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Basement ventilation in summer

How do I ventilate the cellar properly in summer?

High temperatures and stuffy air in summer increase our need to open the windows often and for a long time to get fresh air into the house. But is this also the best way to ventilate? Basements in particular are sensitive areas that are often prone to mould growth. Due to their location in the ground, they are usually the coolest rooms in a house. However, low temperatures bring high humidity, which in turn can lead to damp walls and thus mould. There is a widespread belief that rooms should be ventilated a lot in summer to dry them out, but this is a misconception. We will tell you more about this in our seven tips for airing in summer.


6 tips for airing in summer

Warm air carries more moisture than cold air, so you should not ventilate on hot summer days. The humidity then settles as condensation on the walls.


Anyone who uses the cellar as a living space should ventilate it two to four times a day. About twelve litres of water accumulate in a house where 4 people live.


Short bursts of airing (wide opened window) for five to ten minutes instead of continuous airing with a tilted window proves to be more effective. On the one hand, opening the entire window allows the air to be exchanged more effectively, and on the other hand, less energy is wasted in winter.


With a hygrometer you can check how high the humidity is in the basement. You should always ventilate when the absolute humidity outside is lower than in the basement.


In summer, the optimal time to ventilate is early in the morning or alternatively at night, as outside temperatures are lower at these times.


To ensure that the air can circulate well and also reach the outside walls, furniture should be placed at an appropriate distance from the wall.


Why do I need to ventilate?

Many harmful pollutants accumulate in the air in living spaces, consisting of dust and other small materials. Dust is a collective term for fine particles suspended in the air and includes, among other things, the remains of organic particles from people, fibres from fabrics, fine dust or living and dead bacteria. Small materials are, for example, building materials such as concrete, wood or insulation materials. This combination of fine particles damages the organism of the human body. Moisture, which is not only produced by breathing, but also increases considerably when showering or cooking, is also absorbed into the warm air and leads to a deterioration of the indoor air. The warmer the room air is, the more moisture it can absorb. This makes cool rooms more susceptible to mould.

According to the Federal Environment Agency, the ideal temperature in living rooms is between 18 and 22 degrees. Even when you are away, the room temperature should not drop below 16 degrees. Ideally, all rooms should have a similar temperature. If there are differences of more than five degrees, it is best to keep the doors between the rooms closed. Ventilation replaces stale air with excessively high CO2 concentrations, humidity and pollutants with fresh air. In living rooms, this prevents fatigue and impaired concentration in the people who spend time there. In storage and cellar areas, the formation of mould and damage to stored goods is prevented.

6 tips for airing in winter

In turn, low temperatures increase the humidity. That is why basement rooms are particularly susceptible to mould growth - especially in winter. To counteract this, we have summarised 6 tips for ventilation in winter for you.

Go to the tips for winter

Maintaining ACO cellar windows correctly

Only use mild, ph-neutral cleaning agents in diluted form for cleaning!

Never use sharp objects, scouring agents or aggressive cleaning agents (e.g. cleaning agents containing vinegar or acid), as these can attack the corrosion protection of the fittings! When cleaning, make sure that no water runs into the fitting. After cleaning, dry the hardware thoroughly and lightly oil the surface with an acid- and resin-free oil by wiping it with an oil-soaked cloth.

Your windows/window doors are equipped with a high-quality SIEGENIA fitting. In order to maintain its smooth running and perfect function for as long as possible, we recommend that you carry out the maintenance and inspection work described below at regular intervals (at least once a year or more frequently, or every six months in school and hotel buildings, near the sea or in areas where drifting sand is to be expected).

Grease or oil all moving hardware parts and all locking points. Use only acid- and resin-free oil or grease for this purpose. For the moving parts in the window sash, a spray grease is advantageous, which you spray into each opening of the fitting. Then move the hardware several times to the intended switching positions until the grease is distributed. Wipe off excess oil/grease from the window frame. Then grease the striking plates in the window frame with a stiffer grease (consistency class 2 according to DIN 51818) at the points where the locking pin engages in the striking plate. Our maintenance grease, which you can order from SIEGENIA under the material number ZXSXO 120-093010, is particularly suitable for this purpose.