Ventilation Routines for Winter Air

In winter, we seal our homes tight to keep the heat in. This is great for energy bills but terrible for air quality. CO2 rises, humidity spikes (causing condensation), and viruses linger. The solution is not to leave a window open all day—it's "Shock Ventilation".

1. What is Shock Ventilation?

Instead of leaving a window tilted open for hours (which chills the walls and wastes huge amounts of energy), you open everything wide for a short time.

• The Method: Open windows on opposite sides of the home to create a cross-draft.
• The Duration: 5 to 10 minutes. No more.
• The Result: The stale, warm air rushes out; fresh, dry air rushes in. Because the walls and furniture stay warm, the room temperature recovers within minutes after closing the windows.

2. The "3-Times-A-Day" Rule

Build this into your routine:

• Morning (The Wake-Up): Bedroom CO2 is highest when you wake up. Flush the bedrooms immediately.
• Afternoon (The Refresh): If you work from home, do this at lunch to clear brain fog.
• Evening (The Pre-Sleep): Do one last flush before bed to remove cooking smells and humidity from the day.

3. Managing Humidity

Cold outdoor air is very dry. When you bring it inside and heat it up, it becomes "thirsty" and sucks up moisture from your home. This is the #1 way to stop condensation on windows.

• Foggy Windows: This means you aren't ventilating enough.
• Dry Throats: This means you might be ventilating too much (or just heating too high). Check your hygrometer.

4. Don't Tilt! (The Kippfenster Trap)

In Europe, tilting windows ("Kippen") is common. In winter, this is a mistake.

• Why: It cools the area around the window frame aggressively, which can cause mold growth on the lintel. It provides very little air exchange compared to opening the window fully.

5. Energy Efficiency Reality Check

People fear losing heat. But humid air is harder to heat than dry air. By replacing damp indoor air with dry outdoor air, your heating system actually works more efficiently.

Summary

Be brave. Open the windows wide, freeze for 5 minutes, and enjoy fresh, warm air for the rest of the day.