How Water Temperature Affects Laundry Results Water temperature really does affect laundry results, along with several other interacting factors which provide energy to remove soil. The three main forms of energy include: mechanical (supplied by the washer's washing action) and the amount of wash time; chemical from the detergents, bleach and other additives; and thermal from the use of warm or hot water. Creating an optimum balance of these energies provides acceptable cleaning performance. If any one of the three is decreased, the other two must be increased to maintain the same cleaning results. For example, if cold wash water is used, the thermal energy is missing. To maintain the same cleaning results, one of the other energy sources needs to be increased, such as selecting a longer wash time. However, long washing times can have negative effects. They can increase fabric wear and enhance redeposition of the soil. Warmer Water Enhances Detergent Effectiveness The energy from the water temperature not only affects the removal of soils, but it also has an effect on the chemical energy (detergent) added to the load. As the temperature of the water increases, chemical reactions (the efficiency of the detergent and other additives) proceed at a greater speed. The speed doubles with each 18 degree F. rise in temperature. If the water temperature is too cold (below 65 degrees F.), little or no chemical activation takes place. This means little or no energy comes from the detergent and cleaning performance is decreased. Plus, many granular detergents do not dissolve in cold water and will leave a powdery white residue on the load. If the temperature of water in the tub is too cold for your hands, the detergent will not activate and clean effectively. Recommended Wash Temperatures You'll get better cleaning results with hot water temperatures higher than 120 degrees F. However, if there are young children or elderly adults in the home, the water heater may be set for 120 degrees F. If the hot water temperature is 120 degrees F., in most cases the warm wash water setting will be 80 degrees F. or lower. Use a hot water (120 -140 degrees F.) wash for most white fabrics and heavily soiled colored fabrics, if they are colorfast. A warm (80-105 degrees F.) wash is the best choice for most other clothes. A cold (65-75 degrees F.) wash is recommended for very lightly soiled or brightly colored garments. Keep in mind cold water should not be lower than 65 degrees F. If the temperature is below 65 degrees F., select a warm wash water setting or partially fill with warm water and complete the fill with cold water. Use a liquid detergent when washing in cold water. Pour the detergent into the washer tub before adding the load, or into the dispenser. If using warm or cold water, add a non-chlorine bleach (like Clorox 2) for better cleaning or presoaking heavily soiled items. To save energy, always use a cold rinse. A cold rinse is just as effective as a warm one. NOTE: Temperatures below 65 degrees F. will not activate laundry additives and may cause lint, residue, poor cleaning, etc. In addition, detergent manufacturers and care labels define cold water as 80-85 degrees F.