top of page
AHR25_Email_Banner_400x200_for_edit.jpg

Case Studies

New Orleans Convention Center

NOCC.jpg

Operating Problem:

At the New Orleans Convention Center, Assistant Chief Engineer Charles Reed said that before 1996, fouling was visible every year when the condenser heads were opened.  HVAC mechanics manually cleaned the tubes to minimize fouling. Reed said he runs at least five chillers during the winter and usually is at full load during the summer. ''We are a 24-hr operation," Reed said. "Our exhibitors require cooling all night, 365 days a year." With an average yearly load of 5,100 hr., a 0.64-kw-per-ton rating, and power costs of 5 cents per kilowatt-hour, the operation cost of one 1,200-ton chiller was estimated at $ 234,600 per year. 

PROBLEM SOLUTION:

In 1996, the New Orleans Convention Center installed online Automatic Tube Brushing (ATB) systems manufactured by Water Technology. According to Reed, the systems eliminated the need to punch tubes and have been the key to maintaining design approach temperatures.

Once every four to six hours, the ATB system automatically reverses the water flow in the condenser for about 30 seconds. The custom-manufactured reversing valve fits into the condenser supply and return piping (Photo A). PHOTO A. A four-way-valve reverses condenser-water flow for a period of 30 seconds every six hours

Small nylon-bristled brushes with 0.025-in. interference fit shuttle through the rubes with the reversed water flow (Photo B).  Working with good chemical treatment, the brushes clean the tube walls to eliminate scale formation and fouling.

After the 30-second reverse flow, the valve returns to normal flow, once again shuttling the brushes through the tubes.  The four-way valve cycles provide 8 cleanings a day.

Open-ended, low -pressure-drop plastic catch baskets are installed in the tube ends at the tube sheet to capture the brushes in the condenser heads (Photo C). Removable end clips allow eddy­ current testing and brush replacement, which is recommended every four to five years.

Over six years, Reed's concern that some brushes might stick in the tubes has proven to be unfounded. Proper chemical treatment, correct brush sizing, and flow through the tubes of at least 4 ft per second ensure that the brushes move through the tubes when the valve cycles.

Results:

Eight chiller condensers were retrofitted, and four new chillers installed with the ATB system at the Convention Center. The estimated power costs for the 1,200-ton chiller have decreased costs about $201,200, which translates to a system payback of less than 1.5 years and yearly savings of over $33,000.

Email: watertech@atbsystems.com

Telephone: (850) 477-4789
Fax: (850) 479-3056

©2025 Water Technology of Pensacola Inc.

Water Technology of Pensacola. Inc.
3000 West Nine Mile Road
Pensacola, Florida 32534-9439

bottom of page