Overview
- Authorities and consumer advisers now recommend short, full-window 'stoßlüften' rather than tilted windows, with typical winter durations of about 3–5 minutes and milder-season guidance of 5–10 or 10–20 minutes depending on conditions.
- Measure before you act: use a thermo-hygrometer to keep living spaces near 40–60% relative humidity and an infrared thermometer to spot cold surface points that can trigger local condensation.
- DIN 4108-2 provides a diagnostic benchmark under its test conditions: an exposed surface temperature near 12.6 °C (with 20 °C inside and −5 °C outside) suggests a potential thermal bridge that needs technical assessment.
- Electric dehumidifiers can lower persistent room humidity but do not fix cold walls or heat-bridges and carry energy costs that vary by device and use, so they should be a supplemental measure after trying heating, ventilation, and measurement.
- Simple habits protect homes and people: heat rooms to recommended ranges, ventilate after sleep, cooking and showers with the bathroom door closed when windows are present, keep furniture 5–10 cm from exterior walls, and treat older or poorly insulated buildings as higher risk that may require structural fixes.