Are Moisture and Condensation Dangerous in the Home?

    3 min

    Moisture damage is a common concern for homeowners. Improperly handled, moisture can be very harmful both to people and buildings. “Moisture itself is not dangerous, it is when the moisture is not managed that problems can occur.”

    This is what Patrik Tedsjö, CEO and head of product development at Wood’s, says.

    Moisture manifests when hot meets cold

    For property and homeowners, the importance is ensuring that moisture problems do not arise. It is of course important to ensure that a roof does not leak and that the foundation is drained and protected, but it is also about being aware that temperature differences outdoors and indoors affect and contribute to moisture. “When hot summer air enters a house and meets colder air in a basement, the moisture appears in the form of waterdrops or condensation on the walls and windows. If it is not handled promptly, or prevented, houses and people are at risk of being harmed because moisture can lead to mold,” emphasizes Tedsjö.

    Allergies, asthma, headaches, and fatigue

    If moisture is not controlled in a house, there can be unconditional mould damage to materials in the building. In addition, mould and mildew can put inhabitants’ health at risk. “Mould grows in organic materials if the conditions are right, i.e. if the temperature is above 7° Celsius and the relative humidity is above 75 percent. In addition to the damage to the home, it can lead to respiratory illnesses such as allergies and asthma, but also headaches, coughs, and fatigue,” explains Tedsjö.

    Keep track of odours, temperature, and relative humidity

    There are several ways to detect moisture and mold growth indoors. Be sure to inspect your home; for example, look for color changes on wood, note foul or strange odors, and feel free to measure humidity. “It is of course difficult to feel changes in humidity. A rule of thumb is that you should have a relative humidity of 50 percent indoors. You can measure this with the help of a simpler variant of a hygrometer. If the humidity is upwards of 70–80 percent in a basement, it is important to act. The most effective way to lower the humidity to 50 percent is to install a compressor-driven dehumidifier,” concludes Tedsjö.

    The influence of hot air – and a solution

    All indoor air is the air coming from outside. It is more or less treated or affected depending on the season. During the summer, however, few households themselves influence the indoor air because most do not heat or cool the air.

    A typical case of what happens to air during hot summer days can therefore be described as:

    • Basic condition: outdoor temperature of 25 degrees and 70 percent relative humidity.
    • When this air enters a basement or crawl space, it is strongly affected by the indoor air, it cools down.
    • If the temperature of the incoming air drops to, for example, 20 degrees, the relative humidity rises to as much as 95 percent. In both cases, there are 13.9 grams of moisture per kg of air.
    • When the temperature drops and the humidity rises, moisture falls out, which can create problems if not handled.

    The most economical and environmentally friendly way to reduce the moisture content to around 50% is to use a compressor-driven dehumidifier. With the help of a dehumidifier, the energy that the water vapour in the air carries can be efficiently recovered.