Regarding Water Quality Standards
About Chilled Water
Standard for Usable Chilled Water
The recommended liquid for use in a chiller (chilled water) is clean water (see the water standard chart below), or a 30% to 40% solution industrial-use ethylene glycol. Note that if a 30% to 40% solution of industrial-use ethylene glycol is used, then there will be a reduction in cooling capacity of 10%. Alternatively, if conditioned water is used, then it should have an electrical conductivity of at least 1 µ/cm. Use of other than designated liquids can lead to product damage, liquid leakage, electrical shocks, or electrical shorts.
|Standard Item||PH（25℃）||6.8 to 8.0|
|Conductivity (µS/cm) (25 °C)||1 to 400|
|Chloride Ion (mgCI-/L)||50 or lower|
|Sulphate (mgSO42-/L)||50 or lower|
|Acid Consumption (pH 4.8) (mgCaCO3/L)||50 or lower|
|Total Hardness (mgCaCO3/L)||70 or lower|
|Calcium Hardness (mgCaCO3/L)||50 or lower|
|Silica Ion (mgSiO2/L)||30 or lower|
|Reference Components||Iron (mgFe/L)||1.0 or lower|
|Copper (mgCu/L)||1.0 or lower|
|Sulfide Ion (mgS2-/L)||Not detected|
|Ammonium Ion (mgNH4+/L)||1.0 or lower|
|Residual Chlorine (mgCI/L)||0.3 or lower|
|Free Carbon Dioxide (mgCO2/L)||4.0 or lower|
- Excerpt from JRA-GL-02-1994 of The Japan Refrigeration and Air Conditioning Industry Association
About Cooling Water
Cooling Water Choices
While underground water, tap water, or cooling towers are generally thought of as sources of cooling water for water-cooled condensers, the water quality standards listed below should be carefully considered when choosing the water source.
Water Quality Standard Guidelines
The following water quality standard should be used as a guideline for primary cooling water (water for water cooled condensers in refrigeration equipment, constant-temperature circulating water in water temperature controllers, or conditioned water used for heating).
Water Quality Standard for Primary Cooling Water
- If tap water is used as the primary cooling water for water cooled equipment, then the water should meet the following water quality standard.
- Within the "Tendency toward" column, items marked with a ○ indicate this component can lead to corrosion or scaling as indicated.
- The 15 items listed below are the primary components that can lead to corrosion or scaling.
|Item||Cooling Water System||Has Tendency Towards:|
|Circulating water||Make-up Water||Corrosion||Scaling|
|Standard Item||PH（25℃）||6.5 - 8.2||6.0 - 8.0||○||○|
|Conductivity (µS/cm) (25 °C)||800 or lower||300 or lower||○||○|
|Chloride Ion (mgCI-/L)||200 or lower||50 or lower||○|
|Sulphate (mgSO42-/L)||200 or lower||50 or lower||○|
|Acid Consumption (pH 4.8) (mgCaCO3/L)||100 or lower||50 or lower||○|
|Total Hardness (mgCaCO3/L)||200 or lower||70 or lower||○|
|Calcium Hardness (mgCaCO3/L)||150 or lower||50 or lower||○|
|Silica Ion (mgSiO2/L)||50 or lower||30 or lower||○|
|Reference Components||Iron (mgFe/L)||1.0 or lower||0.3 or lower||○||○|
|Copper (mgCu/L)||0.3 or lower||0.1 or lower||○|
|Sulfide Ion (mgS2-/L)||Not detected||Not detected||○|
|Ammonium Ion (mgNH4+/L)||1.0 or lower||0.1 or lower||○|
|Residual Chlorine (mgCI/L)||0.3 or lower||0.3 or lower||○|
|Free Carbon Dioxide (mgCO2/L)||4.0 or lower||4.0 or lower||○|
|Ryznar Stability Index||6.0 to 7.0||-||○||○|