Bedroom on the first floor, 18 m², with a ceiling height of 2.7 m. The north-facing wall corner and the west-facing corner are damp. The property is situated on a wooded, north-facing slope.

Starting from the corner, the paint is flaking over an area extending approximately 80 cm to the west and 250 cm to the north. A reading of 60 digits was recorded using a surface moisture meter. The moisture is also visible as slight darkening of the wall, with light mould growth above the skirting boards and in the corner.

The problem occurs mainly in spring and autumn. It becomes less visible during summer and in winter, when temperatures fall below freezing and the room is heated intensively.

Three Mould-DRY modules are used: two on the north wall and one on the west wall. The modules are mounted horizontally approximately 15 cm above the floor and 10 cm from the corner. On the north wall, there is a distance of approximately 40 cm between the two modules. They operate continuously, 24 hours a day, from January to April and from September to December.

After two weeks, the moisture level in the wall begins to decrease. Capillary action draws the moisture towards the warm area behind the modules, where it evaporates. A reduction in moisture can already be measured approximately 2 m away. At a distance of around 1 m, the moisture level remains unchanged, while it is slightly higher within approximately 20 cm of the modules.

The problem has now been completely resolved. The mould growth was washed away, and the areas of flaking paint were repainted. For prevention and continued deep drying, the modules remain in continuous operation throughout the heating season. The user will test interval operation using a timer and continue to measure the wall moisture regularly. This will help determine the amount of heat required to maintain sufficient drying while using as little energy as possible.

In this case, the moisture occurs mainly during months with heavier rainfall. As the house is situated on a north-facing slope and shaded by woodland, the affected walls receive very little solar heat. Rainwater therefore takes a long time to dry and places additional strain on the foundations. Wall moisture and even more severe mould growth are also present in the ground-floor flat.

The targeted heat supplied by the Mould-DRY modules allows the moisture to evaporate slowly into the room. This can cause a slight short-term increase in humidity, which is balanced by daily ventilation.

In this case, the room temperature and humidity are not the primary cause. The main problem is moisture that has penetrated the uninsulated brick wall from outside over several years. Continuous drying during the critical seasons gradually reduces the wall moisture. After two months, the surface had dried sufficiently to prevent renewed mould growth, and the result in this room was already satisfactory.

This is an entrance porch added as an extension to a detached house. All three external walls are severely affected by mould. The room is unheated, and its external walls are built from uninsulated concrete blocks.

The mould problem returns regularly during the colder months. Washing and repainting the walls only helps during the warmer season; the mould returns when the heating season begins.

This is an entrance porch added as an extension to a detached house. All three external walls are severely affected by mould. The room is unheated, and its external walls are built from uninsulated concrete blocks.

The mould problem returns regularly during the colder months. Washing and repainting the walls only helps during the warmer season; the mould returns when the heating season begins.

The room measures only 2.5 × 1.5 m (3.75 m²) and has a ceiling height of 2.4 m. The mould growth is severe.

The customer positioned two modules on the 1.5 m wall, three modules on the 2.5 m wall and one module vertically between the corner and the front door, approximately 20 cm above the floor.

With a combined heating output of approximately 300 watts, the modules not only dry the walls directly but also provide sufficient space heating, increasing the temperature in the otherwise unheated room. As the walls become drier, the insulating properties of the highly heat-conductive concrete-block walls also improve.

After approximately three months of continuous operation, the customer began controlling the heating elements using a simple plug-in thermostat set to 19°C. Once the walls are dry enough to absorb less heat, the 300-watt heating output raises the room temperature, and the thermostat switches the elements off when the set temperature is reached.

The result is a gradual drying process through capillary action, which takes approximately one heating season from September to April.

By maintaining a higher room temperature within 5°C of the approximately 23°C temperature in the heated living areas, renewed condensation is prevented. Moisture previously entered the entrance porch whenever the connecting door to the living area was opened and then condensed on the cold walls.

To maintain the result, the entrance porch must continue to be heated from September to April. Adding external insulation to the extension could further reduce the energy required.

As the dry walls warm up more quickly and absorb less heat, the desired room temperature is reached sooner. The heating elements will therefore switch off earlier during subsequent heating seasons.

Cellar room in the corner of an older building, measuring 4.1 × 3.4 m (14 m²). The external walls are 60 cm thick and constructed from a concrete and stone mixture. The room has a concrete floor and a ceiling height of approximately 2.2 m.

There is some rising damp and significant condensation on the walls due to insufficient ventilation. Mould occurs more frequently during the warmer months, but only on the external walls.

The customer installed four modules along the longer external wall (4.1 m) and three modules along the shorter wall (3.4 m).

The mould growth is moderate. The modules operated continuously throughout the observation period from June to September, for just under four months.

Using the stands, the modules were positioned close to the walls to direct heat into the damp masonry. During the night, the narrow high-level cellar windows were opened to provide ventilation with cool fresh air. The cellar door was also left open at night to allow the rising warm air to escape upwards.

Initially, the humidity in the room increased as moisture evaporated from the wall behind the heating elements. As the wall gradually dried and its temperature increased, less moisture from the room air condensed on the cool surfaces.

After five weeks, the results were not yet significant, as cellars in older buildings can store large amounts of moisture. When the room was inspected in September, the wall temperature had reached 17°C and the relative humidity had fallen to 55%. As the humidity in this house drops below 45% during winter, the problem is less noticeable in winter than in summer.

Ventilating at night is more effective than during the day. During the daytime, the cellar can become saturated with warm, humid air. At night, the cooler temperatures allow this air to be replaced with cooler, less humid air.

A dehumidifier can provide additional support by removing moisture from the cellar air. However, ventilation is not effective on very hot and humid summer nights. In this situation, it is better to wait until the air cools or use a dehumidifier that collects the extracted water.

Heating with the Mould-DRY modules is still required to remove moisture held within the wall through capillary action.