Background

There are two fresh water cooled chillers generating 400TR cooling capacity to part of a commercial building. The rest of the cooling power is provided by over 1200TR air cooled chillers.

Ordinary chemicals such as biocide, scale and corrosion inhibitor are used in the condensing water. Automatic bleed-off is set to 1500ppm of TDS. Mineral scale deposit was coated on the tubes which required annual tube cleaning to restore the cooling power.

One of the chillers was limited to run at most 75% of full load due to the scaling substance which increases the condenser approach and may trigger the high temperature cut out.

In order to improve the COP of the two chillers and restore the cooling power of them, AquaKLEAR is installed. The condenser tubes were inspected and the condition is shown in picture 1 before switching on the AquaKLEAR.

Result

After six months of operation, the condenser cover was dismantled for tube inspection. Existing scale in most area was dissolved as indicated in picture 2.

The chiller which was limited to 75% of full load is now can run at full load.

The data logged shows there is a reduction of 16.0% of energy consumption in the chiller and eventually a 2.5% - 3.0% cut in electricity bill is realized. The investment is paid back in 20 months.

An additional benefit of the installation is the improved condensing water quality with total bacteria count and Legionella count controlled well below the limit.