BACKGROUND

The OHSU Center for Health & Healing, a LEED Platinum medical office building in the Pacific Northwest,* utilizes a membrane bioreactor to treat waste water from the building. Treated water from the bioreactor is used as cooling tower make-up.

During hot weather, the needed blowdown rate of the tower exceeds the input capacity of the bioreactor, which can treat up to 35,000 gallons per day. To avoid exceeding capacity, the blowdown rate was reduced, leading the tower to increase cycles of concentration as high as 8. These high cycles, combined with the difficult water quality, resulted in scaled chillers that required acid cleaning.

New Nalco Technology Significantly Improves Chiller Cleanliness at CBRE RIMCO Portland

CH-1712

CASE STUDY – INSTITUTIONAL

PROPOSED SOLUTIONA water analysis and equipment evaluation was conducted in cooperation with the Portand State University's Civil and Environmental Engineering Department. Following a careful study of the challenges faced, which included effectiveness, equipment size, energy efficiency, serviceability, capital requirements, operating costs and waste disposal needs, the engineering team along with a select group of university undergraduates, determined that Nalco’s 3D TRASAR™ Water Saver™ Technology was the optimal solution. The 3D TRASAR Water Saver program, Nalco’s newest water treatment technology, is a comprehensive program that includes on-line water conditioning, Nalco chemistry, service, and 24/7 monitoring via Nalco’s patented

(Continued on Reverse Side)

*At its opening, the Oregon Health & Science University (OHSU) Center for Health & Healing is one of the largest LEED Platinum projects in the nation and the first medical facility in the world to be built to this standard. (http://www.ohsu.edu/xd/about/visiting/locations/chh.cfm). This site is currently managed and operated by a team from CBRE Global Corporate Services.

Parameter Before WS After WS Savings

Scale/corrosion inhibitor usage (lb/yr) 435 138 297

Acid (lb/yr) Not used Not used --

Tower biocide No change No change --

3D TRASAR Technology. This program can reduce cooling tower blowdown water loss by up to 80% and the chemical use footprint by 50% or more, while maintaining chiller efficiency.

RESULTS

The 3D TRASAR Water Saver system was installed and operated for the entire 2013 cooling season. As a result, the cooling tower ran at an average of seven cycles of concentration.

Chiller inspection showed substantial improvement in chiller cleanliness, eliminating the need for acid cleaning of the tubes.

Corrosion rates for mild steel were maintained below 1.8 mpy; corrosion rates for copper were maintained at 0.1 mpy. Control of microbiological growth was achieved with no increase in biocide feed.

The system has bag filtration to capture particulates in the cooling water. Filter bag changes were reduced by using the 3D TRASAR Water Saver system. The new equipment preferentially captures precipitated calcium and silica.

VISUAL EVIDENCE

Chiller 2 (Small chiller) tubes after 2012 season (system was acid cleaned to remove deposits).

Chiller 2 after Acid Cleaning - 2012

Chiller 2013 – No Acid Cleaning

Tower Basin – 2013Tower Basin – 2012

3D TRASAR, Water Saver, Ecolab, NALCO and the logos are Trademarks of Ecolab USA Inc.©2014 Ecolab USA Inc. All Rights Reserved 10-14

Nalco, an Ecolab CompanyNorth America: Headquarters – 1601 West Diehl Road • Naperville, Illinois 60563 • USA Nalco Champion – 7705 Highway 90-A • Sugar Land, Texas 77478 • USAEurope: Richtistrasse 7 • 8304 Wallisellen • SwitzerlandAsia Pacific: 2 International Business Park • #02-20 The Strategy Tower 2 • Singapore 609930Latin America: Av. das Nações Unidas 17.891 • 6° andar • São Paulo • SP • Brazil • CEP 04795-100

www.nalco.com