Did you know? Warm standing water increases the number of microbes

14.4.2022Did you know?

The new Did you know series briefly presents an interesting fact or research detail. The first part deals with the quality of warm standing water in pipes.

There's three bottles on the table with sediment.

During holidays, water use in a property may be low or non-existent. In this case, the water stands still in the pipes and warms or cools down to the indoor temperature. Long periods of standing water in the pipes and changes in temperature increase the number of substances dissolved from pipe materials, precipitations, and microbes, resulting in the deterioration of the chemical and microbiological quality of the water.

The guideline is to run water at least weekly from all hot and cold water points (showers and taps) until the temperatures set in building regulations are reached. Cold water should be no more than 20 °C and hot water at least 55 °C.

For this reason, it is important to keep the temperature of the boiler at least 55 °C, even if you might want to lower the temperature to save energy. For example, the Legionella bacterium, which causes pneumonia, still survives at around 50°C and can enter the respiratory tract through water aerosols.