Overview
- Utilities and consumer advisors stress switching radiators off during airing, noting thermostats otherwise try to reheat rooms and effectively waste energy through open windows.
- Incorrect airing can raise annual heating bills by up to about 10%, according to guidance citing Stadtwerke München.
- Seasonal timings are key: in winter air rooms for roughly 3–10 minutes, in spring and autumn 10–20 minutes, and in summer 20–30 minutes, with cross-ventilation preferred over tilted windows.
- Frequency guidance calls for multiple sessions daily—at least morning and evening if away, with extra airing after cooking or showering—and a winter 5x5 rule (five times for five minutes) or 3x5 when schedules are tight.
- Morning bedroom routines include ‘double ventilation’: air once with heat off, warm the room briefly to draw moisture from bedding, then air a second time, while keeping rooms around or above 16°C to curb condensation; people release roughly 6–12 liters of moisture per day, so a hygrometer over 60% signals it’s time to ventilate.