Cool the apartment down

At record temperatures of up to 40 degrees, it gets stuffy warm in the building. In addition to the technical investments, numerous household tips also help.

Due to today’s building constructions, insulation and construction methods, there are many prerequisites for a pleasant climate, but the stay can still feel like in a sauna. After all, the factors of people, equipment, sunlight and humidity still play an important role. We show you how to keep your home cool despite the prolonged heat.

Proper ventilation at high temperatures and high humidity

Many people are of the opinion that a tilted window provides an exchange of fresh and, above all, cool air from outside throughout the day. However, the cool breeze that many enjoy so much is also a source of humid air, which can accumulate directly above the tilted window and at the window recesses, especially in summer. This favours the formation of mould, which can develop unnoticed over many months.

Inside the house or apartment, the air in the room is warmed up by many activities and supplied with moisture. This includes cooking and preparing food, personal hygiene and evaporation, indoor plants and washing laundry. With four people in the house, up to 10 litres of water can be released as room air. If there are very cool corners in the house, this is a guarantee for the mould formation with insufficient ventilation.

50 percent humidity means that the air has absorbed half the amount of water vapour that is possible. At 100 percent, the air is completely saturated with water vapour. If further moisture is added, condensation can be seen on walls and windows. This can already occur if apartments and rooms are poorly insulated or if different temperatures are present.

The ideal air humidity is 40 to 60 percent at 20 to 23 degrees.

In summer in particular, air should be blown in because the humidity is increased in the summer months. For this reason, ventilation should be provided for at least 25 to 30 minutes in order to enable a complete replacement of the used air. Due to the warm temperatures and the high humidity, the exchange does not take place as quickly as in the cold winter months.

Since the heat can accumulate very strongly in summer, it is advisable to ventilate only in the early morning and late evening hours or to leave the window open overnight if cooling is announced. The cool air can thus be stored longer inside and does not heat up together with the outside air. Opening all doors and windows at the same time helps in the evenings and mornings to provide a refreshing draught that lets the apartment cool down further.

The cool cellar should not be ventilated by house owners in summer at hot temperatures, because the warm outside air condenses on the cold walls of the cellar and promotes the breeding ground for mould.

Adjusting the air conditioning correctly

Anyone who has purchased an air conditioning system in their office or home will be delighted by the cool air inside. However, caution is advised here, as incorrect settings can cause both the home and the occupants to suffer from the system.

The air conditioning system works in principle like a refrigerator, because a refrigerant is circulating in a closed circuit. The heat of the room is absorbed and released to the outside.

Particularly in offices, in many apartments and rooms under the roof or with large window sections, the air can heat up very strongly. An air conditioning system ensures a constant, pleasant temperature if the settings are correct.

However, it is recommended to use settings that keep the temperature no more than six degrees lower than the existing outside temperature. The ideal temperature for most people to feel comfortable in is between 20 and 25 degrees, but when the outside temperature is 30 degrees, people can freeze when the inside temperature is below 25 degrees. The cool breeze can also cause muscle tension if it is too cold.

Therefore, the air flow in the room should be dynamic and in motion and an intelligent cooling system should be available. Since cold air is less able to absorb moisture, dehumidifying the air makes sense. Many air conditioners contain this function and therefore also exchange the air.

Targeted use of fans

Many people are tied to the office or the workplace during the day and air conditioners or cellar rooms are not available to them everywhere. Fans are one way of cooling people and ensuring a pleasant indoor climate. There are different models and sizes that can be used depending on the room and preference. Most fans deliver around 25 watts of heat output at the highest level, and only three watts at the lowest. They cool the body by draught over the skin, facilitate perspiration and evaporative cooling.
However, energy-saving fans are already available:

Summer fans are designed to provide a fresh breeze with maximum performance in summer. A distinction can be made between ceiling fans, floor fans, tower fans and table fans.

The floor fans need a high performance and can produce up to 5000 cubic metres of air per hour.

Table and tower fans should be placed suitably in the room and should only reach the occupants directly for a short cool down. Ideally, the units should be positioned at a distance of 180 to 200 centimeters. There are even more tips in our summer fan guide.

Ceiling fans are versatile and can be used in winter and summer. In winter, they turn to the left to mix the warm air from the ceiling with the cold air from the floor. In the summer, the fans turn to the right, because this presses the air against the ceiling and creates an air flow that has a pleasantly cooling effect.

The fans should be selected according to the size and height of the room, because the smaller the diameter, the faster the fan can move and the steeper the angle of the blades, the more air is carried over them.

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