ACHRNEWS

Rehabilitation of Chiller Piping System Saves Energy and Water

May 16, 2011

Over time, piping systems reach their expected useful life and require replacement to avoid failure. However, replacement isn’t always an optimal solution for aging systems, especially when pipes are located within or beneath a building. Using a patented epoxy coating, Nu Flow can rehabilitate pipe systems with a non-invasive process, avoiding destruction to the building.

Project: Pull structural liner spot repairs in place to seal existing holes before lining chiller system main, risers, and returns using Nu Flow’s epoxy coating.

Customer: St. Croix Club, Naples, Fla., a condominium complex with association on the Gulf of Mexico.

Site: Three six-story beachfront mid-rise buildings, each with 12 units built in 1972.

System: A chiller main consisting of approximately 800 feet of 6-inch galvanized pipe, 420 feet of 4-inch galvanized risers with returns and connections in each of the 36 rooms.

Situation: The chiller system was experiencing degraded performance and leaks due to hard mineral build-up, corrosion, and reduced diameter. When St. Croix realized the system was working inefficiently, several system improvements were made including replacing the 15 hp pump with a 25 hp pump in a failed attempt to improve water flow through the pipes.

According to the project engineer, Bill VanRite, pressure gauges on the system indicated the real problem. The pressure on the supply and return lines should be about equal; however, there was a significant difference (42 psi on the supply side and 19 psi on the return). After completing a camera inspection, it was clear the problem was in the pipes.

Solution: Nu Flow’s solution saved the customer from the cost and logistics of repairing and replacing the piping system by using existing connections to rehabilitate the pipes in place. First, Nu Flow removed any buildup and corrosion using waterless technology. Spot repairs were then pulled into place to seal any holes in the system. Once complete, Nu Flow applied an evenly coated layer of its epoxy to stop corrosion and prevent future leaks.

VanRite downsized the pump back to an appropriate 15 hp pump and the system was working again. Given that the 25 hp pump with estimated motor efficiency of 90 percent was replaced by a 15 hp pump with a 96 percent motor efficiency, St. Croix now saves over $7,000 per year in electricity costs not to mention the cost of the water to constantly replace what was leaking from the system.

For more information, visit www.nuflowtech.com.

Publication date: 05/16/2011