process, this will be more of a matter of simply sharing some of that documentation. For designers that may not have gone into this level of depth – there’s certainly going to need to be more time dedicated to the process. More time to ask the owner for input. More time to ask for more complete backgrounds for coordination. More time to document, label, and identify details on plans. It’ll take more time. If designers already feel crunched by design time budgets, then it’ll be be an adjustment for everyone. IMPACT TO ESTIMATORS For estimators? When the 2022 Edition (or later) gets enforced, plan on designers needing some additional time to take this on. Time adds for design will be greatest for buildings with storage, seismic projects, or jurisdictions who provide thorough review. There’s plenty of teeth to the the updated list, so it’s less of a “well these things are technically supposed to be provided in the spec” and instead “NFPA 13 requires this to be shown.” Less room to maneuver, in other words. TAKEAWAYS Personally, I like these changes. They allow for clearer communication of intent, which is the point of drawings in the first place. It’ll allow designers to be more thorough in their process. While that might sound contradictory (why would a designer want to be pushed to be more thorough?), many good designers lament that the pace and expectation for flying through design is too fast. Having NFPA 13 be the backbone of what needs to be submitted gives designers a tangible justification to do a more thorough (better) job. The NFPA 13 requirements can play the part of the villian, not the designer who’s trying to do things at a depth that they feel is needed. Hope you enjoyed the recap here, and that you have a great rest of your week. Keep up the good work. - Joe Last week we updated the NFPA 13 shop drawing checklist with references to NFPA 13 2019 and 2022 Editions. While code updates like this are traditionally modest, the NFPA 13 Committee revamped the entire list of requirements for “working drawings” in the 2022 Edition. It was gutted. We’ll expand on that more next week. This week I’d like to key in on one very impactful change that I think will affect many of us in how we design systems going forward. FORWARD-FLOW REQUIREMENT HISTORY A forward-flow test has long been required in NFPA 25 (dating back to at least 2002). The purpose of the test is to verify that a backflow preventer is capable of fully-opening in a fire – or at least to the extent that it allows enough water to flow to satisfy the sprinkler system’s demand. A means of conducting a forward-flow test has long been required, but not necessarily readily implemented. For many lower-hazard systems, it was a test that was possible by flowing out of a fire department connection or main drain. WHY NOT FLOW OUT THE FDC? White it was possible to do a forward flow through an FDC, this approach was never practical. I can’t stand on a high horse here – it was the approach I long used from a design perspective. It’s not practical because conducting a forward-flow test out of an FDC would typically require a system to be shut off, drained, check valve reversed, put back into service, tested, shut off, drained, check valve put back into place, and put back into service. And that was if the clappers on the FDC were removed or restrained in a way to allow enough water to pass through. It’s a tall ask. USE THE MAIN DRAIN? Flowing out the main drain could be a solution for forward flow, but practically speaking how much water can flow through a 2-inch main drain, especially if there’s an OH1 or OH2 demand? Do we have a way to verify how much water we’re flowing, so that we know the test passed? Some have used our own calculator to estimate the amount of water flowing through a main drain by using this orifice flow calculator - https://www.meyerfire.com/blog/a-new-fire-sprinkler-test-drain-flow-calculator That calculation is based on pressure flowing through an opening – either an orifice or pipe diameter – and doesn’t incorporate the losses that occur through the length of a main drain or the fittings along the way. It’s going to be too generous on the amount of flow coming through a main drain – which is good if we’re wanting to know how much water a plumbing drain needs to accept – but bad if we’re trying to prove forward flow based on it. I would suspect that a supply-side calculation (where the available pressure dictates the flow) through a fully-open main drain would be the best way to predict hydraulically how much flow a main drain could flow. If that’s well above the system demand (including hose allowance), then a main drain could be the means to flow. But a 2-inch main drain is very likely not an answer for forward flow for most systems. I’ll leave that discussion open – perhaps there’s a tool we could construct to account for main drain losses and perform that supply-side calculation. PERMANENT MEANS FOR FORWARD-FLOW Somewhat fortunately for those of us who like black and white guidance (myself included) –the NFPA 13 committee closed up the gray area in the 2019 Edition by requiring that an arrangement for conducting the forward flow test, at the minimum flow rate of the system demand (including hose allowance), would be provided “without requiring the owner to modify the system to perform the test.” This comes from NFPA 13-2019 Section 16.14.5.1.1. In the 2022 Edition, the committee went further. A fixed means of forward flow, like hose valves on a test header or system riser, will become far more commonplace once the 2019 and 2022 Editions of NFPA 13 are adopted and enforced. A 2-1/2” HOSE CONNECTION FOR EVERY 250 GPM A test connection is now required for forward flow tests, where now a 2-1/2” hose valve is required for every 250 gpm (950 L/min) of system demand. This total flow must include the hose allowance where applicable. Generally, if there are interior hose valves, then this would need to get added in. So - an Ordinary Hazard Group I system that may have a demand of 270 gpm (with 250 gpm outside hose allowance), would still need two 2-1/2” hose valves for the forward flow test fixed in place downstream of the backflow preventer. For larger systems, or those with interior hose connections? We could be looking at three or more hose connections just for forward flow. This comes from NFPA 13-2022 Section 16.14.5.1.1. That’s a noteworthy change. For a code-minimum, sprinkler-system-only type of project, that’s a tangibly different cost and look to a part of the system. Does this have to be a test header on the outside of the building? Not necessarily, though that would be nice for future testing. Could the hose valves be on a riser in a room that has exterior access? Depending on the room and goals for the building – that could be reasonable. There are two provisional sections that allow existing hose connections to be used for the test (16.14.5.1.2), and other means to test are allowed “as long as the system doesn’t require modification to perform the test and is sized to meet the system demand.” The later comes from NFPA 13-2022 16.14.5.1.3. Is a fixed test-header on the exterior of the building required? No, but it could be convenient for future testing in areas where theft is less of a concern. HAVING TEETH
But in general – we don’t have a “use the FDC” workaround any longer. For those in IT&M, we finally have a sticking point to give an ability to do this test without tinkering with the system. For those in design, we finally have a magic section of code that we can show to justify providing a means of the forward flow test. For those in review and inspection, we have the teeth to enforce it. Hopefully, in the long-run, having systems tested for forward flow will identify backflow preventers aren’t functioning and we no longer have them in buildings ready to fail when a fire happens. Hopefully, this pushes buildings to a bit safer and helps us a be a little more confident in the system’s ability to fight a fire. SHOW ON WORKING DRAWINGS While the means is an installation question – NFPA 13-2022 Section 28.1.3(18) requires that working drawings locate and identify the means of forward flow. It’s no longer a “how do you plan to do this test?” type of comment and will soon be “show the location and label the means of forward flow, per 28.1.3(18).” MY FORWARD-FLOW STORY Are we really just testing the backflow preventer here? Well, yes. In part. But actually flowing an entire system demand tells us quite a bit. It means that our water supply is capable of flowing the full system demand, and all the pipe in-between the water supply and the backflow is also open-enough to flow the full system demand. I once had a project where a tap was made to the city supply main. It was a live tap or “hot tap,” where a drill punctured the side of the city main and a new 6” street valve was installed and our 6” underground came in and fed the building. It was a brand-new 3-story building that was going to have overnight guests. The tap wasn’t fully-made. In fact, as we found out later through a lot of cost and trouble, only a ¾” pilot drill bit made it through the city main. It wasn’t all the way drilled-in. Instead of a 6” tap, we had a ¾” tap. Static pressure to the building was fine. We could run a main drain test just fine (the residual dropped, but the main drain isn’t flowing all that much). Remember – the initial main drain test sets the threshold to check against in the future. We could flow the inspector’s test just fine. When we conducted the forward flow test and opened a couple 2-1/2” hoses – we had no water. No pressure at all. It wasn’t until we conducted the Forward Flow test that we knew there was a problem. Where it not for the Forward Flow test, we would have had a brand-new building, which, by all other measures we would have thought was designed and installed properly – all protected by a system with water that was squeezed through a ¾” hole. While the backstory of testing the Forward Flow may be more about the backflow preventer, the test does give us confidence in the supply up through the backflow preventer being able to handle the system demand. If we measure the flow coming from the forward flow, and also stick calibrated gauges on the upstream cock and downstream cock of the backflow – we can know a whole lot about the health of our system that day. What’s the static pressure? What’s the loss through the backflow? What’s the base of riser pressure at the system demand? How does that compare to our design? We can get a lot of information just from this one test. END SOAPBOX That’s my soapbox rant for today. As with all we write and do on this site, I hope you’ve found it helpful. Keep fighting the good fight, and have a great rest of your week. - Joe Have you had a project with an overhang that needed sprinkler protection and extended just beyond the throw of a dry sidewall sprinkler? It’s a smooth, flat or nearly-flat overhang that’s, say, 21’-6” wide, and in an environment that will dip below 40 degrees F at some point. What are your options then? OPTIONS All of the extended coverage dry sprinklers we know on the market cap out at 20’-0” horizontal throw. That would have been our best option. We could look at using a dry system. There’s the additional cost of the valve, slope requirements, a hit on the remote area size, more corrosion potential – and on and on. It’s costly. We could look at an anti-freeze system. Those come with more restrictions than they used to, but at a minimum would involve an RPZ and now pre-mixed antifreeze solution. Additional cost. Heat trace the pipe? That’s problematic, at best. It needs to function 100% of the time that it’s needed, or pipe will freeze. It needs to be supervised. It needs to be maintained. And when in conjunction with pipe insulation it looks terrible. In short, an overhang that’s just beyond the reach of a dry sidewall sprinkler can take us to a whole new cost tier in the design of a sprinkler system. CODE-COMPLIANT CREATIVITY We had just this situation on a project a few weeks ago, and tried to think creatively to get a code-compliant solution that’s best for the owner, yet doesn’t spike the cost for a dry sprinkler system that only serves four sprinklers. Now normally, sprinkler design tends to be a one way street. An architect designs a building. It gets bid and handed down to the sprinkler contractor. The sprinkler contractor “makes it work” with what they’ve been given. If a consultant is on-board, this would be a great opportunity to pick off challenges like this and advice the architect and owner on ways to mitigate this cost spike for a small project. Perhaps the overhang is designed at 19’-6” instead of 21’-6”. Perhaps they build it with all non-combustible materials if it otherwise didn’t have storage below. Those could be helpful changes that reduce the overall cost in a major way, but may not be a major detriment to the owner’s goals for the building. #1 SHORTEN THE OVERHANG Regardless, we suggested that the width of the overhang be actually shortened to allow a sidewall’s throw to cover the distance and prevent the need for a whole dry system. That didn’t go anywhere. #2 EXTEND THE REACH OF A DRY SIDEWALL We then asked if a soffit could be built to allow a sidewall it’s spacing of no more than 20’-0”. The soffit wouldn’t have to be heated. It could simply be framed (hopefully of non-combustible studs) with sheetrock or a “Hardie Board” or some other skin. It could be almost completely empty on the inside. The goal would be to give a dry sidewall sprinkler a back to collect heat and be installed properly. KEY RULES There’s a few notable rules that come into play here, though.
So working backwards, a soffit that is say, 2’-0” wide and 2’-0” tall would allow a dry sidewall sprinkler to:
But then, we need coverage below the soffit too, right? This could be accomplished with a flexible dry pendent, such as the V3517 dry flexible pendent sprinkler. Just like the dry sidewall, the flexible dry pendent could contain water back on the warm interior space. DIGGING DEEPER We also would want to offset these locations on plan, so a pendent isn’t immediately under a dry sidewall. Offsetting the locations in plan could help potential cold-soldering concerns. We’d also want to be sure that both the dry sidewall and the dry flex pendent would be able to be replaced at some point in the near future. NFPA 25 used to require sample testing or replacement every 10 years starting at 10 years after installation, but the 2020 edition bumped that starting point up to 15 years and the 2023 Edition bumped it again to 20 years after installation (NFPA 25 2017-20 Section 5.3.1.1.1.6, 2023 Section 5.3.1.1.1.5). To accommodate replacement and testing, we might need a way to get access to the inside and the soffit in the future (access panels or future cutout). COST & CONSEQUENCE After all this effort – will the soffit cost more? Sure. Would it cost as much as a dry or anti-freeze system? No, it shouldn’t. Does it help with corrosion and IT&M in the future, considering we wouldn’t have a dry valve and an additional nitrogen system or air compressor? Yes, that’d help too. Just an idea that might help address those “in-between” situations that could spike cost for a smaller-sized project that otherwise wouldn’t need it. What are your thoughts? Have you tried this before? What tips would you suggest? Hope you’ve found this interesting and perhaps moderately helpful, and I hope you have a great rest of your week! Until I did some research recently, I hadn’t realized that NFPA 72 breaks out different definitions for Unwanted Alarms by fire alarm systems. In a way, as an FPE I always kind of shuttered and turned a blind eye to the reality of how much of the rest of the world views fire alarm systems – as a nuisance. Imagine yourself flipping through a book that you’ve pulled off the shelf at the library. It’s quiet; the librarian shushers are about and keeping the noise down. Then suddenly the fire alarm system activates – it’s loud, startling, What is the first thing that comes to mind when this happens? As a fire person, I jump into detective investigator mode. I understand what kind of inputs would trigger an alarm, so I’m naturally very curious on what might have happened. But what about the ‘Average Joe?’ If it’s a calm library on a quiet afternoon, are they in a rush to leave? Or is their first thought “it’s probably a false alarm?” I can tell you by experience that unless there is another signal, like the smell of smoke, sight of smoke, or others moving quickly – most will pay attention and mostly ignore the alarm. They assume it’s a false alarm until they have evidence that suggests otherwise. FALSE ALARMS DON'T REFLECT WELL This is really bad for our industry. The prevalence of false (unwanted) alarms makes people apathetic to the alarm in the first place, and it reflects poorly on us. Is the reduction of false alarms more important than detecting an actual fire event? Of course not. We need these systems to detect and alert us that something is up. But as a downstream effect or a lesser-priority, we also should pay attention to finding ways to reduce unwanted alarms. We want our systems to be trusted and we want people to react when they someday do activate. WE JUST TALKING IT&M? Much can be said about regular inspection, testing, and maintenance of the system. Old and dirty smoke detectors can certainly cause alarm when there isn’t a hazardous condition. But from the very beginning, we can help prevent unwanted alarms by design. That’s something that designers, engineers, plan reviewers and inspectors can help prevent from the very beginning. BRAINSTORMING IDEAS I don’t have all the answers here, but I would like to start the dialogue and open discussion on clever ideas that help reduce unwanted alarm. NFPA 72 has a list of terms that fall under Unwanted Alarm, which is any alarm that is not the result of a potentially hazardous condition. It lists Malicious Alarm (person acting will ill-intent), Nuisance Alarm (alarm by a non-hazardous condition), Unintentional Alarm (person triggers but by accident), and Unknown (no known cause). My gut says that Malicious and Nuisance are the most preventable. How can we discourage someone from activating an alarm as a prank (Malicious), and how can we reduce Nuisance Alarms where there is no actual threat? Here is my shortlist – I am very interested in your tips and takes on additional ideas to avoid Unwanted Alarms by design. #1 REMOVE MANUAL PULL STATIONS (WHERE ALLOWED) The most-accessible method for an occupant to activate a fire alarm system is with a manual pull station. The IBC (most commonly-adopted model code in the US) has exceptions to remove manual pull stations for fully-sprinklered buildings. When this exception is offered, it’s worth considering. Many new construction projects require fully-sprinklered buildings anyways, so eliminating the exposure for a pull station in a highly populated area would reduce the potential for pranks. That being said, always consider the alternative. Are we talking about a middle or high school situation, or a hospital? Is it a dormitory, which is all-but-guaranteed to have a 2am alarm activation during Finals week? Or is it a critical care facility where there are multiple patients who cannot self evacuate? Manual Pull Stations do have their purpose and place in the industry; so we still want to consider the context and purpose for them. One important note that’s often missed – using the exception to remove manual pull stations doesn’t remove all of them in a building. One pull station must still be installed “at an approved location,” just not at all exits. #2 USE DUAL-ACTION PULL STATIONS If we can’t, or don’t want, to eliminate manual pull stations at all exits – then let’s think about securing them. Can we make the pull stations a little more involved to activate? Would going from a single-action (just pull down) to dual-action (push in and pull down) help prevent accidental activations? It’s possible, though I personally haven’t seen data to suggest it. I can’t imagine a teenager being discouraged by a minor additional action if they already plan to activate a system. But could it prevent a tall and curious five year old from activating the system? Possibly. Going from single-action to dual-action isn’t a notable cost difference, so this would be fairly easy to execute. If you have data on this – be sure to chime in in the comments. #3 PIEZO COVER FOR MANUAL PULL STATIONS Now “Prank” isn’t a formal term here, or at least not yet. But many of my personal experiences with false alarms was during college in the dormitories. How can we make activating a pull station troublesome for someone who is actively looking to empty a 1,000-person dormitory as a “prank”? One way is to put covers with a piezo alarm on the pull station itself. The piezo buzzes as soon as the cover is lifted, which draws attention to the location. If someone is activating the system during an actual fire, the logic is that they shouldn’t be deterred by a buzzer. But someone who’s trying to “get away” with something? Maybe the attention is a deterrent. Can using a Lift Cover with local Piezo alarm discourage malicious alarms? #4 VIDEO MONITOR PULL STATIONS AT EXITS Perhaps a better long-term solution isn’t a buzzer but a security camera at the location. If exits are already being monitored for security in that area, why not get a camera placed to include the pull station? If it’s much harder to avoid discipline, perhaps the security camera acts as a deterrent. While this might sound expensive – just imagine how many malicious alarms happen in some occupancies? The cost, time and effort of fire departments responding to calls that should have never been placed in the first place? It’s extremely disruptive and very well could lead to fines too. Addressing some of this upfront, when the building is being designed or renovated, could have lasting financial benefit to the owner. #5 SIGNAGE AT MANUAL PULL STATIONS Along the line of logic for security cameras – what about the threat of security cameras? Even just basic and clear signage right above the pull station of “SMILE, YOU’RE ON CAMERA” would be an inexpensive but potentially effective way of deterring bad players. Having a reminder for consequences may just be as effective even if a camera is not actively recording. If you’re a graduate student and looking for a research paper – maybe test this out and let us know. #6 SMOKE DETECTOR LOCATION Thus far we’ve focused on manual pull stations, and that’s because they’re the most easily-recognized way for anyone to activate the system. But what about the nuisance alarm? Perhaps the most front-of-mind false alarm is burned popcorn activating a nearby smoke alarm. Why is that smoke alarm there in the first place? Can locating required floor-level smoke alarms further away from cooking appliances help prevent nuisance alarms? Well, typically in homes, smoke alarms are required within sleeping areas, just outside of sleeping areas, and on each floor level. Similar requirements are found for residential occupancies. The IBC is explicit in the areas that need smoke detectors or smoke alarms in Section 907.2.
If a smoke detector is required in the area, how can we improve the situation? Can we shift the location to be as far-away from cooking sources as possible, but still be along the path of egress that we’re seeking to satisfy the IBC and NFPA 72? Many times it seems that during design, the smoke detector is just a hex with an “S” on it. It’s just a symbol that gets popped wherever there’s blank space on the CAD plan (I’m guilty of this). We need to be better than that. If a smoke alarm or smoke detector is anywhere near cooking appliances (stoves, microwaves, ovens) – then let’s get those detectors further away but still meet code. That extra distance means that normal cooking exhaust is going to diffuse and be less likely to trigger the smoke alarm. Here again – think about context, what we’re monitoring, and what we’re trying to achieve with the detection in the area. #7 USE THE UL 268 7TH EDITION One of my favorite improvements concerning smoke detection is that the UL 268 Standard for Smoke Detectors for Fire Alarm Systems, recently added a specific test, informally called the “Hamburger Test,” that requires a smoke detector or smoke alarm to not activate under specific cooking conditions. On a side note, the 7th Edition also includes a test for correctly responding to burning foam, which better matches modern furniture padding material. These additional requirements have come into play with the 7th Edition, which is now mandated for newly manufactured smoke alarm and smoke detectors. This is a huge step in the right direction to trigger less nuisance alarms. If we have the opportunity to install or specify UL 268 7th Edition detectors, that might be a major value-add for the owner. I don’t know the current status of availability or whether the manufacturers have caught up to the requirement yet, but the 7th Edition of the standard is currently mandated for new devices. YOUR EXPERIENCE What tips do you have? What are some practical considerations you make when designing or reviewing fire alarm systems? If you’re an AHJ, consider kindly advising owners or designers to consider these things by passing along the “lessons learned” can have a tremendous value to the owner. They can say no where it’s not code-required, but having been in the consulting space I’m incredibly appreciative of tips to consider that is in the interest of the owner. Comment below with your tips or ideas that you like. As always, thanks for being part of the community here! How do we solve the systematic problem we have with fire protection bid documents? Some, if not much of the plans and specifications that go out for bid are generally helpful. A quality set of fire protection bid documents:
These types of bid sets do happen. But far, far too often, they don’t. It’s systematic, and makes every step of the design and installation process far more difficult and far more costly than it could be. NOT FAULTLESS I don’t even want to pretend I’m not at fault here. I’ve designed poor projects. I’ve slacked on coordination, and detailing. I’ve glossed over parts of a project that I shouldn’t have glossed over. It’s been painful. But this is something that we can change. WHAT CONTRACTORS SAY For some years now I’ve spoken with sprinkler contractors, architects, and consultants about this. If you’re a contractor, especially if you work in estimating - you could provide countless examples of terrible bid documents. Bid documents that actually get in the way of you doing code-compliant, efficient work. You could speak to this far better than I can. In these conversations, over and over, I’ve heard one key feature that I think many consultants in the MEP space miss. It is far better to have no fire protection bid documents, than to have bad fire protection bid documents. NO FIRE PROTECTION BID DOCUMENTS? That’s important, and counterintuitive. It is far easier for a sprinkler contractor to look at a project and define their own scope, and put a price to it, than it is to try and bid a set of documents that:
If that sounds too far, ask your closest estimator friend. They see this all the time. How many projects do we see underground feeds piped 20-ft before rising up? How many times do we see Star, Central, or Gem still specified today, in 2024? How many times do we see projects wanting a fixed-price bid yet have zero information about the water supply? How are those documents helpful to a bidder? They’re not. MY ANALOGY The analogy that I’ve had in my head and finally am able to bring to life a little is the road, showing the different tiers of fire protection bid documents: 1 - NO FIRE PROTECTION BID DOCUMENTS
There’s the sidewalk on the left, where we have no fire protection bid documents. Let’s say we have a single-family home with an NFPA 13D system. Scope is simple, perhaps we have no specific owner needs, and it’s unambiguous. That type of project probably warrants no upfront, pre-bid fire protection involvement. It wouldn’t have to just be a single-family home though. What about an add & relocate job for a small retail space. Or a small office building. Those can, and often do, work just fine without any upfront fire protection bid documentation. Design-build all the way. 2 - QUALITY "PERFORMANCE SPECIFICATIONS" Then we skip ahead to quality “performance specification” documents. These do all the things we’ve talked about. They don’t necessarily show pipe or sprinklers, but they clearly define the scope, they communicate clearly, they answer major scope questions, they address and alleviate major issues or coordination challenges upfront, and they make it easy to put a price to the job. That’s a quality set of “performance specifications”. 3 - QUALITY "FULL-DESIGN" For high-end jobs, or high-hazard jobs, or critical function or high-visibility or unique jobs – perhaps we’re looking at a full-upfront design prior to bid. Full-design isn’t free, nor quick, and isn’t necessarily the answer for every job. But, as we’ve talked on this topic before; if it’s done well, and thoroughly, then fully-detailed plans can be a tremendous asset to a project. They can eliminate ambiguity and really dial-in exactly what work needs to be done. AND... THE DANGER ZONE What about the DANGER ZONE? There’s a gap, and it’s in-between no bid documents and quality “performance specifications”. And that is the Danger Zone. This is the lane of bad bid documents. These are all the bad things. Inconsistent, boilerplate, confusing, inaccurate, unachievable, irrelevant, or not actually code-compliant. What happens when we live in that lane? We get hit by the proverbial bus. Change orders. Litigation. Or much worse – a fire happens with major loss. This is not the spot to be. WHY DO WE STAY IN THE DANGER ZONE? I’m fairly confident that those who live in that space don’t want to be there either. They feel compelled because the client asks for fire to be included. They feel pressure because competitors are offering to do fire protection. They feel they can’t spend enough time on fire because there is hardly any fee there. Honestly – these are all poor excuses. If there isn’t enough money in the job to put together a quality set of fire protection bid documents – then don’t do them at all. It is far better to have no fire protection bid documents, than to have bad fire protection bid documents. HALF-BAKED DOESN'T HELP Bad, sloppy, half-baked documents don’t help. They don’t solve anything. They get in the way. If you’re the MEP who finds yourself in this area, having that conversation with an owner or architect and there’s just not enough fee to do quality work – then just exclude it entirely. If an architect insists that it get thrown in or done on a microscopic budget, then just ask them to hire a fire protection consultant separately. Half-baking a set of documents is not worth the hassle or the liability. It also doesn’t actually help. When you do take it on, do it well. We all benefit from that. YOUR TAKE If you’re a sprinkler contractor or architect – I really want to hear from you. Where do you land on this? When projects have gone south or had major change orders – what happened? Would being in a different tier have changed the result? Comment below, would love to hear your take. And, thanks, as always, for reading and being a part of the community here. We will get this right. The majority of bid documents for fire sprinkler work is some form of delegated design. A consulting engineer frequently does not provide all of the detail about a system (pipe locations, size, hanging methods, hydraulic calculations, etc). Why is that? In other disciplines, the opposite is common. Mechanical Engineers regularly selects a system type and lays out ductwork in a one-line or two-line configuration on a plan before a contractor bids the system. Electrical Engineers commonly size up, calculate and provide power and lighting locations on plan with an overall one-line diagram. Even plumbing often has plans for domestic water feeds and sanitary waste. Why doesn’t that happen for fire protection? First, the biggest disclaimer today, I’m not advocating for all design to be upfront. Or even a majority of it. I do see many applications where a quality FPE consultant can provide a tremendous amount of value to a project. I explored this a bit with The Delegated Design Problem and in A Practical Design Spec Checklist. But I would like to start the conversation and get your ideas on why we are where we are today with why designs are not done upfront. Here is why I think all sprinkler design is not completed upfront, before bid time. #1 WE DON’T WANT EVERYTHING UPFRONT
Overwhelmingly, the sentiment I hear from sprinkler contractors about ‘full-design’ fire sprinkler drawings is that they wouldn’t want upfront designs for all projects. Why? Because in some (or many) cases, sprinkler contractors feel that upfront design either limits their flexibility or is of very poor quality, or both. A design that doesn’t coordinate with other systems, or ‘leaves coordination’ for the sprinkler contractor, is problematic. It’s difficult to bid and difficult to work with after a project has been awarded. How much needs to be ‘coordinated later’? How ‘real’ is the design? Is it less efficient than the contractor could have laid it out? Many who have designed on the contracting side feel that real-world “fit” and doing the sprinkler layout are one in the same. You can’t ‘rough-in’ a layout without thinking about conflicts and making it actually work in the real world. As an extreme example, I think most could agree that a basic NFPA 13D layout does not need upfront involvement by a consultant. Could they help? Perhaps. Could they provide value? Perhaps. But it does not need a high level of involvement. Now there’s a big counterpoint to this. Just because we don’t want upfront design on all projects doesn’t mean it wouldn’t be beneficial on some projects. Projects that have very specific needs, unique needs, high-visibility challenges, coordination challenges, or that require a specialized set of expertise could very much benefit from upfront involvement. Maybe it’s a retrofit in a high profile historic museum. Maybe it’s suppression for an automated storage retrieval system. Maybe it’s a unique storage configuration that is outside the bounds of NFPA 13. In these types of situations, involvement from a quality FPE consultant can address code concerns and clearly define the scope. It can help mitigate a lot of risk for contractors by doing so and help everyone bid apples-to-apples instead of a wide-open, ill-defined scope. #2 INADEQUATE WORKFORCE (INDIVIDUALS AND COMPANIES) Perhaps the alternative reason is the lack of expertise in the workforce. We simply don’t have enough people, nor expertise, to take on every project. Even if we wanted upfront involvement to a high-level of detail, we as an industry couldn’t pull it off. We don’t have enough bodies, nor enough qualified expertise. Is it an issue? Absolutely. Does the lack of people affect how well we advocate for fire protection itself? Absolutely. Could the construction experience for architects and owners and contractors actually benefit from more and better individuals working upfront on project? Absolutely. But until we catch up on the quantity of our own workforce, we simply can’t take on more involved work. #3 LOCATION OF THE EXPERTISE Another reason we don’t perform highly-detailed layout work upfront is the location of where expertise for layout technicians often falls – and that’s in contracting. Anecdotally I know far more layout technicians in contracting than I do in consulting. In our survey of nearly 500 industry professionals in 2022, of those who had roles as a designer or layout technician, 68% of them worked for contractors (another 4% were self-employed). That’s different than other disciplines where there is plenty of design and layout expertise embedded in consulting. #4 DOWNSIDES: COST, INFLEXIBILITY, & SCHEDULE Involving expertise upfront isn’t free. There’s a cost associated with it. We mentioned it before and stipulating a full layout upfront also set some parameters in place that can limit the creativity and efficiency of a contractor-provided layout. Lastly, there’s time needed to do that work upfront. Having a high-degree of involvement may not be a positive impact to overall project schedule. SO CAN WE KILL-OFF UPFRONT INVOLVEMENT? It sure feels like I’ve put out a hit piece on any upfront involvement in fire sprinkler design. The question is – does all design need to be done upfront? By an engineer or consultant, or someone other than a contractor? That answer is no. All design doesn’t need to be upfront. We couldn’t pull it off anyways, but it could also be costly and obstructive for many small or simple project applications. Is there value to having upfront involvement? Absolutely - when it’s done well. Consultants provide tremendous value, all-around, when:
Do consultants need to be doing fully-detailed layouts to accomplish this? Often no, though sometimes it could help. HOW DO WE RESHAPE THE WORK? In an SFPE Magazine Article in 2022, Thomas Gardner wrote “There is a happy medium between no delegation and full delegation of the fire protection system.” Count me in that camp. Many times when the subject of “Delegated Design” gets brought up, we instantly jump to extremes. Either all design should be by the EOR, or no design should ever be by the EOR. On one hand we have many military projects that specify the Qualified Fire Protection Engineer (QFPE) to be in direct charge of the layout upfront, if they don’t perform it themselves. On the other hand, we have an ever-growing amount of residential projects in North America that have no FPE or consulting involvement whatsoever. Both of these situations are not necessarily at odds. We can strike the balance between the two, and we can do “Delegated Design” better than what’s being done today. We can improve the quality of upfront documentation that defines scope and goes out for bid, and at the same time, still provide flexibility for the contractor and an overall lean project delivery. Part of solving that puzzle is looking realistically about what different approaches mean – how they look – seeing good and bad examples – and moving forward to introduce, educate and advocate on what better “Delegated Design” means in the future. For literally the past two decades there has been growing momentum to bring light to the issue. We’re not far from having more resources to define what “better” looks like and how we can easily get there. WHAT'S YOUR TAKE? We had a great dialogue about the problem of Delegated Design before, that's here. But what's your take on why work isn't provided upfront? Is it just tradition? Just the way things always have been? Is it any of the reasons I've cited? Why is our delivery method so different from Mechanical, Electrical, Plumbing or Structural? What separates us from other disciplines? Comment below - would be happy to hear your take. We tried out something new a couple months ago with a Detail Pick-Apart covering a dry sidewall sprinkler at a deck. We had a great response - healthy discussion from a wide variety of perspectives. Way back when we even talked about different parts and purposes for components of a wet riser. It's the dialogue that I often find the most helpful in seeing and understanding perspective that I simply just don't have. No detail is perfect, nor is it applicable in all situations. No way. It's one possible solution to some situations. That said, it can be really helpful to have open discord and learn from it. Quick rehash on ideas for critique and discord: USE CASES: What are good use cases for this? PROS: What benefits does an approach like this bring? CONS: What are the negatives with an approach like this? IMPROVE: What ways can this approach be improved? What critique would you offer here?
Thanks, as always, for being part of making the industry better. It's been quite the year! First - I'm thankful for you being a part of the community here. Whether it's reading a post here or there, downloading a cheatsheet, posting on the forum, using a tool or learning on the University platform - I couldn't be more thankful. You have helped make a dream of mine come to reality where I get to focus on ways to improve the industry I care so much about. Thank you for helping make that happen. Second - a lot has happened this year. We ramped up the learning experience with a load of new resources and 360-virtual simulations over at MeyerFire University. Perhaps just as impactful, we brought about an entirely new and improved site complete with an iOS and Android app. A lot has happened in that space over this year. In case you missed it, here are the top articles and resources of all time (as of 2023) at MeyerFire: #10 IS A POST INDICATOR VALVE REQUIRED FOR MY PROJECT? A code path study that looks at when post indicator valves are actually required. #9 A THRUST BLOCK CALCULATOR A calculator which helps size thrust blocks for underground pipe. #8 REQUIREMENTS FOR DRAINS IN FIRE SPRINKLER SYSTEMS A recap of when, where, and what size drains need to be in a fire sprinkler system. #7 FIRE HYDRANT FLOW TEST CHARTS A few pages for immediate flow translations for different fire hydrants. Useful for flow testing. #6 ARE FIRE SPRINKLERS REQUIRED FOR A CANOPY? A flowchart look at when sprinklers are required below a canopy, overhang, or porte-cochere. #5 A FIRE DEPARTMENT CONNECTION CHEATSHEET A PDF of all the biggest requirements & tips surrounding FDCs. #4 DETAILS AND REQUIREMENTS OF THE INSPECTOR'S TEST A breakout of the different requirements associated with an inspector's test. #3 SUMMARY OF DIFFERENCES IN NFPA 13, 13R, & 13D A breakout of the big differences between the three fire sprinkler standards. #2 BREAKING DOWN COMPONENTS OF A FIRE HYDRANT Types, components, and the "why" behind different parts of a fire hydrant. #1 COMPARE FLOW OF K-FACTORS WITH K-FACTOR CALCULATOR A tool (paid tool as part of the Toolkit) that optimizes flow and pressure across different available fire sprinkler k-factors. Thank you for another great year in helping improve the industry. I can't begin to tell you how excited and optimistic I am about what we'll be able to impact moving forward. Here's to 2023, and a bright year ahead. Cheers. - Joe Are you and others on your team looking for accredited professional development hours to wrap up 2023? Cash in and round-out unlimited continuing education requirements with MeyerFire University. We are a NICET Recognized Training provided and International Code Council Preferred Educational Provider, so all of our courses are NICET and ICC certified. With just one subscription you can get as many continuing education hours as you'd need, and still have the subscription active for your 2024 requirements next year as well!
Plus, you're in control of who uses your seat throughout the year - so you can remove yourself and add in others throughout the year for year-round learning. If you've been on the sidelines debating whether to join - now is a great time! Visit https://www.meyerfireuniversity.com to learn more today. |
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+ Unsubscribe anytime AUTHORJoe Meyer, PE, is a Fire Protection Engineer out of St. Louis, Missouri who writes & develops resources for Fire Protection Professionals. See bio here: About FILTERS
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