The Hidden Flood of Moisture
It might not look like much, but a single load of wet washing can release an astonishing amount of water into your home’s atmosphere—nearly two litres, according to experts. When you hang these clothes in a closed, unventilated room, that water has nowhere
to go. It turns into water vapour, dramatically increasing the humidity level in the room by up to 30%. This creates a warm, damp environment that is the perfect petri dish for mould and mildew, which can begin to grow on walls, ceilings, and around windows. This excess moisture doesn't just stay in one spot; it can also cause long-term damage like peeling paint and warped wooden furniture.
A Breeding Ground for Harmful Mould
The most significant health concern from indoor drying is the growth of mould spores. One particular fungus, Aspergillus fumigatus, thrives in these damp conditions. While most healthy people can fight off the spores, they pose a serious threat to those with asthma or weakened immune systems, such as cancer patients or individuals with autoimmune diseases. Inhaling these spores can trigger allergic reactions, cause coughing and wheezing, and in severe cases, lead to a lung infection called pulmonary aspergillosis, which can cause irreparable damage to the lungs and sinuses. Studies show that occupants of damp or mouldy homes have a significantly higher risk of respiratory symptoms and asthma.
It's Not Just Water in the Air
The moisture from your clothes isn't the only thing being released into the air. Many laundry detergents and fabric softeners contain fragrances and chemicals known as volatile organic compounds (VOCs). When clothes dry, these chemicals evaporate into your living space. Studies have found that scented laundry products can emit dozens of VOCs, including some classified as hazardous air pollutants like benzene and acetaldehyde, which are considered carcinogens. Inhaling these chemicals can contribute to poor indoor air quality and may lead to headaches, dizziness, and respiratory irritation over time, especially in poorly ventilated areas.
The Musty Smell Is a Warning Sign
If you've noticed that clothes dried indoors sometimes have a distinct musty or damp smell, that's a clear signal of a problem. That odour is caused by bacteria, such as Moraxella osloensis, multiplying in the fabric because it has remained damp for too long. The faster your laundry dries, the less likely it is that these odour-causing bacteria will have a chance to grow. This smell is not just unpleasant; it's an indicator that your drying environment is too humid and stagnant, which also encourages mould growth.
Smarter Ways to Dry Clothes Indoors
While drying clothes outside is always the best option, it's not always practical. If you must dry laundry inside, ventilation is key. Always crack open a window or door in the room where the clothes are hanging. Spreading clothes out as much as possible on a drying rack, rather than overcrowding them, allows air to circulate more freely and speeds up drying. For better results, place a dehumidifier in the room to pull excess moisture from the air. Using an extra spin cycle on your washing machine can also help by removing more water before you even hang the clothes. Avoid drying clothes in main living areas or bedrooms; a bathroom with an exhaust fan is a much better choice.
