Water challenges, chemical interactions, and other factors led an Orlando MEP service company to polypropylene piping, which fit the bill perfectly.
Located in Leesburg, FL, Lake Port Square has 398 individual apartments located in two residential buildings and offers a “life care contract” guaranteeing that residents will never be forced to leave their home. In such a high-end facility, operation and maintenance - especially in the mechanical system - is taken seriously.
Orlando-based Westbrook Service Corporation has served as the roughly 14-yr-old facility’s mechanical system and maintenance contractor since 2005. The five-story, 287,000-sq-ft Lakeside East and its apartments (ranging in size from 600 sq ft to 1,860 sq ft) had been served by two original 450-ton centrifugal chillers.
In May 2006, Westbrook was hired to replace the existing chillers. However, when purging the air from the chiller system, leaks were discovered piping throughout the building. Westbrook’s general manager of commercial HVAC, Don Hammond explained that with the system pressurized to 110 psi, the schedule 80 steel pipe showed pinhole leaks “everywhere in the building.”
Paper-thin Pipe“From our best guess, it was from a combination of a lack of treatment of the closed loop piping system over the years, and the fiberglass insulation had been serving as a breeding ground for rust as a result of condensation,” Hammond recalled. So for two years, Westbrook tried convincing the facility owner to replace the leaking pipes and also the building’s original fancoil units (FCUs), which were installed above closets in the apartment units and difficult to access for maintenance.
Finally, in August 2008, Westbrook was contracted to install new floor-mounted FCUs and to replace all leaking schedule 80 piping with CPVC piping. Within the first few weeks of the installation, Westbrook began noticing progressively worsening leaks in the CPVC. “The first thing you think is that the guys must not have glued the fittings right, but then we saw they were glued right and that there were actually cracks in some spots,” Hammond recalled.
Westbrook discovered that the new FCUs and the water control valves contained polyolester (POE) oil, an ester-based grease commonly included in mechanical system components as a lubricant. The oil can wash out of the components and coat the inside of the CPVC pipes, causing them to crack (known as environmental stress cracking).
Since residents were displaced from their homes, the firm couldn’t halt the project, so it switched to copper piping while exploring other piping options. Hammond explained that copper wasn’t preferred because of very high prices and acidic local water conditions. However, since the closed loop system is being treated with Nalco Company additives, the copper should hold up, he said.
A Polypropylene SolutionYet, upon researching CPVC/POE oil interactions and copper pipe alternatives, Hammond was quickly convinced that polypropylene was the best option. Working with Ferguson Enterprises’ Orlando office, he learned about Aquatherm, Inc.’s polypropylene piping, which is so corrosion resistant that it’s often used in acid waste applications.
The heat fusion welding process used to join the Aquatherm pipe and fittings is so leak-proof that it is used in natural gas piping applications and has been used in more than 70 countries for over three decades.
“It was a fast-track job and once the CPVC failed, we knew that doing copper on the whole job would break the bank, so this was a phenomenal option. The product was basically impervious to anything that would be in our system,” Hammond recalled.
Following training sessions conducted by Aquatherm and Ferguson and the purchase of four Aquatherm manual welding irons, the installation began in September. Over the first few installation days the Westbrook crew familiarized themselves with heat fusion, in which the pipe and fitting are placed on an iron for a specified time (typically only seconds) then pushed together to form a homogeneous bond. However, once the crew was up and running, the process shaved several labor days off of the project, Hammond said.
Westbrook installed roughly 5,000 lineal feet of .25-in. to 1.50-in. Aquatherm Climatherm - specifically designed for HVAC applications - and thousands of fittings. With excellent rigidity and thermal expansion characteristics, the pipe also offered a natural insulation value of R-1. “Instead of 1.50-in. foamglass, we were able to use only .75-in. Armaflex insulation,” Hammond said, adding that this saved an estimated 10% to 15% on the job.
Labor Savings“Using the polypropylene made everything go super-quick - we just fused it and let it set for a few minutes, where with the CPVC we had to let the glue set for 24 hours, and that alone saved a day on the job,” Hammond said. Lake Port Square’s director of engineering, Dave Shields, added that heat fusion also saved his staff time when it came to closing up walls, carpentry, and painting.
The project concluded in January 2009, and Hammond estimated he saved 11 man days per riser - with 40 risers on the job. All parties involved are quite satisfied with the end result and the savings.