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How to minimize condensation in your home




Condensation - fogged windows are the worst! Condensation makes it difficult to look out of the windows and worse - it can damage the building's condition and interior. If left long enough, it can develop into mold, which is harmful to you and your health. If you notice condensation, remove it with a cloth. But fortunately there are also ways to minimize the formation of condensation.


Why does condensation occur?

Condensation occurs when warm air meets a cold surface in a room with high humidity. Therefore, it frequently occurs in the winter months, when the radiator is at full blast and the warm air in the room hits the cold windows. But it is the humidity that you need to pay attention to, because you can control it. The humidity is therefore the key to minimizing condensation and thus achieving a good indoor climate.


So what is an appropriate humidity level?

The recommended humidity level in a home is 30-60%. In winter, preferably at the lower end, i.e. 30-45%. Humidity is measured with a hygrometer, which is an incorporated function in several thermometers.


What determines the humidity?

The biggest source of moisture indoors is the residents and what they do in the house. A typical family produces around 10 liters of moisture per day. It is often the bathroom and the kitchen that are the biggest culprits, where cooking, coffee brewing and hot showers generate large amounts of moisture - in addition to general breathing, but please don´t try to regulate that part 😉


Ventilation and venting

In order to keep the air humidity at a suitable level, it is therefore essential to have good ventilation and regular airing. Be sure to use the hood when you are in the kitchen and be sure to turn on the ventilation in the bathroom.

In rooms without windows or in modern buildings with good window constructions, less air gets in. Therefore, you should pay particular attention to good ventilation and possibly use forced ventilation in these areas. A ventilation rate of 0.35 l/s per m2 is sufficient here. This is equivalent to replacing the air in the room every two hours.


Plan 11 a

Radiators and condensation

Many radiators today work by means of convection heat. In short, convection heat heats the air in a room. This has a big impact on why radiators are usually placed under a window or in front of large glass sections as cold air moves downwards, while warm air moves upwards. So, when cold air enters at the window, it searches down into the radiator and is heated, after which the now warm air searches up and spreads in the room. This can however also be one of the culprits in the forming of condensations as the circulating of warm air that comes in direct contact with a cold surface will cause condensation. The problem only gets bigger if the room is un-insulated and have poorly glazed windows.

If you should counteract this, you will need a heat source that doesn’t move the air at all - thus you will need a radiant heat source. In short, radiant heat heats surfaces, objects and people in the room. A radiant heat source could be radiant heat panels or underfloor heating. A radiant heat sources will continue to radiate warmth to colder surfaces or objects in the room and the air will then get warm that way. As the air is not artificially circulated and thereby hitting cold surfaces - there will most like be not condensation.

This gives us a clue on how to avoid condensation - eliminate the cold surfaces and don’t move the air. This is just another reason why proper wall insulation, double-glazing windows etc. for optimum energy efficiency should be prioritized to minimize the cold surfaces the air and heat will encounter. As elimination of cold surfaces and no air movement is almost impossible in real life, a combination of convection heat and radiant heat would be preferable. Most Hudevad radiators produces a mix of radiant and convection heat with a typical distribution of 70/30, i.e., 70% convection heat and 30% radiant heat.


Do you need help?
If you need more information on the subject, you are always welcome to contact a specialist at Hudevad. We are happy to guide you.




Too low humidity
When the air in a room feels dry, it is often due to low humidity. Rooms that are not sufficiently heated often have low humidity, which dries out the skin and increases the amount of dust in the room. Negative consequences of this include an increased risk of allergies and asthma. In addition, dry air can irritate the lungs and increase the risk of viral infection.

Too high humidity
Although the effects of too low humidity are negative, the consequences of too high humidity are even worse. It increases the humidity of interiors and surfaces such as plaster walls and window sills, which are perfect conditions for the growth of mold and bacteria. And it can cause several diseases and general health problems such as allergies, fatigue and headaches.


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