The community here is second to none - after a post on my personal list of ideas for getting 'unstuck' in hydraulic calculations last week, I received a handful of encouraging emails and a string of great commentary. Being an engineer and a son of two accountants, I can't help but turn those everything into a spreadsheet. With the tips last week and great feedback sent in, here is a PDF tipsheet that includes a quick rundown of ideas to consider when fine tuning and getting 'unstuck' while running fire sprinkler hydraulic calculations. Click the image or link below to download.
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I can usually tell when I’m carrying extra stress in my life because my nightmares looks suspiciously like a hydraulic calculation that, despite any refinement, just doesn’t calc’ out. Ever had that? I’ll refrain from sharing all my personal issues for now, but if you’re a sprinkler designer or FPE, you’ve had to experience a project where there’s seemingly no way to get the hydraulics in the black. When I initially lay out a project I’ll have a rough idea of pipe sizing and layout type (tree, grid, loop) based on similar projects. I’ll lay out a remote area and ‘rough-in’ the rest of the design so that I can get to hydraulic calculations iterations as early as possible. Iterations? Yes, iterations. If you’re long versed in the sprinkler industry this needs no explaining. If not, the secret sauce of a high-value designer/engineer is all in the refinement and iterations. If you’re a consulting engineer, perhaps you’re less interested in whether a system is efficient and more interested in whether a system ‘can work’. If you’re on the install side of the trade, you can earn back good pay and more by calculating systems that are well optimized – that is – perform efficiently, use the right system type, sprinkler type, and allocate pipe sizing appropriately. This week I’m running down a quick list on potential avenues to consider when you’re working through those calculations and need ideas on tweaks that could help. A quick disclaimer – hydraulic calculations are an important part of ensuring that the systems we design will be effective in suppressing a fire. The categories below are important aspects to consider when conducting hydraulic calculations – not corners to cut – but rather ideas to get unstuck in optimizing a sprinkler system. System Type Probably most important consideration is the system type (grid, loop, or tree). Dry and pre-action systems have limitations (no grids allowed), but if a facility is big enough then moving to a loop or grid configuration may significantly help the system perform more efficiently (ie: smaller size pipe). Sprinkler K-Factor This perhaps could be the most often-overlooked impact on a sprinkler calculation. Are you using the right k-factor for the job? If you’re always using K5.6 until you get into storage applications – there are better tools for the trade. Adjusting the k-factor based on the density and sprinkler spacing directly impacts the starting pressure within a hydraulic calculation. If you haven’t tried it yet, use this tool that’s a part of the Toolkit to find the optimal k-factor for your job. Pipe Sizing Perhaps the most obvious and classic go-to is adjusting the size of pipe diameters. The larger the pipe diameter, the easier (less friction loss) the water will experience when passing through the pipe. Pipe Schedule This isn’t always negotiable – many specified projects will stipulate a pipe wall thickness – but be cognizant that the pipe schedule is (1) correct for the job, and (2) is considered in the hydraulic calculations. I had long underestimated the impact that pipe schedule had on hydraulic calculations, but it’s major. Schedule 40 and Schedule 10 can have a major impact. Change from Schedule 10 to Schedule 40 and you’ll increase friction loss by 24%. See the impact on friction loss with the Friction Loss Calculator as part of the Toolkit here. C-Factor Also not a negotiable part of a project – c-factor directly relates to the friction loss under the Hazen-Williams method of hydraulic calculations – its nonetheless important to get correct. How can you improve the c-factor? The pipe type (plastic, copper, ductile iron or steel) and system type (wet, dry, pre-action, deluge) will impact the c-factor. One project I worked on had major challenges, including a quadruple-slam of dry system, sloped roof, tall roof, and poor water supply. The only suggestion we had to avoid a fire pump was to insulate and heat the building such that a wet system could be used. That change had a number of impacts, but the c-factor change from 100 to 120 for the pipe had a major bearing on the new system working. One major change that’s coming to the 2022 Edition of NFPA 13 is allowing a C-Factor of 120 to be used on new dry systems that are installed with nitrogen. I’ll be sure to explore this in more depth when the time comes. Sprinkler Spacing Are your sprinklers maxed out at the greatest possible coverage area? In some applications, this can hurt more than it helps. Yes, we might save on the cost of material and labor with a reduction in sprinklers, but reducing the area per sprinkler in a very tight calculation can have a positive impact with starting pressures and the densities achieved. See the density vs. k-factor calculator as part of the Toolkit to see the impact with various sprinkler spacings. Remote Area Size There are some reductions in allowable remote area size in NFPA 13. A common one is the quick-response reduction, which allows a smaller remote area size for systems which have low(er) ceilings and quick-response sprinklers. See the impact of remote area with the Remote Area Analyzer here. Water Source Height An often overlooked part of the calculation that has a major bearing on the result is the height of the water source. Many systems are designed based on a fire hydrant flow test. Is the elevation of that source accurate, relative to the jobsite? I once worked on a job where a submittal showed the source (city water grid) to be at an elevation of 0'-0" relative to the first floor of the building. I charted google earth and paid close attention to the listed source from the flow test report. While a hydrant existed about at ground level elevation, the actual static/residual hydrant where the test results were gathered was at an elevation 27-feet below the project grade. It was a substantial hit to the hydraulic calculations (all calculations failed with the correct elevation shown). Backflow Preventer Loss On many systems the backflow preventer presents the worst pressure loss for any single piece of equipment on the system. It's easy as a designer to input a curve or a conservative static loss, run the calculation, and not return to the backflow preventer. However, if you're seeing high pressure losses, shop around. There are a variety of backflow preventers on the market, and using backflows that are straight (horizontal/vertical, not N- or Z-type) and use OS&Y valves instead of butterfly valves can offer some hydraulic savings. There's a whole database we've created on available backflow preventers as part of the Toolkit here: BACKFLOW DATABASE* Valve Types Just like backflow preventers, valves introduce pressure loss into the system. An OS&Y valve will remove the water-blocking paddle from the water stream, allowing water to pass through mostly unimpeded. Other valves like butterfly valves leave the paddle in place, causing some pressure loss. Sprig, Drop, On-Pipe, Flexible Drop & Return-Bend Configurations Ever looked at the difference between using sprigs and not using sprigs (on-pipe fittings or outlets) has on a calculation? If you're at a higher density, it can be significant. Hydraulic calculations are usually not a driver in whether sprigs are used, or whether return-bends vs. side outlets vs. bottom drops are incorporated - however - these have an impact on the calculations and can introduce pressure loss in between the sprinkler and the branch pipe. One notoriously high friction loss arena is use of flexible drops, which can add pressure loss with equivalent 1-inch pipe lengths of 20-70 feet of pipe. These friction losses can vary significantly among manufacturers and models. Riser Nipple & Sprig Diameters Have a storage calculation with high densities and a high sprinkler k-factor? It may be worth adjusting the sprig diameter to see the impact of the 1-inch diameter pipe. Similarly, riser nipples in-between a main and branch line bear the full flow from the branch line to the main. These pieces, while many times shorter than the spacing between sprinklers, can still introduce a pressure loss to the system that a stepped-up diameter can help. Special Application Sprinklers Lastly - is there a sprinkler specifically designed for the application you have? Many manufacturers over many decades have dialed-in and created sprinklers that are built for specific purposes (special application sprinklers). These product listings can allow different starting pressures and design criteria, which, as a whole, can help reduce the water burden on a system. Two that I often use that come to mind are residential and attic special application sprinklers. In both cases, use of those sprinkler types within their respective hazards dramatically reduce the water required at the remote area, thereby allowing smaller mains and equipment back at the riser. See a list of all available sprinklers on the market (filter & search) on the Sprinkler Database in the Toolkit. What Else? In the next post I'll look to put together something that's a little more handy as a checklist for entry and intermediate designers. In the meantime - what am I missing here? What aspect of hydraulic calculations do you think are often overlooked yet carry a big impact? If you work in and out of the residential design space, you may come across this question quite a bit. A couple of years ago I wrote on this topic and put together a brief summary of the differences from a design and code perspective. This one gained a lot of traction and attention, and was included in the National Fire Sprinkler Magazine's Member takeover in the September/October 2020 Edition. An updated cheatsheet is attached and includes some great feedback I've had since that 2018 article. Thanks & hope you have a great weekend!
Awhile back I mentioned there were some big projects in the works around here. This has been Number 1 on my list for over a year now. Last summer I threw out an idea that took hold, and since last November I've been thrilled to be a part of a project that I think will be a major help for industry professionals. The National Fire Sprinkler Association (NFSA) has published informal opinions on everything fire sprinklers for longer than I've been alive. Their Expert of the Day program answers real questions to the 'gray' areas of code with practical advice from leading industry experts. While these opinions have been collected and published monthly for decades, up until now they've never been assembled, organized, and published into a single resource. I'm thrilled to announce that this collection of expertise is now complete; the NFSA Expert of the Day Handbook is a two-volume, hardcover set of over 1,300 pages covering nearly 2,000 questions on over 585 topics relevant to fire sprinkler systems, standpipes, water supplies, inspection, testing, maintenance, codes and standards. Why am I so thrilled about it? I had the pleasure to work with NFSA by collecting, converting, and organizing all the expert inputs into these volumes. This was a concept I really wanted to see happen - and after sharing the idea of compiling the years of content to NFSA they were happy to fold me into the team on this project. It's now available for pre-sale with shipments starting in just a few weeks (late August / early September). If you are a sprinkler designer, engineer, inspector, installer, plan reviewer, code authority, or work in and around the fire sprinkler industry, then this handbook was built for you. Just in the eight months of reading and compiling the information I saved days of code research (thousands of dollars in billable hours) by having quick access to these expert opinions. Just as it is part of the mission of this site, I am wholeheartedly excited to see how these handbooks help promote best practices and share expertise with the industry. Check out more about this two-volume 1,300 page set and get a copy today. Questions? Comments? Shoot me a line at [email protected]. Determining the correct height of a fire sprinkler relative to structure and ceilings or roofs is not typically a difficult task. Yet, the more I explored the basic premise the more I realized how different the needs for each sprinkler type are. This week I've been working on a cheatsheet for fire sprinkler deflector heights. It's a flowchart that helps direct the sprinkler height and code reference based on the type of sprinkler. Click here to download a PDF copy. If you find cheatsheets like these helpful, consider subscribing to free tools like these here.
Take a look and let me know what you think. Thanks & have a great week! I hope you are having a great week. This week is a 2020 update to a popular post from 2016 with a free PDF cheatsheet. It's usefully for novice designers or experienced inspectors, with clear code references and purposes of each of the components that go into a floor control assembly serving a fire sprinkler system. A breakout of each of the components that go into a fire sprinkler floor control assembly.
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Last week I introduced a Remote Area Analyzer that evaluates remote area size and shape. This week could possibly be the biggest and best expansion of any tool created thus far. I'm thrilled to present a beta version of our Sprinkler Estimator tool. With a few default adjustments, you can quickly get a remote area's pressure and flow demand, remote area shape, and have a live schematic of the calculation that updates without a need for "re-running" the calculation. For a long time now I've wanted a tool where I could quickly estimate pipe sizes and a remote area's demands before I started laying out the system so that I could be as efficient in my design workflow as possible. What typically takes me 30 minutes to a couple hours can now be gathered in less than 30 seconds. Another fun application? Want to see what effect k-factors have on your calculation? What about long sprigs? Or what about pipe schedule changes? Wet versus dry systems? What about a consistent branch size versus changing pipe diameters? With this tool you can adjust parameters with just a click and see the live impact it has on your calculation. I'm really not trying to hard sell this one, I've just had my morning coffee and I'm thrilled to have you give it a try. It's been something I've thought about and developed piece by piece for a couple years now. The best way to experience it is with the downloadable version of the Toolkit. You can download the latest full version here. The downloadable version has a split-screen that shows the live preview and live calculated results while also allowing you to adjust parameters... no scrolling required. Click here to give it a try on our cloud version, and shoot me an email at [email protected] if you have any feedback or suggestions. Thanks and I hope you have a great week!
When I initially set up a hydraulic calculation for a tree-style sprinkler system, there are a few key points I have to consider. All of these points today and the tool are specifically for tree systems (not gridded). First, we need to determine what the remote area actually is. In NFPA 13, for instance, there are multiple adjustments (quick-response sprinklers, dry systems, sloped systems, high-temperature, etc.). Even if we start with a 1,500 sqft remote area, it could look a lot different after multiple adjustments. Second, we need to determine the minimum length of the remote area along a branch line. This is a relatively straightforward at 1.2 x √ (remote area size), but it's still another hand-calculation that needs to take place. We then round up to determine the sprinklers along the first branch line, then expand by branch lines to figure out how many sprinklers are actually in a calculation. The tool I'm introducing today (which is also now available on the Toolkit) is a schematic-level remote area analyzer that will apply multiple adjustments and quickly estimate the important parameters associated with a remote area. With only a few quick inputs, you'll see an initial remote area laid out with a live schematic of your situation. Click either of the images below to give it a try: A new remote-area analysis tool which incorporates adjustments and gives a live schematic layout. See it here. If you already have the toolkit, you can download this and three other recently added tools in today's Toolkit update here. If you're interested in giving this tool a try, check it out here. I'll have it up without any login credentials for a couple months.
In time, I'm looking forward to expanding this tool to have some powerful estimating abilities. Any suggestions, tips or feedback? Post a comment or shoot me an email at [email protected]. A Hurting World at Large Just like I don't ask hollywood to be my moral compass, you don't come here for my my personal opinions. I get it. That said there has been a tremendous amount of unrest here locally, nationally, and worldwide this past week. I think there's a major feeling that our collective perspective has to improve. I want to do better and be part of a better future for everyone. I want you to know that whoever you are and wherever you are, I very much care about you and your well being. You have tremendous value. Hope you and yours are safe, healthy, and doing well. Thanks & I hope you have a great week. Did you know there are over 1,500 variations of sprinkler models which are actively on the market today? Around three years ago we began development on one of the largest research projects we've ever undertaken - organization of all the fire sprinklers available on the market today. It took several hundreds of hours to finely comb through all the k-factors, pressure listings, spacing distances, model numbers, responses, and links to websites and product data. The Comprehensive Fire Sprinkler Database In late 2018, we finally released it - a comprehensive Fire Sprinkler Database. With it you can search by SIN, k-factor, type, spacing distances.... most any parameter you need to in order to find the sprinkler that's the best fit for your design. The introductory video to it is here (forgive the terrible voice narrator... it was me): https://www.youtube.com/watch?v=DsLPg4GKaCU Updates from This Week Just this week we've updated the database to include recent releases for new sprinkler models from Tyco, Viking, and Reliable, including new window sprinklers, concealed sprinkler options, MRI sprinklers, institutional sprinklers, and corridor sprinklers. Use It Today If you haven't checked it out - here's an opportunity to do so. I've opened it up for everyone just for the next couple weeks. Just go to this link - www.meyerfire.com/sprinklerdatabase - and login using [email protected] as the username and sprinklerdatabase as the password if you're not already a Toolkit subscriber. The Fire Sprinkler Database is the most current and comprehensive database of available fire sprinklers across all manufacturers we know about. Click the image to login and try it out. What's Next?
For those in the inspection department - it's been asked how we can take this to the next level. Can we get obsolete and recalled sprinklers into the database as well, so that we can quickly search to find information on recalls? That answer is yes, but I need your help. I'm not regularly involved in inspections, but I know many of you are. If you have a good understanding of where all the various manufacturers recall information (old and current companies) and how I could best showcase that material, please reach out to me at [email protected]. I'd be happy to get some input on how I can tackle this next phase of the database and make it that much more useful for us all. Thanks & have a great week! While couped up in our house I've been binging on creating cheatsheets instead of Netflix. Sorry Tiger King. This week I'm debuting an overview of the components for seismic bracing in fire sprinkler systems. Seismic bracing is a nuanced and complex topic, but my hope with this overview cheatsheet is that you'll have a starting point for reviewing all the different requirements that go into seismic bracing. As always, be sure to check the code, the commentary, and any other information you can find on these topics to make sure your work or your reviews are top notch. That being said, here's the two-page introductory cheatsheet for seismic bracing in sprinkler systems under NFPA 13. If you find this content helpful, please considering sharing with colleagues and subscribing to resources like this here: www.meyerfire.com/subscribe. Thanks and have a great rest of your week! |
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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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