The vast majority of households have what are known as single-lever mixers. In many cases, these are permanently set to warm or even hot. Take a look at home to see which way your lever is pointing. Setting the lever permanently to the "cold" side of the mixer helps to save hot water in everyday life. Warm water is not usually needed for washing your hands or rinsing something off quickly. Just give it a try! In principle, warm water should only be used for as short a time as absolutely necessary. Even when washing your hands, brushing your teeth, or washing your face, the water does not need to run continuously.

In principle, a full bath consumes the most hot water. Generally speaking, showers use less water than baths. However, if you leave the water running for longer than ten minutes while showering, you can actually exceed the water consumption of a bath. Hot water consumption depends heavily on personal habits. As a rule of thumb, showers should be kept as short as possible. The shower should be turned off while soaping up. By the way: taking a cold shower saves the most water, of course. You may find it easier to make the switch during the summer months.

You can determine your personal hot water consumption when showering using the shower calculator provided by the North Rhine-Westphalia Consumer Advice Center. You will find the link to the online calculator in the list of links.

Water-saving fittings can also reduce hot water costs. Water-saving shower heads, single-lever fittings, and aerators can also be retrofitted. Conventional shower heads, for example, have a flow rate of twelve to fifteen liters of water per minute. Water-saving shower heads, on the other hand, only use six to nine liters. Aerators (or perlators) also help to reduce water consumption.

The "Blue Angel" seal has added shower heads to its portfolio. The main criterion is water consumption of less than nine liters per minute, regardless of water pressure. In addition, attention was paid to durable materials. The Eco-Institut also has buying tips for shower heads on its EcoTopTen homepage. Both links can be found below.

With all these potential savings, the question naturally arises as to what temperature should be set on the water heater. When it comes to water temperature, hygiene requirements are generally the most important factor. The Drinking Water Ordinance stipulates a minimum temperature of 55°C for larger hot water tanks in apartment buildings. However, this temperature is also recommended for small systems, e.g., in single-family homes. Since our drinking water is not completely germ-free, bacteria and germs can easily multiply in stale tap water. Problematic Legionella bacteria in particular multiply very well at temperatures below 55°C. Therefore, the temperature in the water heater should not be set too low, even if this increases energy costs.

Environmental tip August 2022