1. Why airing is important in freezing temperatures
The air outside may be cold, but it is also dry. The air inside is often oversaturated with moisture due to:
- Showing and bathing
- Cooking
- Washing and drying
- Even breathing (two people produce up to 10 litres of moisture a day!)
When warm, humid indoor air comes into contact with cold walls and windows, this moisture condenses - the perfect breeding ground for mould and dust mites. By ventilating briefly and vigorously with the dry outside air, you reduce indoor humidity, creating a healthier climate as well as saving energy (dry air heats up faster than humid air).
2. The myth of keeping a window tilted
Do not leave your windows not ajar ('on kip') all day. This is the most inefficient and energy-wasting way of ventilating:
- It slowly but surely cools down your walls and furniture.
- The fresh air flow is too weak to really replace polluted air.
- You are unnecessarily heating up your energy bill.
3. The golden rule: brief and vigorous ventilation
Use the 'bump ventilation' technique, the gold standard for winter:
- Time: 5 to 10 minutes maximum.
- Method: Fully open two opposite windows or doors (draught or bathroom/kitchen).
- Effect: This creates a strong, fast airflow that at once replaces the 'old' humid air with dry outside air.
Your furniture and walls retain their heat (mass), so the new, dry air quickly returns to temperature as soon as you close the windows.
4. Focus on humid areas (kitchen & bathroom)
Even if you ventilate the rest of the house less, the kitchen and bathroom are the absolute priority.
- Bathroom: After every shower or bath, open the window (and door) briefly to release the steam and moisture immediately.
- Kitchen: Use the extractor hood during cooking and ventilate briefly after preparing meals.
Extra tip from TRIXXO: Did you know that your household helper can help you with weekly maintenance of damp areas to prevent mould? Think about cleaning joints and shower screens.
5. The difference between ventilating and venting
Although the terms are often used interchangeably, there is an important difference:
- Ventilating: The continuous refreshing of a small amount of air (24/7), often through vents or a mechanical ventilation system. You always keep this on.
- Ventilation: Opening windows and doors briefly and forcefully to change a lot of air at once.
Conclusion: Keep your vents always open (ventilate) and use bump ventilation (ventilate) once or twice a day - even when it is freezing.