The Humidity and Moisture Trap
When it pours outside, we bolt our windows and doors. While this keeps the rain out, it also traps moisture inside. Everyday activities like cooking, bathing, and even breathing release water vapour into the air. Without ventilation, this moisture has
nowhere to go. During the monsoon, outdoor humidity is already high, and when trapped indoors, relative humidity levels can soar to 80-90%. An ideal indoor humidity level is between 30-50%. Anything higher creates a stuffy, uncomfortable environment and sets the stage for more serious problems affecting both your home and your health.
An Open Invitation for Mould and Mildew
High humidity is the single most important factor for mould growth. These microscopic fungi thrive in damp, poorly ventilated spaces, finding a home on walls, behind furniture, in closets, and even in air conditioner ducts. As mould grows, it releases tiny spores into the air. Inhaling these spores can trigger a range of health issues, including coughing, sneezing, eye irritation, skin rashes, and worsening symptoms for those with asthma or allergies. That musty smell you often notice during the rains is a tell-tale sign that mould might be an uninvited guest in your home.
The Pollutant Soup Inside Your Home
It’s not just about mould. A closed-up home concentrates a cocktail of other indoor pollutants. Volatile Organic Compounds (VOCs) are gases emitted from common household items like paints, cleaning supplies, furniture, and air fresheners. High humidity and warm temperatures can actually accelerate the release of these chemicals. With no fresh air to dilute them, VOCs can accumulate to levels that cause headaches, dizziness, and irritation of the eyes, nose and throat. Furthermore, dust mites, another common allergen, flourish in damp textiles like carpets, curtains, and bedding, further degrading the quality of the air you breathe indoors.
Smart Ventilation Is Your Best Defence
The solution isn't to leave your windows open to the pouring rain, but to ventilate strategically. Seize opportunities when it's not raining, or when outdoor humidity feels lower, to open windows and doors for at least 15-20 minutes a day. This practice, known as a 'shock ventilation', allows stale, polluted indoor air to escape and fresh air to circulate. Always use exhaust fans in kitchens while cooking and in bathrooms after a shower to expel moisture-laden air directly outside. If you have fans in multiple rooms, creating cross-ventilation can significantly improve airflow without needing to keep windows open for long.
Actively Control Indoor Moisture
Beyond ventilation, take active steps to manage dampness. If you notice condensation on windows or walls, wipe it away promptly. Check for and repair any leaks in your roof or plumbing that could be letting water in. For homes in particularly humid regions, investing in a dehumidifier can be a game-changer, helping to maintain a healthy humidity level between 30-50%. Simple habits, like avoiding drying clothes indoors and ensuring your air conditioner filters are clean, can also make a significant difference in preventing moisture buildup.
