Building Principles: Some like it HOT—The REST of the Story
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Building Principles by Rick Stryker, P.E. In October of 2005, "Building Principles" looked at a budding project to replace the hot water heating system in a camp kitchen. Way back then, I promised that we'd return to the story when there was more to tell, so here's the "rest of the story" as radio commentator Paul Harvey likes to call it. After a winter of wrestling with the project, and a summer of operation, it's time to tell you how it all came out in the end. If you can, break out that back issue and read through the details. For those of you who don't archive Camping Magazine though, let's revisit the high points. The camp's kitchen needed a supply of hot water for food preparation, as well as hand and dishwashing. The dishwasher units were configured to sanitize the dishes at the rinse cycle with 180 degree water. The existing system was a cobbled together collection of propane fired boilers, a recirculating pump, and a leaky pressurized storage tank. The camp was considering replacing the single boiler with three modern boilers that the plumber believed had sufficient capacity, but the question of hot water storage (a regulated pressure vessel) remained a big question mark. The alternative was a technology called "tankless" But would it work? Originally, the plan was to use the summer of '06 to measure and record hot water and propane use. However, shortly after the October ‘05 article was written, it became clear that the units would have to be replaced before the next season, Autumn 2005 Water samples were collected and analyzed to determine whether and how much softening would be required. As it turned out, the hardness was within the acceptable limits. No softening would be required at all! Then we had to consult with the State agency that inspects boilers. In Pennsylvania, that's the Bureau of Labor and Industries. It turned out that there were several issues that we'd have to address before they would approve such an installation. The most difficult would be the requirement that the boiler design and construction had to be certified by the American Society of Mechanical Engineers (ASME). Many client camps in Pennsylvania avoid this requirement by purchasing several smaller hot water heaters that individually do not exceed a certain heating rate. For the tankless setup to work, the units which would deliver enough hot water for the kitchen would exceed the limit by more than two times. The units we had our eye on were not certified, and there was no intention to pursue it. Back to square one: research the market. We found one manufacturer which was within striking distance of meeting the requirement, but they weren't sure how long the final process would take. It was November and the clock was ticking. December passed and still no news, good or bad. Winter 2006 Finally, in the second week of January, we received word from the manufacturer's representative that the equipment had its ASME certifications and that these units would be on the market soon. How soon? "Maaaaybe late spring or early summer," they thought. We couldn't afford to wait until the last minute because even the conventional boiler equipment took weeks or months to order and deliver, and then there was installation time required. Using all of the information we had available, we worked with camp leaders to develop a timetable and decision tree that established a series of milestones that provided a preferred chain of events (installation of tankless heaters) but which incorporated a fall back plan if the preferred plan fell through. At the same time, we drew plans and prepared bid documents for both alternatives so that we could put either plan into effect on very short notice. By the time the snow melted, we were ready for [almost] anything. Spring 2006 In April, the supplier notified us that if we placed an order immediately, we could have the units at camp in two weeks. Fortunately, our timetable actually allowed four weeks, because in our haste, we actually ordered and received heaters configured for natural gas and not propane. They had to be returned to the factory (via standard freight!) and replacements had to cross on the way. While this was happening, we were signing a contractor to do the job and ensuring that his insurance was in order among other administrative requirements. The right units arrived the day before the contractor was supposed to install them. Luck? Sure! There was some luck involved, but much more, it was our plan—thought through and followed—that allowed things to work as they did. Summer 2006 Countdown to camp! The week before staff arrived, the kitchen staff came for precamp. Given the history of the hot water system, they were pretty skeptical that something like this would work at all, let alone meet the requirements of the inspectors. And briefly, it looked like things might not work out like we'd hoped. Two issues vexed us. The first involved reaching the required 180 degrees at the furthest dishwasher. The system delivered temperatures of 175, 176, 177, and even 178, but just not 180. The hot water distribution pipe was anchored to a long run of concrete, cinder block, and steel surfaces. These surfaces were wicking the heat from the hot water through the side of the pipe. Much of the pipe was inaccessible without nearly demolishing the building, so insulating the pipe wasn't an option. The cost of running new copper pipe (as well as the time required to do it) was more than we could stand. So ultimately, the answer was that one of the regular vendors carried a line of equipment designed to deliver a chemical sanitizing agent into the rinse water. The regulations allow a much lower working temperature with such a system, and this also removed the prospect of scalding the dishwasher operator. Two issues solved at once! The second situation involved a most mysterious behavior. The dishwasher rinse temperature (or the hot water in any sink) would stabilize with seemingly endless streams of hot water. Then suddenly, the temperature would drop as if the heater had gone out. We spent the best part of the day troubleshooting the heaters and brainstorming when we discovered that an improvised faucet, made from a pipe tee and two gate valves, had been installed outside for filling mop buckets. Any time that someone filled a mop bucket, hot water was recirculating back through the cold water system through this connection! By replacing the tee with a real faucet, the problem was solved, and the mysterious temperature drop never happened again. The inspectors and the kitchen staff were satisfied because there was ample hot water at the required temperature. The caretaker was ecstatic because he spent no time messing with broken pipes, leaks, or scalding recirculation systems. Functionally, the system was a tremendous success. The acid test now would be whether the systems had actually saved any fuel and money as promised by the manufacturer and the calculation estimates. Fall 2006 After some fairly quick data gathering, we were able to calculate that fuel consumption had dropped 25 percent from the previous summer. Since no other changes had taken place, the difference could only be attributed to the new hot water heating system. But there was more to the story than just the fuel savings. Let's look at what the camp's innovations provided in hard dollars in Figure 1. At first glance, it may seem that choosing the tankless heaters was a no-brainer since the equipment cost was about one third of the cost of the conventional boilers. But it's important to bear in mind the risk, planning, and management that were required to make everything come out alright in the end. The inspecting agency had to divulge the criteria (ASME certification) that would be required for them to accept the units. We had to find a manufacturer that could meet that specification, and then follow up until they could provide it. We had to locate a supplier who would stand behind the units in this application (new for them also!) as well as a contractor who felt confident installing them. Then we had to troubleshoot the system until we could find the cause for things to not operate as we had planned. Any of these obstacles could have derailed the project. But none did because of the forethought and careful planning that went into every step along the way. Certainly there were anxious moments as milestones were approaching, but still the time line provided a well-thought-out plan would allow camp to open on time. When it was all said and done, what did camp gain and how did those gains come to be? The most important step was being pro-active rather than re-active. By taking the bull by the horns, the leadership was able to manage rather than be managed by the situation. There was enough time to look for alternatives, enough time to develop a time line which planned for things to go awry, and enough time to adjust the plan along the way. Get out of reaction mode by looking around camp with a new eye. An opportunity to save big bucks might be right around the corner! Rick Stryker is a Professional Engineer (P.E.) whose practice specializes in study, design, consultation, and permitting for facilities and infrastructure at camps and conferences nation- wide. He can be reached at 570-828-4004 or at campfc@ptd.net. Originally published in the 2007 May/June issue of Camping Magazine. |
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