It is common knowledge that it is important to save water. That is why it is common practice to turn off the water tap while brushing teeth or to turn off the shower while using shampoo or soap. But water, especially hot water, is also connected to heating energy.
A lot of daily energy use around the house comes in the form of hot water. After all, the cold water in the pipes needs to be heated before use, which takes up energy. Therefore, saving hot water while having a shower also saves heating energy. For example, many hardware stores and utilities businesses have so-called Sparduschköpfe (roughly ‘water-saving shower heads’) in stock. These devices help reduce the water flow by about the half, which saves a lot of heating energy and may prove a useful investment.
Have a shower instead of a bath
A common tip for saving water: having a quick shower uses up less water than a bath in the tub. This also applies in terms of energy efficiency: for a hot bath, about 120 litres of water need to be heated up; the average shower only needs about 50 litres. So it may save a lot of water and energy (and time!) to pass on the hot and cosy bathtub in favour of a brief shower once in a while.
Wash hands with cold water
During the covid-19 pandemic, washing the hands thoroughly has become increasingly important. However, it is a myth that only hot water can kill germs and viruses. In fact, it is more important to use a decent amount of soap while washing the hands and to take enough time to wash (with the tap turned off) and then rinse properly. This is absolutely sufficient even with cold water.
In many households in Hamburg and Germany, especially in older Altbau multi-family buildings, water is heated on demand by a boiler running on gas. Whenever the tap is opened only briefly, for washing hands, brushing teeth or filling the kettle, the boiler springs on to heat up only a small portion of water. In many cases, this hot water does not even reach the tap, but gets stuck in the pipes inside the wall. Turning the mixing battery to cold may stop the boiler from activating, preventing heat loss and gas waste.