Dewpoint and mould-critical temperature
When the relative humidity reaches the threshold value of 100 % excess moisture starts to condense and forms condensation water. The temperature at which condensation occurs is called the dewpoint. As the relative humidity is a function of the air temperature the dewpoint varies depending on the respective situation. For example, the dewpoint at a room temperature of 20 °C, with a relative humidity of 50 %, is 9.3 °C.
We know today that mould can already start to grow at a room humidity of 80 %. This means that in the given example, mould can start to grow at a surface temperature of 12.6 °C or less on walls, especially in corners and niches.
As already mentioned, humidity can be regulated by correct ventilation behaviour and kept at a pleasant level. Due to modern building standards and growing requirements for energy efficiency in new buildings, more and more importance is being attached to the topic of living area ventilation. As from 2009, for example, the ventilation standard DIN 1946-6 stipulates the preparation of a ventilation concept that ensures a minimum air exchange rate in new buildings or major refurbishment projects.
You will find more information on this topic on our Info Page on the DIN 1946-6 or on the internet at www.wohnungslueftung-ev.de.
Our local Deceuninck partners will gladly assist you and give you advice on the spot in connection with new buildings or renovation projects!