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Home Press releases Proper ventilation saves a lot of energy.

Proper ventilation saves a lot of energy.

dena advises on how to ventilate properly in winter

As the temperatures drop, heating systems have to work harder and harder. To minimise heat loss, residents often choose not to ventilate rooms. What many people do not know: proper ventilation improves the indoor air and saves heating costs. The Deutsche Energie-Agentur GmbH (dena) – the German Energy Agency – reminds readers of this and advises on how to ventilate correctly.

Proper ventilation in every situation

In a three-person household, people, animals and house plants, as well as everyday tasks like cooking and cleaning, which release steam into the indoor air, produce roughly eight litres of water daily. In sealed rooms, moisture forms condensation on the cold walls – in a worst case scenario, this can even result in mould. Regular and proper ventilation is essential to prevent this. Proper ventilation means opening windows fully for a brief period multiple times every day. That replaces the moist air quickly and minimises energy losses. Tilting windows for ventilation, while popular, results in very slow exchanges of air. When ventilating more than one room at the same time, it makes sense to open the doors of the rooms to create a draught. However, if you are only ventilating one room, e.g. after cooking or showering, it is best to leave the door closed so that the moisture cannot spread to other rooms.

When the window is open, close the radiator valve

If the thermostat valve on the radiator is open during ventilation, you are heating the air outside. That is a waste of energy. Therefore, you should always turn off the radiator when ventilating. You should also reduce the room temperature at night.

Another tip: radiators need space. They are often hidden behind curtains or furniture. That limits the ability of a radiator to transfer heat to the room. As a result, the area around radiators should always be clear and the radiators themselves should be uncovered. Thermostat valves also should not be adjusted or hidden behind curtains - if not, heat can build up there. Thick paint layers on radiators caused by too many coats of paint can also prevent heat conduction.

For more recommendations on proper ventilation and heating, consumers can refer to the dena brochure “Machen Sie dicht: Energiesparen in Gebäuden” (Mind the gaps: saving energy in buildings) at (in German).