Why do plastic windows sweat and how to deal with this problem?

Modern plastic windows, the first of which were installed in Russia more than forty years ago, are an excellent alternative to the wooden windows familiar from childhood. A dense frame with double or triple glazed windows does not allow cold and noise from the street to pass through, is easy to clean and open, and looks beautiful. However, many users note that plastic windows sweat from the inside. Moreover, moisture can appear on the glass at any time of the year, regardless of the temperature outside the window.

Reasons for fogging of plastic windows

A foggy window primarily indicates an unhealthy microclimate in a cottage or apartment. There are several reasons for this problem, and only in 10% of cases the problem is directly related to a design malfunction and improper installation of the package. Basically, such a nuisance occurs due to high humidity and insufficient ventilation of the room.

• Poor ventilation

If you observe at what point a plastic window sweats the most, you will notice that this happens during cooking, washing dishes, boiling a kettle or a pot of soup, when there are a lot of people in the room, that is, the air humidity rises sharply. Droplets of moisture settle on the coldest surface, which at any time of the year, with the exception of hot summer days, is a double-glazed window.

The main reason why windows fog up is due to insufficient ventilation of the room.There is an opinion that wooden frames, unlike PVC, breathe, so the glass does not sweat. Yes, indeed, air from the street passes through the cracks in wooden frames perfectly, providing the necessary ventilation. But this is a dubious advantage, since with wooden windows the apartment is noisy and cold. To prevent plastic windows from sweating, it is necessary to ensure good ventilation in the apartment.

• Defective product

Not every PVC window manufacturer supplies high quality products. A double-glazed window consists of several glasses connected to each other and is a sealed structure. The chambers between the glasses are filled with dry air or inert gas. At the bottom of the glass unit there is a material that absorbs liquid. If, as a result of non-compliance with the technological process, the integrity of at least one chamber is compromised, then water will accumulate inside the glass unit.

• Poor installation

It is best to entrust the installation of a plastic window to professionals who are familiar with all the nuances of performing this seemingly simple job. As a result of incorrect installation, the frame will become skewed and the window will not close completely. As a result, cold air from the street will flow freely into the room, and the windows will sweat a lot. In addition, gaps may remain where the frame touches the window opening, which will also lead to the formation of condensation.

Choice of modification

When choosing a double-glazed window for a private house or apartment, you should take into account all the features of the structure, namely:

• heating type;
• number of windows;
• room area;
• Window openings face north or south.

To prevent windows from sweating, you need to pay attention to each of these factors.The number of cameras greatly affects the quality of the microclimate in the apartment.

What to do if plastic windows sweat?

To create a favorable microclimate in your home and eliminate condensation on windows, it is necessary to regularly ventilate the room. You need to open the transoms while eating, before going to bed and when going for a walk. In addition, several measures should be taken to reduce air humidity and increase the temperature of the glass, which will also correct the situation.

Reduce indoor humidity

There are several ways to reduce the percentage of moisture in a room.

• Install a forced-air hood in the kitchen. If the hood is already installed, you need to check its serviceability. It is possible that it simply does not work or is not operating at full capacity. In a private house, a fireplace can serve as a hood; you just need to open the damper a little.
• It is necessary to ensure a flow of fresh air. To do this, an automatic or mechanical supply valve is installed on the top sash of the window.
• If there is a problem with window fogging, you should get rid of all additional sources of evaporation. This could be an aquarium and other open containers with water, numerous indoor flowers in pots, and all kinds of leaks.
• To improve air circulation in a house or apartment, when installing interior doors, leave a gap of at least 2 cm between the leaf and the floor.
• Ventilate rooms regularly.

The reason for the appearance of condensation on the glass may be poor central ventilation of the building. Checking the operation of the general ventilation system is very simple. You need to light a match or a piece of paper and bring it to the ventilation hole.If the flame deviates towards the shaft, then the hood is working normally. Otherwise, it can be argued that the ventilation is clogged and requires urgent cleaning.

Increase glass temperature

The colder the glass, the more the plastic windows fog up. By carrying out the measures described below, you can increase the temperature of the glass unit.

• The most radical and effective way to solve the problem of window fogging is to change the double-glazed window. Instead of a single-chamber package, you can install a two-chamber one. Or purchase a design with low-emissivity k- or i-glasses, which reduce heat loss 5 times more than conventional ones. The thermal efficiency of a window is higher if, instead of dry air, the space inside the chambers is filled with argon or krypton.
• The glass temperature is not the same at all points. The lowest indicator is near the seals, especially in the bottom corners. It is here that the largest amount of condensate collects, and in winter, when it’s cold, ice even forms. The situation can be corrected by replacing the iron frames with plastic or polymer ones. The temperature of the glass at the edges will increase by several degrees.
• It is necessary to adjust the fittings and, if necessary, replace the seals with frost-resistant ones. This will limit the flow of cold air and reduce the cooling of the glass.
• The high-quality finishing of the joints of the profile and the window opening also greatly affects the temperature of the glass in the package. The cracks should be carefully sealed using polyurethane foam or sealant, and the slopes should be insulated.
• When installing a window sill, you need to make sure that it does not cover the top of the radiator and does not interfere with the upward movement of warm air.In addition, thick curtains, decorative cornices and screens installed above heating appliances should not interfere with the flow of heat to the glass unit.

An important factor influencing the temperature of the glass surface is the air temperature inside the room. If the room is warm (+25°C) and dry, then the likelihood of condensation is minimal.

How does condensation on windows affect your health?

Foggy plastic windows look unsightly, do not transmit light well, and make it impossible to look out onto the street. But the main problem is that an unfavorable climate is created in the room, which negatively affects the health of the residents.

PVC windows are so sealed that they do not allow moisture to evaporate outside. In a humid environment, harmful microorganisms and fungi multiply well, which is often evidenced by black spots on slopes. Pathogenic microflora hovers in the air that apartment owners breathe and settles on surfaces, which leads to diseases of the respiratory system, allergies and other ailments.

Normal humidity for a living space is 40%, air temperature is +22°C. If these indicators are observed, the appearance of condensation is almost impossible.

Plastic windows are modern designs that allow you to improve living conditions in a multi-storey building or cottage. To prevent them from sweating, it is necessary to maintain a balance between temperature and humidity in the room, ventilate the rooms more often, and install only high-quality products.