Wood Windows versus the humidity and ventilation


The function of the Windows:

In the overall design of the building are a number of features, whether it be window provides illumination of the Interior of the Sun's radiation or contact with the outside environment. It is also becoming a common means for the supply of fresh air into the rooms. Otherwise the way, which we acquit used and wet air from the interior. In the construction of buildings represents a window compared to the walls by the weaker (in terms of heat-technical properties), it is therefore necessary that the construction and associated details (lining, parapets) paying due attention. The fact that these structures are thermal-technical parameters for the worse, there is a distortion of the temperature (more quenched area), as higher heat losses and a larger cooling surfaces. After some circumstamces, it leads to the condensation (retting) the water vapour on the all windows or on the related structures (lining, parapets). Pic. 1, 2


funkcia okien    funkcia okien

Pic. 1,2 retting of the board of the glass, wet lining

Moisture in residential areas
From this perspective, it is necessary to pay due attention to the right humidity in the living space. Water, the absolute necessity for human life, it occurs in various forms. The most dangerous for the Windows is in the form of water vapour, since we don't see it immediately, but only after condensation. Just water vapor and condensate can cause considerable damage. The moisture content, which is located in the residential premises, or from the use of technology can be. Technology is that there is a still from the time of the House construction of wet processes. It's water from the concrete, plasters, spawn, etc. This is most common during the first year of construction released, but the quantity is enormous, because it is in the construction phase to ensure intense ventilation. Moisture from the use of the moisture in the accommodation consists of a continuously, while the sources of moisture is cooking, washing, drying, washing, showering, an aquarium, a person during sleep, houseplants. This moisture must be paid to proper and constant attention as well. The most common consequence of excessive moisture is the formation of mold.

What happens after you replace Windows?
The greatest attention must be paid to the seeding of new Windows in new buildings or replacing old Windows for new Windows during the first year. In particular, the exchange of old Windows with new ones, completely changing the climate of the entire living space. Temperature and humidity parameters have changed the living environment. Therefore, you need to get used to the fact, and what was the old saying Windows (ventilation of the chink) now becomes the responsibility of the user. If replacing the old Windows also connected with reconstruction of living space, respectively, for the construction of the mount another major source of moisture-humidity technology building. When the exchange is necessary to fix the "lining" window (plaster of scuntion), which is a wet process, which brings with it the humidity.  This technology we get rid of moisture during the first year. Therefore, after the replacement of Windows, pay special attention to ventilation. The formation of condensate on the sklách or in the vicinity of the window is a symptom of errors (most commonly elevated Interior humidity) and the need to immediately determine the cause of the formation of condensate and then delete.


Tvorba plesní

Pic. 3 The creation of the mold with the abnormal moisture in the interior

It is absolutely one of the base used in the manufacture of window balance goes, whether it be wood, plastic or aluminum. From these materials, wood is the only active material, which in practice means that it is to some extent able to eliminate moisture in the interior. The wood is able to accept and transmit humidity into the surrounding environment, it is a material that is able to breathe. After overcoming a certain boundaries, or wood with an excess of humidity is able to tackle. That just mentioned should be as small as possible the effects of humidity on wooden Windows, considerable attention in the development of varnish on the surface treatment of the window is dedicated to this issue.

The role of the surface window treatments
The Firm ADLER as a leader of innovation in the field of surface treatment with the introduction of modern technology, many of these negative effects of Windows to completely remove or significantly repressed. The key is for customers for wooden Windows just finishing plays a significant role. With the system Adler generation 3 or HighRes benefits not only the manufacturer of Windows, but also significantly (processor varnish) the end user customer. From the manufacturer or from other sources, the user becomes aware that the Windows are finished s.c. thick film of scumble. The term is often mentioned, but rarely or not at all unexplained. What does thick film of scumble mean? There are two concepts that don't say anything laikovi, although they often met. The scumble is a pigmental varnish with the pigments inside. It can be  solvent ( „ synthetizm“) or diluent by water. In this time it uses diluent by water. The second meaning is thick film system. The name is derived from the film thickness in dry condition, so from the thickness of which remains on the surface after the dry. For the thick film system the thickness is designed for 80 μm. In practice for laquering, this means the thickness of the varnish is in a wet condition 250-300 μm1. The thickness of the dry film is set at 80 mm, but in practice you will encounter with the painting of the outside of the window blew in, twice (one 500-600 µm wet spraying, or two sprays after 250-300 µm), which represents the thickness of the film, in the dry state, of 150-200 µm! Lay people often believe that the higher the thickness, the better the resistance to moisture and lasures blocker lifetime total. The great thickness of the paint film is more impressive to the eye and feel when touched, for window, however, is a problem. Such a layer of varnish is a huge barrier to moisture on the outside of the window switching. Apply here the principle that less is often more. It is necessary to remember that today's production of wooden Windows is, as to the accuracy, machining with tolerances in tenths of a millimetre, works here. And these exact dimensions from the production protects thick film of scumble after the attack of moisture. From the point of view of moisture are important two facilities of the varnish, and it is protection against water pic. 4 and permeability of the water vapour pic.5

obr. 4.      obr. 5.

Pic. 4.                                                                               Pic. 5.

Water protection is deemed to be from the outside, where the window is exposed to the weather. In the rainy season, which is exposed to running water in the window must finish to resist. For the standard scumble and prolonged exposure to water on the surfaces are lighter, what signalizes the saturation of scumble with water. Of course, this is a weak point, that is, at that moment the lack of surface treatment. The film of scumble generation 3 formed s.c. netting, in order to reach an integrated surface resistant to flowing water. On the pic. 6. to see different between a scumble and the scumble ADLER Generation 3.


Normal scumble                   Scumble Adler Generation 3


From the perspective of the history of the systems have gone from dissolvent to diluent of the water, just from the perspective of the benefits the diluent of the water is better system (permeability of the water vapour).

Is ventilation necessery?
Of course, the best and most effective is to prevent problems associated with moisture. The cheapest and easiest way is ventilation. As is generally known, but greatest possible energy savings are possible right. However, it is important that the ventilation was effective and sufficient. On it, so that we can live in a healthy environment, we need plenty of fresh air. The amount of fresh air is provided for the present notice sets out the minimum flow minimum hygiene to 15 m3/1 os.
This information, however, is in sharp contrast with the expected energy savings from ventilation.
The old structure would cause excessive air exchange window, which was noticeable in the wind, draughts through for example snuffle from the rifts. Excessive loss led to the high energy costs for heating. For current weather conditions (no wind) is the minimum volume of air in the room netesnosťami swapped 1 x per hour, when the wind was the replacement of the air even more pronounced (namely, plenty of fresh air, but the huge heat losses).
When the current window is the window structure for normal weather happen almost hermetically sealed, thus causing no or inadequate air exchange.
In the ordinary course of life in the household activities produce moisture. As already mentioned, the source of the moisture in your home cooking, showering, bathing, washing, drying clothes, watering plants, the Aquarium and, of course, sleep. For example, the average person in one night sweats 0.5-1 litre of water! In addition to the moisture content of a person breathing produces CO2 (carbon dioxide), which causes fatigue, irritability, excessive quantities of fatigue, insomnia, etc.
For these reasons, you need to pay enough attention to ventilation. The amount of water in the air is called. relative humidity φ (PHI), with the label. Moving in the range of 0-100%. The ideal value is 50%. If the value of φ 30-40%, the air is dry (irritation of the mucous membranes, difficulty in breathing), if the value of φ 60-100% of the air is very humid (mold making, furniture, equipment, feeling cold, damp). In the long term must not be greater than 60% φ.
Humidity and ventilation has a direct link with the heating. At least the heat we consume in warm dry air. If you are located in a heated space, we need to be heated and moist air the water contained in the air. The physics is clear that we need a huge amount of heat to heat water. From the above, that is non-economic unchanged heated moist air.
The first symptom of excessive moisture in the interior is the condensing water vapor (retting) from the winter heating period, especially in the interior.
When using insulating double windowpane with U-value of 1.1-1.0 W/m2.This phenomenon would not be to. With the retteing of the interior side of the glass, it is possible to meet at the bottom edge of the glass due to the distance between the two panes of glass frame, that is. This frame is made from different materials. The most commonly used in the manufacture of frames, aluminum, stainless steel or plastic. Depending on the type of material is also the possible presence of retting glass on the edge of the glass pane  (especially when using an aluminium frame distance). The misting can be only 1-2 cm from the edge of the frame in the form of a fine vapour.  A greater range of retting Interior humidity is high, starting  Windows to the condensate to flow to and from the window sill molding, glazing. Long-term exposure to moisture than Windows, as well as the overall harms the internal equipment (furniture, textiles).
With increased humidity, it is possible to meet most in the kitchen, the bathroom and the bedroom.

Symptoms of excessive indoor humidity with respect to Windows:

  • condensation (retting) of glass from the interior side
  • excessive moisture in the Interior allows the spread of mildew, damp internal equipment of the apartment or house furniture
  • change the dimensions of the window (bulking agent-wood), which leads to heavy or no opening Windows
  • surface corrosion on the forging


Tips for ventilation
Don´t warm up the air that contains high humidity (over 60%). Rather, because of the cold and moist air from the exterior ventilate when heated to 20 ° C becomes dry, which consumes several times less heat than to keep moist air at a temperature of 20 ° (C) shall be brought.
Ventilate at least morning and evening, a room with high humidity or high humidity (bathrooms, kitchens) permanent production of additional device controlled by moisture. ventilate. In these areas should be given special attention to ventilation!
Already a light wind (about 5 km/h) the exchange of air per hour shall be doubled. Speedy ventilation can be carried out by a transversal ventilation through several rooms (draughts).
The rooms with open fire must be ventilated, as well kitchen with the gas cooker, because
increased content of hazardous combustion gases-sulphur oxides (recommended ventilation fume hood), the air can go through the slit.
When non-compliance with these principles will be subjected to extreme stress due to moisture that your Windows may lead to permanent or temporary damage your Windows. Higher humidity is a problem in itself, and blamed it on the only problem is reckless. The fact is that prolonged moisture damage to wooden boxes and plastic will not, however, neglect of this problem will manifest itself elsewhere (in the built-in cabinets in corners of the mold of the rooms).
Any damage of the Windows by abnormal moisture can´t be the item of the reclamation.

How to ventilate properly and economically the most efficient?
Aim is to achieve the maximum quality of the air in the room in which the ventilation a minimum energy consumption. However, if the Windows pops up retting, it is too late to think about energy saving. If it is necessary to ventilate. The time required for a complete Exchange of air in the room when a ventilation (open window) is dependent on the outside temperature in the course of the year, moving from approximately 4 minutes in the winter after 30 minutes in the summer.

The most accurate dedicated time to airing out the room, especially in winter, is as follows:


  • close the valves of the heater! (in particular the thermostatic)
  • open the window in the room wide open. When you open a window to the outside pane of glass will ret
  • ventilate until the glass remains clear.
  • close the window and adjust the valves back into its original position.


Who wants to live in a healthy and clean living environment, and it does not matter what material they are made of moisture and ventilation Windows must be under permanent control.