What does TDS stand for in evaporative cooling tower maintenance?

• A. Total Dissolved Solids
• B. Total Desolved Substances
• C. Thermal Dissolved Substances
• D. Total Drain Solids

Answer: (A)

In evaporative cooling tower maintenance, TDS refers to the amount of minerals and salts dissolved in the circulating water. These dissolved solids stay in solution rather than settling as solids, and they matter because they concentrate as water is evaporated. High TDS can cause scaling on heat transfer surfaces, reduce heat transfer efficiency, and potentially increase corrosion or fouling. That’s why operators monitor TDS and manage it by adjusting makeup water and performing blowdown to keep the dissolved solids in an acceptable range. TDS is typically inferred from conductivity measurements, since more dissolved ions make water more conductive. The correct term is Total Dissolved Solids. The other listed options aren’t standard terms used in this context (one is a misspelling, another doesn’t apply, and another uses a non-existent phrase).