Overview
- Consumer advisers and the federal consumer ministry reiterate shock or cross-ventilation as the standard in cold months, especially after showering or cooking.
- Use a hygrometer to time ventilation and keep indoor humidity around 40–60% to reduce mold risk.
- Keep doors to unheated rooms closed except during cross-ventilation to prevent moist air spreading.
- Avoid drying laundry indoors to limit moisture that can fuel mold growth.
- Short, regular airing—about three to five minutes several times daily—helps protect health and building fabric without unnecessary heat loss when radiators are switched off.