Many people don’t know it, but regular ventilation is the only way to ensure comfortable and healthy indoor air. The rule of thumb is: Air out rooms at least two to four times a day. But avoid leaving windows open “just a crack” all day. That’s because doing so is a major waste of energy and can cost you up to €200 more per heating season. Opening your windows all the way for a short time helps guarantee perfect indoor air and saves energy.
If your windows are old or no longer close properly, you should consider having them resealed. You can buy sealing strips for cracks and small openings in windows and doors at any hardware store. They’re self-adhesive and easy to apply. They also help prevent heat from escaping from warm rooms.
The following site
provides additional information on heating and ventilation. Follow their tips for a cozy, healthy Christmas season at home. VARTA wishes all of you happy holidays!