Wash the seals with water with the addition of a mild detergent (e.g. dishwashing liquid), and then lubricate them with a suitable agent protecting against weather conditions. You can use silicone oil or ordinary cosmetic vaseline.

Regular cleaning is required because it reduces the settling of dust and dirt. To clean the uPVC window frames, you will need mild detergents, e.g. dishwashing liquid. They should not contain abrasive particles that can damage the surface of polyvinyl chloride frame.

Ventilation of rooms is even more so important as the currently commonly installed windows are very tight. This allows you to save on heating bills, but blocks the movement of air in the room. This, in turn, stops the moisture that is created when cooking, washing or using the shower. We can then observe, especially in winter, condensation of water vapor on the windows. It is in closed rooms, when the temperature and humidity are high, that microorganisms that can be harmful to us develop and proliferate.