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Window condensation

Attention: window condensation specifically during cold winter

People buy and assemble windows, but attributes such features to them, which windows can have, or may not. Why do windows steam or frost?

Siauliai university docent Mykolas Peliksa said: ‘‘Human and building encloses react more to relativist air humidity than to absolute one. During winter, in the air water can only be dissolved up to 2 grams and relative humidity can be as high as 100 percent, but when heated to 20 degrees such air becomes too dry for dwellings, because its relativist humidity won‘t exceed 10 (it is recommended to keep humidity no higher than 30-60 per cent at dwelling houses)“.

If 75 percent relative humidity and 20 degrees room air would be refrigerated to 10 degrees, it is theoretically equal to a relative humidity of 100 percent.

So it means that in between accommodation and air temperatures there is a close contact, which can be called like this: the more we warm and ventilate premises, the less we feel humidity in it and condensation on cold covers will be reduced.

According to M. Peliksa, modern Windows cover temperatures supposed to be higher than 14 degrees, meanwhile outside temperature is minus 10 degrees and no lower than 10 degrees, when outside is minus 30 degrees (in both cases air temperature is 20 degrees). ‘‘When in premises there is normal air humidity, window glass should not only frost but also steam‘‘, - asserts M. Peliksa. It should not be forget that the humidity is associated with the indoor temperature.

What should be done that windows won‘t steam?

Docent offer to avoid to high humidity release indoor: cooking, washing, bathing and so on. Of course, we will not live without eating and bathing, but after that premises must be ventilated.

Humidity emanates when human is breathing (about 40 grams per hour), and sweating. Even burning natural gases release water vapour to atmosphere (burning one cube meter of natural gases releases no more than 1.6 kilograms water steam).
‘Ventilation is required when there is too much pollution and humidity excess in premises. If it’s possible, the best way to do this is to make draught and leave the premises for couple minutes while the weather inside will be amended.

So Windows condensation will be prevented by two easy procedures: adequate space heating and ventilation regularly. Manufacturers advise to ventilate the premises every day for at least 15 minutes after opening the windows or vents.

But here is important to ‘‘take the things easy‘‘. According to docent M. Peliksa continuous or prolonged ventilation can fall on walls, ceiling and window surface temperatures below the dew point that is why temperature for the right conditions to form a kite surface moisture condensation.

Resume what was said:
- the premises must be sufficiently heated, because they depend on the air relative humidity and condensation (dew point) temperature;
- the premises must be ventilated regularly: every 15 minutes or after a few minutes on draught, however, do not overdo ventilation.

Another tip for impatient ones - adds M.Pelikša – you can express your claims to window manufacturers only after you are sure that you fulfilled two conditions written above.