United Nations Bangkok installation

In 2013 we installed an Elgressy EST chemical-free water treatment system on the cooling towers of the United Nations building in Bangkok. More than ten years later it is still running and is one of our main reference sites in Thailand.

The site

• Chiller plant of about 900 TR (594 kW electrical load)
• Typical operation: 10 hours a day, 300 days a year
• Design chiller approach temperature: 2.2 °C (4 °F)

What we installed

An EST side-stream system on the cooling tower loop, replacing chemical scale and corrosion treatment. The site later added an EL-CHL on-site chlorine system and, in 2025, a new SCADA remote monitoring system.

How EST works: Elgressy EST treats a side stream of the cooling water by controlled electrolysis. Calcium hardness precipitates as solid scale inside the EST reactors and is removed, instead of depositing on chiller condensers, heat exchangers and pipes. Oxidizing species formed at the anode help control algae and biofilm, so no anti-scalants or corrosion inhibitors are needed. Read more about Elgressy EST.

Results

• Lower approach temperature: one year after installation the chiller approach was 1.1 to 1.6 °C, against a design value of 2.2 °C.
• Energy savings: an estimated 3 to 5% of chiller energy, or 53,460 to 89,100 kWh and 267,300 to 445,500 Baht a year at 5 Baht per kWh. See the calculation.
• Clean water and equipment: crystal-clear cooling tower water, full flow over the fill, and piping that looked as new after 8 years of operation.

Related

• Energy cost savings 1 year after installing EST
• Chiller approach temperature before and after EST
• New SCADA monitoring at United Nations Bangkok
• All our installations in Southeast Asia

Want similar results at your site?

Water Treatment Asia (Aerial Lift Asia Co., Ltd.) has been the exclusive Elgressy distributor in Southeast Asia since 2010. Contact us for a free water analysis, a savings estimate and a visit to one of our reference sites.