Using polypropylene-random pipe for snow melt, radiant applications
Snow melt, radiant and so much more.
Providing radiant floor heating, these manifolds were created by simply drilling into the 1 1/2 in. SDR 11 Aquatherm Blue Pipe and using heat fusion outlets to connect to the company's radiant tubing product. Since the fusion outlets are connected to the outside of the pipe, they do not affect flow rates. With no mechanical joint, the connection is nearly leak-proof. Photo credit: Aquatherm
Aquatherm Blue Pipe half-inch coiled tubing was used for the radiant floor heating system at the Billion Auto Group in Bozeman, Mont. The tubing possesses flow rates similar to three-quarter-inch PEX tubing. While the pipe used for this installation didn’t have an oxygen barrier, the system does use rust inhibitors to protect the ferrous metals contained in it. Photo credit: Aquatherm
When the owners of the Billion Auto Group in Bozeman, Mont., were planning a new three-building auto plaza (Chrysler, GMC and Nissan), polypropylene-random piping system was slated for a simple boiler hookup, while steel pipe was specified for chemical uses and copper was to be used for other water uses.
However, the project’s plumbing contractor, Phil Egbert, president of Egbert Electric and Plumbing (also in Bozeman), suggested that, instead of multiple piping materials, installing PP-R pipe — which is durable, chemically inert and corrosion-proof — for the entire project would save time and money.
The 60,000-sq.-ft. complex features show floors and car lots, two service departments, a body shop, a self-service carwash and a custom detail shop. With all these areas needing a large amount of pipe, the project’s designers sought a single type of piping that could be used for:
• Domestic water;
• Snow melt;
• Propylene-glycol radiant floor heating;
• Compressed-air tools;
• Ethylene glycol (anti-freeze);
• New motor oil;
• Waste oil from service bays to waste-oil boiler storage;
• Automatic transmission fluid;
• Methanol for windshield washer fluid; and
• Compressed nitrogen to charge tires.
“It is somewhat unprecedented for PP-R to be used for motor oil, transmission fluid, wiper fluid, etc., but the material can handle a lot of chemicals,” notes Barry Campbell, Aquatherm’s vice president of advertising and media relations.
“The actual behavior of any piping system when exposed to a specific chemical is extremely dependent on the exposure conditions (such as temperature, pressure, flow and duration), the stresses on the piping material and system (such as mechanical, thermal and cyclic), and the ancillary materials in the system (such as O-rings, seals, gaskets and metal components),” he adds.
Because of these factors, the company evaluates each installation for chemical applications on a case-by-case basis and approved usage of the pipe system.
Egbert showed the dealership owners the upfront cost and labor savings that could be realized with a PP-R piping system. While steel and copper markets can be volatile, PP-R prices are quite stable and typically lower than traditional metal piping options when the total cost of the job is considered.
The original bid from Egbert for the plumbing system using copper and stainless steel was $260,000. By substituting PP-R pipe and integrating other design changes, the bid dropped to $180,000. Additionally, the original $180,000 heating bid dropped to $102,000.
“A lot of changes on the job resulted in pretty large savings, and Aquatherm definitely played a big role in that,” Egbert notes.
Egbert and David Morrell, president of Bozeman-based manufacturers rep firm Ridgeline Mechanical Sales, worked together on the snow-melt design for layout, piping and controls. Ridgeline, which has a reputation for detailed product knowledge and support, provided extensive details about the PP-R piping systems.
Changes from the original design regarding piping for water and the various chemicals were coordinated between Egbert, the project engineer and the other contractor as a value-engineering design, Morrell notes.
Other equipment used on the project include Honeywell pumps, controls, air eliminators and thermostats; Fernox boiler-treatment chemicals; and Supreme Heat boilers.
Heat fusion
The dealership owners were very interested in Aquatherm’s unique welding process. “They liked the fusion aspect,” Morrell says. “The benefit of no mechanical joints, especially with glycol, was huge.”
Heat-fusion welding bonds both parts of a joint into a single, homogenous material without the use of chemicals or mechanical connections, which eliminates systematic weaknesses and fail-points in the pipe. The heat-fusion joints maintain the same properties as the pipe itself, so physical stresses will not damage their integrity or cause leaks. And fewer leaks mean lower maintenance costs.
Egbert owned the fusion-welding equipment needed for the PP-R pipe. His crew was already trained on the heat-fusion process, so no time was wasted when constructing the piping systems at the dealership.
Egbert used about 100,000 ft. of Aquatherm PP-R pipe from 1/2 in. to 4 in. for the three-building auto plaza. Blue Pipe — specially engineered for hydronic, geothermal and industrial applications — was used for the chemical applications. For the project’s potable water requirements, Green Pipe — a pressure pipe system designed for potable use but offering a tremendous range of uses — was selected.
The walls of PP-R piping systems generate less friction than other systems, eliminating abrasion that can cause pin-holing and shorten the lifecycle of the pipe, the company says.
Going green
The dealership owners not only wanted an economical and durable piping system, they also wanted a system that is good for the environment. “Billion Auto Group is very environmentally responsible,” Morrell says. “This was a way for us to provide a good product that also was green.”
From raw material to installed end product, Aquatherm PP-R piping systems require less energy to produce than comparable alternatives. Additionally, the systems are chemically inert and the fusion connections contain no foreign materials, so the piping will not gradually contaminate its source water. Reduced head loss within the pipe also helps save energy throughout the system’s life cycle.
And with heat fusion, leaks are all but eliminated, saving water and other fluids.
Once the piping was installed, the dealership owners were impressed that the boiler room didn’t feel like a sauna. “The boiler room is much cooler because PP-R pipe doesn’t give off heat like copper would,” Morrell explains.
When all was said and done, the owners got exactly what they wanted: a cost-efficient, comfortable and environmentally responsible car dealership and service plaza that attracts customers year-round. With two years of the systems in full operation under their belt, the Billion maintenance staff reports the systems have performed flawlessly.
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