Decoupling Boiler and Installing Water Heaters in Century-Old San Francisco Apartment House Brings Relief to Residents Nothing lasts forever. That is especially true with mechanical fixtures, where the corrosive nature of water, the environment in which units are located and frequent use all work against fixture longevity. Nearly a century of service isn’t forever, but Read more
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Decoupling Boiler and Installing Water Heaters in Century-Old San Francisco Apartment House Brings Relief to Residents
Nothing lasts forever. That is especially true with mechanical fixtures, where the corrosive nature of water, the environment in which units are located and frequent use all work against fixture longevity.
Nearly a century of service isn’t forever, but it’s a pretty good run. Some steam boilers, especially in inner-city buildings, that were installed in the 1920s and ‘30s are still in service. The reliance on steam-heated buildings in that era was a “direct result of theories of infection control” to help fight the global pandemic of 1918 and 1919, according to a Bloomberg article in 2020. Masks, shots and forced isolation fought against the most recent pandemic, but a century earlier the solution was far simpler – open the windows.
The theory followed the correct premise that fresh air would help fight off airborne diseases. In New York City, for instance, the Board of Health ordered windows to remain open to provide ventilation – even in winter. Steam heating and radiators thus packed plenty of punch. They provided heat for building residents on the coldest days and with windows open. Efficiency, obviously, was not top of mind when the boilers were installed.
In San Francisco, Excalibur Water Heaters solved a heating issue for an 8-bedroom apartment house that relied on a steam boiler that been in place since the building opened in the 1930s. The steam boiler provided hot water and radiant heat. “Because of the age of the boiler, the hot water was never reliable,’’ said Anthony Achermann, one of the owners of Excalibur.
An 8-unit apartment house in San Francisco solved a problem with hot water delivery by installing two American Standard Water Heaters to replace an aging and faltering boiler.
Excalibur designed a solution that solved the problem in just one workday. The company installed two American Standard Water Heaters to provide hot water to the building. Due to space limitations, Achermann’s team used two 50-gallon tanks instead of one 100-gallon tank. Even more interesting, the ancient boiler remained in place and will remain the heating source for the apartment house.
A Hot Mess
The simple solution would have been to repair the ancient boiler – again – or install a new one. Achermann knew neither would be terrific options.
Replacing the steam boiler would have required a lengthy wait due to supply chain issues. The boiler had been repaired and serviced frequently, but few products that are nearly 100 years old work like they did when they came out of the box. In addition, many repair technicians avoid a challenging boiler replacement project.
“Most plumbers in this industry when they see a boiler, they run,’’ Achermann said. “Boiler service people are few and far between these days. Retrofitting any building with a boiler is hard.”
The boiler – “about the size of MINI Cooper,” Achermann said — operated on a timer, so hot water availability differed throughout the day. “Sometimes hot water was readily available,’’ Achermann said. “Other times it was lukewarm or no hot water.”
Steam boilers undergo significant stress and age over time. Poor water chemistry, corrosion, extreme temperature shifts and even the environment where the boiler is installed can contribute to the degradation of a unit.
Caustic embrittlement due to corrosion is a serious form of boiler metal failure. Even worse, chemical attack of the metal is usually undetectable. Failure occurs suddenly, often with catastrophic results. While aging, the apartment house boiler still has enough juice to provide heat. Perhaps it will need to be replaced at some point, but for now it serves the building. Certainly, the building owner can hardly quibble after receiving a lengthy amount of service from the heating beast.
The project was part of a remodeling of the apartment house. “The steam boiler was as old as the building,’’ Achermann said. “If they wanted to replace the boiler, they would have had to wait weeks, if not months. It was a common problem, but I’m seeing it less and less. When I come into a situation like this, I try to identify an out-of-the-box solution that can solve the problem.”
Due to the tight footprint of the mechanical room, Excalibur Water Heaters installed two 50-gallon tanks instead of one 100-gallon tank.
Splitting Service
Achermann solved the issue by decoupling the boiler from providing hot water. The in-place boiler still runs the heating system for the apartment house, but his team installed two American Standard Water Heaters for the building’s hot water service.
Because of space issues, Excalibur installed two 50-gallon tanks. “We didn’t have the space or the height clearance to install a 100-gallon tank,’’ Achermann said. “It was a pretty tight fit.”
The durability of the American Standard Water Heater brand was important to their inclusion in the project. “Over the years, water heaters have been getting lighter, they are making the walls on many brands thinner,’’ Achermann said. “Over time, water will try to corrode the tank. Anode rods are supposed to prevent that, but eventually they’ll leak and fall apart. The water doesn’t have anywhere to go, and it leads to leaks. By having a heavier tank, it’s buying more time.”
One of the most dangerous tasks for the project involved separating the boiler and installing the water heaters. With the gas and water lines coming into the building, the team took extreme care to complete a smooth transition.
“It’s important to understand the severity of what could happen if something goes awry,’’ Achermann said. “If something goes wrong, it could create a pressurized vessel that can cause an explosion. We had to make sure the steam radiators work appropriately, and that the boiler only has to make the steam.”
Additional Benefits
The warranty and burner assembly on the American Standard Water Heaters also factored into the selection for the project, Achermann said.
“With many manufacturers, the water heaters just make it past the warranty,’’ Achermann said. “The American Standard Water Heaters last well past their warranty date. They are also the only manufacturer in the San Francisco area that uses a mechanical gas control valve.”
The gas control valve is a traditional assembly that has served the industry well for decades. Many newer models have electronic assemblies that break down far earlier. “The electronic ones are harder to repair, while the mechanical heaters are much more robust overall,’’ he said. “I was getting tired of explaining why a unit we installed two years ago was failing.”
Workers completed the 10-hour project safely, and tenants celebrated that consistent hot water would flow to their apartments without interruption. “They’re excited because they now have consistent hot water,’’ Achermann added. “Sometimes it would take 3-4 minutes. We installed a recirculation pump and now the water gets hot within seconds.”
Overall, the project married Excalibur’s ingenuity, durable products and working with mechanicals already in place. Sometimes plumbers don’t have to re-invent the wheel. Making a few subtle tweaks saves time, money and energy, even if the units were around during the Hoover administration.
“It was a project that required some creativity as to how we could solve the problem,’’ Achermann said. “We came up with a good concept and the owner and the tenants are happy.”
Thomas Renner writes on trade industry topics for publications throughout the United States.
Bozeman, Montana is a city on the move, no doubt about it. As the nearest major passenger airport to Yellowstone National Park and the city nearest Big Sky Ski Resort, “Boz-Angeles” is currently growing at a rate of 3.2% annually. Its population has increased by 42.9% since the most recent census, which recorded a population Read more
Bozeman, Montana is a city on the move, no doubt about it. As the nearest major passenger airport to Yellowstone National Park and the city nearest Big Sky Ski Resort, “Boz-Angeles” is currently growing at a rate of 3.2% annually. Its population has increased by 42.9% since the most recent census, which recorded a population of 53,293 in 2021.
Of course, housing demand is rising, so the addition of a five-story mixed-use residential building fit in well with the City of Bozeman’s vision for its future downtown and added much-needed housing stock. The Merin is a mid-rise building that features 31 living units above two ground level retail spaces, with 35 parking stalls. Encompassing over 71,000 sq. ft., it will also feature a courtyard, and private balconies for the residential units.
The ability to laser scan the building to get extremely accurate measurements on floor and wall penetrations allowed Harvey’s Plumbing to accurately model and then prefabricate and quickly install the plumbing using Allied BIM software.
DCI Engineers designed the primary framing systems for The Merin’s podium-style construction (post tensioned concrete slab design for the ground level and wood framed above-grade levels). The engineering team also designed the building’s cantilever sizes to maximize the efficiency of the concrete slab and provided maximum economy of the post-tensioned concrete system by coordinating regular column spacing for the ground floor layout.
Plumbing planning
The project ground broke in the fall 2019 and was off to a good start when ownership changes jostled the plumbing installation schedule. The project used Aquatherm polypropylene piping for the domestic cold-water mains, Uponor PEX in all the units, PVC for the drain and waste, and cast-iron risers on toilet stacks, with copper stub outs coming off the water heaters.
Harvey’s Plumbing, a Bozeman-based, full-service plumbing and mechanical contractor was tabbed for the project’s plumbing installation (Harvey’s was subsequently purchased by Bozeman-based Williams Plumbing and Heating). Harvey’s had recently completed three similar projects in the Bozeman area, so the project was straightforward, and there was an established process for the plumbing installation, resulting in less time spent modeling the plumbing system design. Still there were challenges.
Harvey’s Plumbing saved an estimated 20% on the Merin job by prefabricating plumbing assemblies and spools in the shop using Allied BIM software and an automated laser positioning system.
According to Mitch Rausch, Director of Preconstruction for Williams Plumbing/Harvey’s Plumbing; “It’s a pretty typical downtown Bozeman multifamily condo unit and it worked out pretty well. The only real issue we ran into on that job were owner finish changes and material delays.”
By June of 2020 COVID had become a factor and while the pandemic didn’t necessarily slow the job down, it did cause a staffing issue for Harvey’s. “We definitely had to deal with lack of manpower just because it seemed like we always had one guy out for about a year.”
Harvey’s crew mix on the project included a superintendent, two then-recently tested plumbers, two apprentices, and two laborers. “We had a pretty young crew over there and that’s where that modeling really kind of benefited us,” he added.
Modeling efficiency – through software
The modeling of the plumbing system’s design was much quicker and more efficient on this project because Harvey’s was able to maximize its laser positioning system, a semi-automatic TigerStop saw, by connecting it to Allied BIM. Allied BIM is a new design-to-fabrication software program created by Bob Harvey, (previous owner of Harvey’s), and Brian Nickel (who had been Harvey’s Virtual Design & Construction Manager).
Allied BIM software and an automated laser positioning system help tremendously with building efficiency.
The duo cofounded Allied BIM in 2019 with the intent of improving the prefabrication process in the PHVAC, electrical, siding and framing, and modular building industries. “The machine shop is disconnected from the designers, and the field is disconnected from the shop, and we saw a way to build it better,” Nickel said of the venture.
While Harvey’s had been honing its modeling and prefabrication processes for years, for a shop its size, it was far head of the industry back in 2019. Traditionally, prefabrication shops get a designer’s drawings on a thumb drive or sheets of paper and a fabricator manually enters those instructions into a machine, which cuts the parts. A single error in that process can lead to expensive mistakes, such as ordering too many materials by as much as 40%, as well as huge material-waste-ratios.
Allied connects digital models directly to prefabrication machinery, eliminating errors and waste, while improving safety, trackability, and connectivity. According to Harvey, using traditional manual workflows, designers can send a fabrication shop about 10 drawings a day, but with Allied BIM’s automated data flow, they can send as many as 80 spools a day — an 800% productivity gain. Plus, the connectivity allows data to flow bidirectionally, allowing the fab shop to send the design team real-time updates and requests for additional instructions.
Software solves staffing shortage
Harvey’s had used Allied BIM on some of these previous similar condominium projects but connecting it to the TigerStop was what prompted a huge change in productivity. “At that time, we were still fully Harvey [not yet part of Williams], so we were a pretty small shop at the time, and in order to get the prefab done we would have to pull the plumbers off of the jobsite, bring them into the shop, and have them prefab it,” Rausch explained.
“We didn’t have dedicated fabricators. That’s about the time we started to add them. We had one part-time guy in the summer, he didn’t have a lot of experience, but he did some of it. And then if we’d pulled two key guys away from the jobsite, the general [contractor] would get upset even though we’re still making progress on the project. But it allowed us to do that pretty efficiently without losing too much presence on the jobsite.”
A load of PVC is lifted into place for unloading into a second-floor window at The Merin. According to Harvey’s Plumbing’s Mitch Rausch, the ability to get the right prefabricated assemblies to the right spot on the job provided a huge savings.
Improved safety was also a bonus. Using Allied BIM and the semi-automatic TigerStop allowed non-jobsite personnel to cut, prep and place the parts in bins so that they could be shipped to the jobsite where field installers could just plug them in. “It allowed us to really ‘lean up’ what we were doing and fit some stuff into our schedules that normally we wouldn’t be able to, and that the project schedule wouldn’t have really allowed us to do,” Rausch added.
Harvey’s Visual Design & Construction Engineer, Baylie Frost, performed all the modeling on The Merin project. “She was the only one working on modeling it, and she only had so much time, and she was also helping as project manager,” Rausch said. “So, if we were to tie her up making spool sheets, we would’ve had to add another BDC [building design construction] person to that project without Allied.”
Frost estimated that her spooling time on the project was reduced by 50% or more thanks to using Allied BIM, and labeling the spools was completed at least 10 times faster than the traditional method, while it also provided major organizational benefits.
Rausch also explained that using the Allied modeling and the TigerStop saw allowed them to limit wasted pipe sections to “just very, very small wafer pieces of pipe.” “I bet there’s at least 20 to 30% there in savings in PVC.” He added that an even larger savings came from fabricators not wasting time trying to salvage smaller pieces of pipe. “Traditionally, you’re going to have scraps and you’re going to have to pick up that scrap and try to cut up that scrap and use it. And that’s where you waste your time.”
Allied BIM software, laser scanning, and a Microsoft HoloLens mixed reality headset allowed the Harvey’s team to be very exacting when it came to the design and installation of The Merin’s plumbing system, delivering a profitable project, and meeting a tight deadline.
With Allied BIM and an automated saw, the operator does not need to pull out a tape measure, hold it to the pipe, and mark it, he or she can just focus on the saw. Thus, they’re less likely to incur an accident. “It’s taking some of that ‘thinking’ and some of that extracurricular stuff you’d have to do away, so you can really focus on just cutting the pipe,” Rausch said.
Additionally, Harvey’s was able to streamline their bid on the job knowing that they would be achieving some time, labor, and material savings thanks to their model-to-design process. While there were several mitigating factors on The Merin project, Rausch said that when it comes to modeling and exporting a design, spooling it, prefabricating it offsite and installing on a jobsite, that 20% labor savings are extremely realistic.
Savings trips up and down the stairs
Rausch explained that Allied BIM also helped enormously with the organization of piping materials. “With this job, there are five flights of stairs in them. And you’ve got to go up and down the stairs every time you don’t have a part or piece you’re fitting. And if we can model it and fab it and get everything grouped together in a nice, clean kit and get everything into that room at one shot, just saving a couple trips up and down the stairs every day for 8 to 10 guys, makes or breaks a job.
So, it’s the efficiency you gain by that. Out of everything we do, if we could have everything sitting there for the plumber to install in that unit, it saves trips looking for parts, having the wrong part, having something messed up. That’s the difference between making money and not making money, 100%.”
Welcome to another edition of our Hub Spotlight series where do a deep dive into the men and women who make the trades great. This spotlighted tradesperson tells us that he really enjoys trashy reality TV. “Nothing like kicking your feet up and watching someone making horrible life decisions on 90-Day Fiancé on a Sunday Read more
Welcome to another edition of our Hub Spotlight series where do a deep dive into the men and women who make the trades great. This spotlighted tradesperson tells us that he really enjoys trashy reality TV. “Nothing like kicking your feet up and watching someone making horrible life decisions on 90-Day Fiancé on a Sunday evening.” Joking aside, for Keith McGillivary (@mps_207)—full-time business owner of McGillivary’s Plumbing Services (MPS), Gardiner, Maine, for the past two years—his story into the plumbing trades is an interesting one.
McGilivary’s path started in a small town when a small plumbing business was looking for a helper, and he was looking for a job. “Little did I know it would be the start of where I am now,” says McGillivary. Before college, McGillivary started working for a small plumbing business that primarily focused on service work. The owner, Russell, was/is a great mentor and really took the time to help him understand not only what they were doing, but why they were doing it.
After deciding to pursue plumbing, McGillivary attended Southern Maine Community College (SMCC) for its plumbing and heating program. Through college, he continued to work alongside his mentor, and after graduation, continued to work for him full time for three years. McGillivary then took a job at Bath Iron Works (BIW) as a pipefitter building destroyers, ships for the United States Navy. “The piping systems were complex, and although it was “plumbing on a ship,” it was completely different. I found it fun to learn the ins and outs of that particular plumbing,” says McGillivary.
Eventually, McGillivary joined the Pipefitter Test Crew and tested the piping systems after they were built. He worked there for six years, but the whole time he continued to work nights and weekends doing plumbing work on the side. “This allowed me to gain hours and knowledge for my Master’s test. After passing my Masters, I decided to make the plunge into self-employment because I wanted the schedule flexibility for my family,” says McGillivary.
In fact, McGillivary’s biggest motivation for self-employment was time, rather than money. “I have learned to set firm boundaries for myself when scheduling and taking on jobs. I have been able to take more time off for my family than ever. Being a service plumber, in this day in age, you could work 24/7 if you wanted. I try to work ‘normal’ hours, and if I can take a day off for family stuff, I always do,” says McGillivary.
Shout Out to Mentorship
According to McGillivary, Russell taught him everything he knows about plumbing and owning a business. “He taught me all the hands-on work, how to write estimates & bid on jobs, customer relations, and how to balance a small business/family life,” says McGillivary.
And McGillivary wants to pay it forward. “I definitely consider myself a role model for others looking to join the trade. I feel I am a good example that hard work and dedication pays off,” says McGillivary. “My mentor was so important to my journey that I try to give back what I can by being transparent about my plumbing knowledge.”
Uplifting the Trades
Recently, there has been a big push for kids to attend trade school so there has been a shift in younger people showing interest, says McGillivary. “Trade school was beneficial for me to learn the code side of things, in an environment different from the hands-on work. I think we could get more interest in the trades if the schools showcased all the different avenues someone could go once they completed their schooling, and the financial opportunities that come with them. Everyone expects a doctor to make six figures, but not everyone knows you can make that in the trades without massive student loan debt,” says McGillivary.
“Everyone expects a doctor to make six figures, but not everyone knows you can make that in the trades without massive student loan debt.”
Social media can also be used to attract more people to the trades. “I see it all too often when guys in the trade are way too harsh on people for asking questions on Facebook plumbing pages. There are so many people asking questions for the purpose of learning and gaining knowledge. We were all there at some point, so be kind enough to answer the questions in a helpful manner. Social media can also be used to form “new-to-the-trades” communities and to provide seminars,” says McGillivary.
Social media also has played a huge role in the growth of McGillivary’s business. Starting as a small, part-time business with the help of word-of-mouth recommendations on small town Facebook pages, which made McGillivary realize that social media could be used to showcase the work he is doing on a day-to-day basis. “I use my Instagram to show what I am about as a business and the work I put out. I have found that if a customer can see why you are more expensive than the other guy, then they are more likely to go with you. I use it as an open-door insight to my business both in reels and daily stories,” says McGillivary.
McGillivary uses social media to learn little tricks of the trade that he just wouldn’t have been exposed to, being from such a small town. For McGillivary, it is extremely beneficial to be able to have conversations with such great tradesmen. He also talks to apprentices daily or weekly about projects, and gives them advice. “I wish when I was learning, I had this platform to learn and meet others. As visual learners, much like a lot of trades guys I know, it’s changed the way we can learn,” says McGillivary.
Making Time
Summers in Maine are short, so McGillivary tries to spend every nice weekend camping in his camper. In the winter months you can find him on his snowmobile at camp. “I would love to ride my snowmobile from camp in northern Maine to the Gaspe Peninsula to complete the “Great Gaspe Snowmobile Tour,” a six-day, 1,500-mile ride around some of the best trails,” says McGillivary.
And the last day McGillivary said it was a great day? “You know it’s funny, as I look back on just yesterday—camping with my family, beautiful weather, everyone smiling, does it get much better than that? So, the answer to that question would be yesterday!”
Go-To Tools on the Job
According to McGillivary, his go-tools are a couple pairs of Knipex Cobra pump pliers, a 6-in-1 screwdriver, and an adjustable wrench. Any good service plumber can fix most things with those!
Also, I find myself feeling naked if I don’t have my Leatherman Wave on me. Another great tool that has many uses.
Lastly, if there was one tool that changed the service plumbing game, it’s the M12 Milwaukee press tool. If you’re running a service company and don’t have one, you’re late to the party.
Eric Aune with Mechanical Hub joins American Plumber Stories for a “Signing Day” special at the Build My Future event, hosted by the Iowa Skilled Trades. Take a look at the exhibitors and the hands-on experiences offered for students considering a career in the trades. Iowa Governor, Kim Reynolds, also presents at the celebration and Read more
Eric Aune with Mechanical Hub joins American Plumber Stories for a “Signing Day” special at the Build My Future event, hosted by the Iowa Skilled Trades. Take a look at the exhibitors and the hands-on experiences offered for students considering a career in the trades. Iowa Governor, Kim Reynolds, also presents at the celebration and signs each student’s letter of intent as they commit to their future in the trades after high school.
By Aaron Stotko When a century-old Dallas railroad company headquarters required major renovations to transform into a Homewood Suites by Hilton, initial cost estimates for the hydronic heating system came in too high. That’s when City Wide Mechanical of Dallas looked to alternative piping systems for a solution. They found PEX-a pipe with F1960 expansion Read more
By Aaron Stotko
When a century-old Dallas railroad company headquarters required major renovations to transform into a Homewood Suites by Hilton, initial cost estimates for the hydronic heating system came in too high.
That’s when City Wide Mechanical of Dallas looked to alternative piping systems for a solution. They found PEX-a pipe with F1960 expansion connections to be the ideal system, due to its durability and ease of installation in addition to the job-site productivity, safety and, best of all, profitability potential it provided.
And City Wide Mechanical isn’t alone in their findings. Many mechanical contractors are discovering the benefits of PEX-a pipe and F1960 connections as the preferred alternative to copper, iron, and steel, which have dominated the mechanical piping industry for decades.
Benefits of PEX-a
PEX is an acronym for crosslinked polyethylene. It has been used in North America since the mid-1980s, starting with radiant floor heating systems, then moving into plumbing and, eventually, to hydronic hot-water heating and chilled-water applications.
PEX can be manufactured via three different processes, which create products with varying crosslinking percentages that allow for different characteristics. PEX-a is the most durable, flexible, and resilient with crosslinking around 85%. PEX-b is a stiffer piping product with crosslinking around 65% to 70%, and PEX-c features crosslinking around 70% to 75%.
ASHRAE Headquarters Grand Opening Fall 2021, photos by Devin Abellon
One major benefit of the higher crosslinking in PEX-a is its extreme flexibility along with its thermal and shape memory. The flexibility of PEX-a eliminates most connections in smaller-diameter piping, saving time and money with up to half the connections required in rigid metal piping systems. To make a change in direction, the installer simply bends the pipe instead of having to stop and make a fitting. There are also bend supports available that help hold a bend securely in place.
The thermal memory of PEX-a provides kink repairability with a simple shot of heat from a heat gun. This eliminates the need to add in a coupling if a kink ever occurs in the pipe. (It is important to note that kink repairability is not possible with PEX-b or PEX-c pipe.)
The shape memory of PEX-a allows the pipe to expand and contract back down to its original shape. This makes it extremely resilient in freezing conditions and also provides for the fastest, easiest, most reliable PEX-a fitting system — F1960 expansions.
Expansion fittings require one simple tool to expand the pipe and an expansion ring before inserting a fitting. As the pipe and expansion ring naturally shrink back to their original shape, it creates a strong, durable connection that holds tight and can never be dry-fit. (Note: It is not recommended to expand PEX-b or PEX-c pipe due to microcracking that can occur.)
The innovative expansion fitting method eliminates torches, glues, and solder from a job site for greater worker safety. Plus, the system is extremely easy for installers to learn, helping get new crews up to speed quickly.
Speaking of job-site safety, PEX is also much lighter in weight compared with metal systems. For example, a 300-foot coil of 1/2-inch PEX weighs about 18 pounds, whereas the same amount of copper pipe weighs around 85 pounds. The lighter weight of PEX makes it safer and easier for installers to move around a job site and also eliminates the need for heavy-lifting equipment.
PEX-a also has a long-term advantage over copper when it comes to performance longevity. It is a static system, meaning its internal surfaces — which are three times smoother than copper — will not pit, scale, or corrode. That means its performance will remain the same from day one through decades of use.
Finally, because it is not a traded commodity, PEX-a holds a relatively stable material cost. This makes bidding a project much more consistent and reliable.
Application Details and Installation Tips
PEX-a is regulated by the ASTM F876 standard, which denotes temperature and pressure ratings of 200°F at 80 psi (pounds per square inch), 180°F at 100 psi, and 73.4°F at 160 psi. These values are well within the range of operation for most hydronic systems, including chilled beams, fan coil units, baseboards, radiators, hydronic VAV (variable-air volume) reheat coils, and radiant manifolds.
Because PEX is oxygen-permeable, it is important to use a pipe with an oxygen barrier that limits oxygen diffusion to levels below DIN 4726. This will protect the metallic components in the mechanical piping system, such as valves, strainers, and pump volutes, from corrosion.
The pipe is manufactured in sizes from 5/16 inch up to 4 inches and features a copper tube size (CTS) outside diameter. This means all the off-the-shelf components used in a copper hydronic piping system — hangers, supports, and insulation — can be the same.
For horizontal piping, the industry offers PEX-a Pipe Support — a galvanized-steel channel that is 9 feet in length and available in PEX pipe sizes from ½ inch to 3½ inches. This solution enables hanger spacing similar to copper pipe and helps control the natural expansion and contraction of the pipe as it heats and cools.
Because PEX-a expands at 1.1 inches per 100 feet per 10°F Delta T (which is 10 times that of copper), installing anchors every 65 feet and using PEX-a Pipe Supports allows PEX-a to function much like a copper system. In fact, different installation methods have a different effect on the overall net expansion rate.
With a strut-and-clamp system, using PEX-a Pipe Supports and anchoring with fixed points reduces the expansion rate of PEX-a to 0.08 inches per 100 feet per 10°F Delta T (a rate less than copper). And a loop-and-clevis system can reduce the rate to 0.12 inches per 100 feet per 10°F Delta T.
If you’d like to learn more about PEX-a piping systems, visit the Plastics Pipe Institute at plasticpipe.org or the Plastic Pipe and Fittings Association at ppfahome.org.
Aaron Stotko is the director of Segment Marketing at Uponor. He can be reached at aaron.stotko@uponor.com.