A small guide for dehumidification and humidification of air

Humidity in living spaces influences a wide variety of factors and is therefore of considerable relevance for a balanced indoor climate. On the one hand, the right air humidity ensures a pleasant and healthy stay in your own four walls, on the other hand, possibly occurring damage to walls and the building fabric can be prevented or at least reduced by the appropriate water content in the air. Therefore, a comfortable indoor climate is existentially important for the occupants as well as for the building fabric and deserves the appropriate attention. The following is a list of the ways in which humidity can be influenced within one’s own four walls and the consequences if it is too high or too low, i.e. the room is too dry or too humid. Often, poor indoor climate in one of the rooms is enough and it already affects the well-being. To prevent this, the following points should be considered as a guide and should be taken into account accordingly. As essential methods there are, among others, the two “setting wheels” room dehumidificationand roomhumidification.


Relative humidity is given as a percentage and indicates how much water vapor of the maximum possible vapor is currently contained in the air. In contrast, in g/m³ the absolute humidity provides information about the actual water vapor content contained in the air. Air can only absorb a certain amount of water vapor. This is significantly dependent on the temperature. Cold air can absorb less water vapor than warm air. If cold air warms up, it can absorb more and more water as the temperature increases.

Thermotec AG - A small guide for dehumidification and humidification of air - time of 2353382 1920
Thermotec AG - A small guide for dehumidification and humidification of air - time of 2353382 1920

Ventilation as the basis of humidity regulation

To ensure that a pleasant indoor climate can spread within your own four walls, regular airing is of existential importance. Without ventilation, a healthy indoor climate can not be achieved. Even modern technology, such as air purifiers or air scrubbers do not have such a benefit as fresh air from outside. The advantage of fresh air is that it does not entail costs or other negative aspects. Tip for allergy sufferers: in the meantime, there are insect screens that even keep pollen out during ventilation. Only the windows need to be opened for ventilation and one aspect of room dehumidification is already fulfilled. Even if it is raining outside and the incoming air already contains a high proportion of water, it can absorb additional water when heated in the room. Warm, humid air, on the other hand, can cause increased sweating in people, especially in summer.

RoomOptimal temperatureOptimal humidity
Living spaces & workspaces21 °C40 – 60 %
Bedroom16 – 18 °C40 – 60 %
Children room20 – 22 °C40 – 60 %
Kitchen18 – 20 °C50 – 60 %
Bathroom22 – 23 °C50 – 70 %
Basement10 – 15 °C50 – 65 %

Air in different living spaces

For example, in the bathroom, the humidity may be higher than in any other room. This is due to the water brought in by steam from the shower and bathtub, as well as from towels, which release their water into the air throughout the day by evaporation as they dry. Nevertheless, many people find a slightly increased water content in the air pleasant in the bathroom. Did you know that dust levels are particularly low in the bathroom? Especially when showering or bathing, the many water droplets settle on the dust, causing it to sink to the floor. By the way, too high humidity in the bathroom over the years makes unsuitable furniture swell from the edges, eg. simply veneered MDF chipboard. When buying bathroom furniture, pay attention to this fact.

Thermotec AG - A small guide for dehumidification and humidification of air - towel 2005042 1920
Thermotec AG - A small guide for dehumidification and humidification of air - towel 2005042 1920

The situation is different when such high humidity prevails in the bedroom or even in the living room. In this case, you would quickly start to sweat, which is perceived as unpleasant for most people. In the bedroom this can lead to sleep disturbances, in the living room too high humidity is perceived as unpleasant. In this respect, a rather low humidity is recommended, which should be lowered again and again by appropriate ventilation, even in winter.

Harmful to health and building materials

Both too high and too low humidity can have an impact on health as well as on the building fabric. Incidentally, different masonry and cladding materials, such as drywall, brick, roughcast, granite or wood, behave quite differently in terms of water absorption and release as well as water permeability. If the humidity is too high, mold can form very quickly, which on the one hand harms health, and on the other hand damages the fabric of the building. Bathrooms and kitchens are particularly at risk. However, with a few measures such as airing or using dehumidifiers if needed, the chance of mold can be significantly reduced.

How does mold actually develop? It is caused either by permanently too high humidity or by water contained in the air, which settles on cold walls during cooling. If this condensation on the wall dries too slowly or does not dry off, mold will form.

Dehumidifiers are a practical technical tool to reduce the absolute humidity inside the rooms. The dehumidifiers are used especially in old buildings or damp rooms, where there is generally a lot of water in the air. Smaller models work with a so-called Peltier element, larger variants contain a cooling circuit similar to the air conditioner installed in the car. In both cases, they work with fans, which cause some noise. Good devices filter the air to minimize the dust swirl.

Relative humidity is measured quite simply via hygrometers. For a few years now, these have also been available in digital form and in a small design for little money. Some dehumidifiers even display this value or offer a target value at which the devices switch off automatically.

Dry air in living rooms

Another problem is insufficient humidity in the air. Redness of the eyes, itchy skin but also irritation of the mucous membranes can be the result. Against this can help humidifiers in a variety of designs. They release water into the air in small quantities and provide better breathing air. Especially popular are ultrasonic humidifiers. Especially in the winter months, they provide the necessary water content in rooms that are strongly heated and thus tend to be too dry.

Optimal humidity

The listed factors indicate the importance of a balanced humidity in the rooms. Hygrometers show suboptimal humidity cheaply and quickly and you can counteract with the measures mentioned. Incidentally, small fluctuations in humidity occur in all rooms.

Just as important as healthy humidity is temperature, as it affects the air’s ability to absorb water.


A combination of healthy humidity, appropriate room temperature and ventilation of the rooms significantly affects the indoor climate. A healthy indoor climate provides better health and protects the building fabric.

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