| Enthalpy | Amount of energy contained in a thermodynamic system (heat content) |
| FDA | Food and Drug Administration (USA) |
| Saturated steam | Boundary between wet and superheated steam; Wet steam: Parts of the gaseous water condensate to become very fine droplets Superheated steam: "Dry" steam without water droplets |
| Brine | Solution consisting of salt and water |
| Heat transfer oil/thermal oil | Heat transfer fluid on the basis of mineral oil, synthetic, organic, or on the basis of silicon, uniform or mixed |
| Water | Chemical compound consisting of oxygen (O) and hydrogen (H). Also refer to VDI 2035 for information on avoiding damage to drinking and domestic hot water plants |
| Water with antifreeze | The water contains an antifreeze which also inhibits corrosion. For the types of antifreeze used in the trade, also refer to chapter "8.1.7 Overview of antifreeze and brines used in the trade", page 89 |
| Glycol | Glycol is added to water to lower the water’s melting point. Examples are ethylene glycol and propylene glycol. Refer to chapter "8.1.7 Overview of antifreeze and brines used in the trade", page 89 |
| Water, deionized | The ions of salts contained in the water have been removed |
| Water, demineralized | The minerals contained in the water have been removed |
| Water, super-clean water | Specially treated water; various processes are used to remove dissolved salts and other undesirable substances. It has a high specific resistance and contains no organic substances |