From what condensation on the windows. Condensation on plastic windows. Reasons for education, ways to solve the problem. Additional factors affecting window fogging

Master of Architecture, graduated from the Samara State University of Architecture and Civil Engineering. 11 years of experience in design and construction.

Plastic windows perfectly fulfill their function: they perfectly retain heat, isolate street noise and keep the temperature in the room. But a frequent occurrence is the appearance of condensation on glass in the cold season. Why do plastic windows sweat in winter and how to fix this problem?

Causes and consequences of fogging windows

The reason for the fogging of windows lies in the physical properties of the water. Being in a gaseous state, it is invisible, but when the temperature drops, the so-called dew point is reached, that is, water vapor passes into a liquid. It is in this case that condensation forms, which settles on the plastic windows.

If the windows began to fog up from the inside, there can be only one reason - a defective glass unit... This element of the entire system must be sealed, and in case of violation of such a condition, water vapor enters the interior, where it settles on the inner glass when cooled. This problem is eliminated by replacing the glass unit, the frame can be left.

Most often, however, condensation forms on the outer surface of the window. Why do plastic windows sweat in winter and how to eliminate this factor? There may be several answers to this question:

Subsequently, fogging leads not only to a violation of the view through the glass. Often this process provokes the emergence of worse phenomena:

• Freezing of windows and the formation of ice on them.
• Excessive humidity is the cause of mold, rot and mildew.
• Water and low temperatures gradually destroy foam in the gap and break the tightness of the entire system and the house.

What to do with this negative impact and how to eliminate the causes of fogging windows?

Troubleshooting

If your windows are leaking, you need to establish the cause of the phenomenon. It happens that the situation arises as a result of placing a large number of indoor plants on the windowsill, which evaporate a large amount of moisture.

Adjusting windows

You can verify what is the cause by doing a simple inspection of the entire window. The first thing to do is to check the correct adjustment of the sashes and the degree of their locking.... This is done as follows:

• You can feel a strong draft by running your hand along the window.
• Set fire to a match or candle, if the light fluctuates, then the tightness is broken.
• Paper is laid in the sash and locked. You can pull out the sheet without any effort.

If deficiencies are found, proceed with the adjustment. The sash is set vertically and horizontally with screws located on the lower hinge.

The degree of pressing is regulated by eccentrics at the ends of the window, as well as by tightening the pressure plates.

Don't forget about seasonal window settings. To do this, the regulators are turned with a marker inward for the summer, and towards the street in winter.

Window sills

Often windows cry due to improper air circulation during the cold season. The reason lies in the wide window sills, which block the access of warm air masses to the surface of the glass unit.

In this case, in order to normalize circulation in the window sill, you need to drill several holes, which will provide normal access of heat to the glass.

You also need to pay attention to the grilles that cover the heating radiators, perhaps they also impede air exchange.

Slope finishing

If the window was installed with violations of technology (leaking gaps, the frame moved), then contact the installation company. Installers are obliged to fix this problem free of charge.

An independent attempt to seal the gaps may not correct the situation, since the glass unit was originally installed incorrectly.

The situation is different with slopes. If the finish has not been done, it must be carried out immediately, otherwise this will lead to the complete destruction of the polyurethane foam in the gaps. To prevent the windows from crying, it is best to additionally insulate them using heat-insulating material (mineral wool, foam or foam).

Fittings

Quite often, windows cry because of poor-quality or worn-out fittings. All mechanisms must function normally and smoothly lock the sash in compliance with normal pressure.

Carefully inspect the seal. It must be elastic, without tears and cracks. If there is damage, and the elasticity is lost, they begin to replace it.

Ventilation

Ventilation of the room must be approached very carefully. This is especially true for rooms with a high level of humidity (kitchens, bathrooms), where glasses sweat most often in winter.

After all, plastic windows completely seal the room and impede air access from the street. The problem of air exchange can be solved in the following ways.

Check existing ventilation for blockages. This can be done by setting fire to the candle near the channel exits. If the light does not deflect, then the hood does not work. The grates are removed and cleaned until normal operation is restored.

However, in addition to the exhaust system, supply ventilation must also be present. This issue is solved by installing ventilation valves on the windows.

Today there are modern supply systems installed in the window handle, they do not spoil the appearance and provide a sufficient volume of fresh air.

By ensuring a normal level of ventilation, the problem of high humidity is also eliminated..

Thermal insulation

Single-chamber double-glazed windows are used in most non-residential premises, where thermal insulation is not so important. If such a double-glazed window is mounted in the living room, then it will not provide adequate heat conservation.

The problem can be eliminated by insulating the slopes and applying an energy-saving film to the glass. But these measures will not ensure full heat retention.

Optimizing humidity levels

As mentioned above, this phenomenon can be eliminated by ensuring normal ventilation of the rooms. However, if this does not help, then you can mount moisture-absorbing devices under the windowsill. Such cartridges are inexpensive in terms of cost, and their efficiency is quite high..

Recent renovations can contribute to an increase in humidity in the room. A large area of ​​plastered surfaces evaporates a huge amount of moisture, which ventilation cannot cope with. This is a temporary phenomenon and as the walls dry out, the moisture level will return to normal.

As a rule, these are the main reasons that windows cry in winter. When they are eliminated, the situation will normalize and there will be no fogging problems.

In cold climates, the thermal insulation and ventilation of the premises must be calculated very accurately, otherwise it may appear condensation on plastic windows, which is quite difficult to fight.

Plastic window construction

Today, plastic windows have gained immense popularity compared to aluminum and wood frames. The main reasons are the soundproofing properties of glass units, as well as their low thermal conductivity and absolute tightness, which cuts off the access of dust to the apartment. Let's take a look at a typical PVC frame design. Thermal insulation is achieved through several chambers, into which the inner part of the frame is divided, their number may vary. The 4 mm thick glass also prevents heat from escaping from the apartment.

Sealing of plastic windows is provided by rubber seals, which are clamped between glazing beads - special plastic sides that cover the glass along the perimeter... The same seals are installed around the swing leaf and in the place of its pressing along the perimeter of the frame. Thus, the tightness of the structure does not allow warm air to leave the apartment and prevents moisture from escaping. In some models of double-glazed windows, a supply ventilation valve is provided, which reduces the excessive humidity of the microclimate in the premises.

Why does condensation occur on plastic windows?

There are no perfect systems, and a metal core is necessarily inserted in the central chamber of the plastic frame, which is necessary for the structure to hold its shape. This insert can serve as a bridge for low temperatures if you choose insulating glass units that are not suitable for the climate in the region. Now imagine what the cold can do when it gets into a warm room. Both in a country house and in an apartment, the air contains a considerable amount of moisture.

In front of you, in an expanded form, the process of formation of the so-called "dew point" is taking place. There is always a critical temperature, a kind of bar, above which the air is oversaturated with moisture, and below which it is freed from it. With the right approach to building a house, it is possible to create such conditions that the "dew point" appears outside the living space or forms in the thickness of the wall. However, on the border between the warmth of the room and the winter cold outside the window, changes can always occur that will shift the "dew point" inside the apartment or house.

However, when designing an apartment or a country house, the above conditions for the appearance of condensation are taken into account and are not allowed. In particular, central heating radiators are located under the windows precisely for the purpose of forming a heat curtain against the cold. To ensure better heating of the glasses, the frames are installed closer to the inner edge of the window opening, and the width of the window sills is carefully selected so that they do not interfere with the warm air rising up. But it is worth making ill-considered changes, and the balance in the heat curtain will be upset.

Errors during installation of double-glazed windows and the appearance of condensation

Seeing drops on the inner surface of the glass, do not be indignant and look for defects in the glass unit. It is the appearance of condensation that indicates that the window structure is absolutely airtight, that is, it does not allow excess moisture to leave your apartment. Therefore, you need to either look for a cold bridge, or find out why condensation arose on the plastic windows, what is the reason that the border of the temperature difference was inside the room. If the plastic frames were installed by invited specialists, keep in mind the fact that they are not familiar with the peculiarities of the thermal regime of your home.

Very often, seemingly insignificant little things can cause the glasses to fog up. Suppose the owners are passionate lovers of indoor flowers. Plants love light, and therefore it is advisable to put pots with them near the window, which means wide ones are needed. But if these are not provided for in the project of the house, the extra 5-10 centimeters of the window sill protruding into the room can become a serious obstacle to the warm air rising from the radiator. This means that glass heating will deteriorate significantly. So is it any wonder that condensation appears?

Suppose the owners are aware that the window sill protruding into the room will affect the thermal curtain. However, you need to put flowers on the window, and when you install the frame, it moves closer to the outer edge of the opening. In fact, nothing interferes with the warm air rising up, however, wide ones stand on its way to the bottom of the glass unit. And the uneven distribution of heating just leads to the emergence of a temperature drop point. And, by the way, let's remember those same indoor plants, because they are just the source of excess moisture, the amount of which in the air should be regulated by high-quality heating and regular ventilation.

How to get rid of condensation on glass?

It has already been mentioned more than once that the absolute sealing of plastic windows prevents excess moisture from being removed from the air in the room. The emphasis on this fact is not in vain, since the main means of combating condensation is high-quality ventilation. At the same time, it is not at all necessary to pierce the air ducts in the wall, it is enough to purchase a double-glazed unit with a special ventilation valve.

The system of closing doors with manual or automatic adjustment will allow you to ventilate the room at any time and get rid of excess moisture in it. Automatic valves equipped with a special air humidity sensor are especially convenient. Doctors know that it is easier to prevent than to cure, and they are absolutely right, therefore, it is better to exclude the possibility of condensation in advance by installing a double-glazed window.

Alternatively, in order to save money, a single-chamber plastic window with additional glass can be installed. It is better to give preference to frames with a maximum number of chambers, which will interfere with the reinforcing liner itself as a cold bridge. The width of such windows exceeds 70 millimeters, but it is recommended to install them at least in the middle of the opening or closer to the room. It should be remembered that in cold climates, three-chamber double-glazed windows are installed, as a rule, in unheated, non-residential premises.

And finally, a few more words about room ventilation. It is very fashionable to use fittings for micro-ventilation in double-glazed windows, for which such a mechanism as "scissors" is used. By turning the lock handle 45 degrees, you slightly open the window frame with this simple action. However, it should be borne in mind that a gap of several centimeters wide provides an insufficient outflow of moisture, which is why the window has to be kept ajar for a long time. All this time, cold drafts are walking around the apartment, the slopes are cooling down. It is much more efficient to simply open the sash fully for 5 minutes.

Condensation is the most common problem faced by PVC window manufacturers and their customers. It should be noted that condensation is not only an unpleasant aesthetic defect, but it can cause moisture in building structures, and as a consequence of the appearance of mold!

According to the norms, the temperature of the indoor air in the premises must not be lower than + 18 ° С; in a number of regions, the Territorial Building Standards (TSN) have been adopted, which prescribed the temperature of residential premises not lower than + 20 ° С. If the temperature is below the standard, then it is necessary to check the heating system, because this can cause condensation to fall out.

Condensation occurs primarily at the bottom of the glass unit. Due to convection, cold air accumulates in the lower part between the glass panes. Therefore, the bottom and bottom corners of the glass unit are the coldest parts of modern window construction. Since the question of the marginal zone often arises, the State Construction Committee of the Russian Federation gave an explanation on this problem in letter No. 9-28 / 200 of 03/21/2002:

"1. The fallout of condensate in the edge zones on the inner surface of glass units during the winter period of operation, as a rule, is associated with the presence of an aluminum spacer frame in their structure and the conditions of convection of gas-air filling.
International norms (ISO, EN standards) allow temporary formation of condensation on the internal glass of an insulating glass unit.
But the standards for window blocks do not normalize the formation of condensation, since this phenomenon depends on a set of third-party factors: air humidity in the room, design features of the junction points of window blocks, insufficient air convection along the inner glass (due to a wide window sill board, improper installation of heating devices ) and etc.

At the same time, it does not allow condensation to fall out inside the glass unit, which should be considered a significant defect leading to a decrease in the standardized performance characteristics " .

Concerning high air humidity, then this phenomenon is characterized by the following main reasons:

• Insufficient air exchange due to too tight windows and, as a result, poor operation of the exhaust ventilation.
• Increased humidity in building structures due to recently completed construction or renovation work. Building structures retain moisture for one to two years after the end of the work!
• Features of the everyday behavior of residents. For example, a greenhouse on the windowsill or drying baby diapers in the kitchen ...

New norms SNiP 23-02-03 "THERMAL PROTECTION OF BUILDINGS" determined the calculated parameters of the relative humidity of the premises to determine the dew point and the temperature requirements on the inner surface of the windows:

5.9 ... The relative humidity of the internal air to determine the dew point temperature in places of heat-conducting inclusions of enclosing structures, in corners and window slopes, as well as skylights, should be taken:
- for premises of residential buildings, hospitals, dispensaries, outpatient clinics, maternity hospitals, boarding houses for the elderly and disabled, general education children's schools, kindergartens, nurseries, nursery schools (factories) and orphanages - 55%, for kitchen premises - 60%, for bathrooms - 65%, for warm basements and underground floors with communications - 75%;
- for warm attics of residential buildings - 55%;
- for premises of public buildings (except for the above) - 50%.
5.10 The temperature of the inner surface of the structural elements of the glazing of windows of buildings (except for industrial buildings) should not be lower than plus 3 ° C, and of opaque elements of windows - not lower than the dew point temperature at the design temperature of the outside air in the cold season, for industrial buildings - not lower than zero ° C.

What other mistakes can lead to condensation? It is necessary to check the premises for cold surface!

Causes of Cold Surfaces may be associated with resistance to heat transfer and with blowing of structures... They can be as follows:

Errors in the manufacture of windows:

1. Installed "cold" double-glazed window with low resistance to heat transfer, which does not meet the standards.
2. Violation of the clearance tolerances, the use of a non-standard seal or improper installation of the hinges are the reasons leading to the blowing of the window.
3. In the non-opening flaps, drainage holes of 5x20 mm are made instead of holes for draining the cavity between the edges of the glass units and the folds of the profiles with a size of 5x10 or no more than 8 mm in diameter. That is, we are talking about a violation of the provisions of clauses 5.9.5 and 5.9.6 on the system of ventilation and drainage openings. We sent a letter on this topic, and we want to remind you again: according to GOST, there are drainage holes, and there are ventilation holes. These are different types of holes! In the letter of the Gosstroy of Russia No. 475 dated 09/10/02, in clause 2, it is stated that "when the doors do not open, the dimensions and location of the holes in the lower profile of the box should not contribute to overcooling the lower edge of the glass unit." Confusion in this matter is often associated with terminology: in GOSTs there is no concept of "fixed" glazing or a window, but there is the concept of "non-opening sash"! That is, in the version that in everyday speech we call a "blind window or glazing" in the terminology of the norms - "not opening sash"!

Installation errors

1. Errors in the execution of the assembly seam: incomplete foaming, which reduces the resistance to heat transfer; poor protection against climatic influences outside, which leads to blowing or wetting of the foam; absence or poor vapor barrier, which also leads to wetting of the insulation, but already with steam from the side of the room.
2. "Cold bridge", when, due to improper design of the abutment unit, the window falls into the cold, sometimes even negative temperature zone of the wall. This reason is often encountered when profuse condensation occurs.
3. Blowing through a wall structure, for example, a brick wall, through empty seams - "wasteland". Such a phenomenon can be encountered on houses of the socialist period - the builders did not fill the vertical seams well. But this has also become a problem in new construction with multi-layer walls, when mineral wool is covered from the outside with bricks or other cladding. In this case, the insulation must be ventilated, and when the windows are placed in the plane of the insulation, they may be exposed to cold air from the side of the junction. In this case, it is better to separate the wall from the junction during installation with a layer of expanded polyethylene with a thickness of 6-10 mm.
4. The wide window sill prevents warm air convection from the radiator in the window opening.

Therefore, we can give the following tips to eliminate the possibility of condensation:

If, nevertheless, condensation was the result of increased air humidity, then this reason must be eliminated due to the increased likelihood of mold in the room. To lower the air humidity in rooms and transfer the dew point to lower temperatures, we recommend installing a Regel-Air climatic valve or ventilating the room for 10 minutes twice a day.

Heat loss with such ventilation is insignificant even in winter and is no more than 3 degrees.

The intensity of ventilation of the room must be increased when carrying out repair work.

The window sill should not be very wide and impede the passage of warm air.

To allow warm air to pass to the window, place the curtains at some distance from the window sill.

Decorative screens for heating radiators should not impede the passage of heat fluxes from radiators.

The exhaust ventilation system in your home or apartment should be checked periodically.

One of the most effective ways to combat condensation will be the installation of a window with a five-chamber system "Favorite", developed by "THYSSEN POLYMER GmbH" (Germany) especially for Russia.

The temperature on the inner surface of the profiles directly depends on the heat transfer resistance of the profile system. For example, we can consider two cases - at an external temperature of -26 ° C and at -31 ° C (at an internal temperature of +20 ° C and a relative humidity of 55%). In this case, the dew point will be +10.7 ° C. The temperatures on the surfaces of a typical binding (three chambers and a width of about 60 mm) and a five-chamber binding with a heat transfer resistance of 0.78 m2? C / W will be as follows:

The material was prepared by Sergey Korotkikh,
LLC "Fenster".

Reading time ≈ 3 minutes

When the renovation in the apartment is completed, it seems that nothing can interfere with your peace of mind. But there is one extremely unpleasant moment: during periods of cold snap, condensation appears on the plastic windows. It seems to many people that this is a completely normal and, in principle, expected phenomenon, but in reality everything is not so.

Why does condensation form on plastic windows?

The reasons for the appearance of condensation on plastic windows are different, so you need to keep track of when and how it appears.

There are three types of reasons, conditionally they can be divided as follows:

1. Manufacturer and installer errors.
2. Placement of radiators and a wide window sill.
3. Total air humidity.

Most often, ordinary consumers are faced with a low-quality manufacturer who saves on materials. In such cases, the result of the fraud makes itself felt in the very first winter. Due to the fact that the production process was somewhat disrupted, a so-called decrease in heat transfer appears, which, as a result, has an unpleasant result in the form of condensation on plastic windows.

There is also a second reason - an error in the installation of glass blocks. In this case, it was the workers who made the mistake. Incorrect measurements and application of polyurethane foam, installation of a wide window sill (at the request of the customer himself) - all this can also lead to condensation on the plastic windows from the side of the room.

There is also a third reason - high humidity in the living space.

How to get rid of condensation on double-glazed windows?

1. Many people know that if the cause is not eliminated, then it is possible to acquire a dangerous fungus and mold. To get around these difficulties, in this case, you need to use a fan that will be able to balance the temperature. If you set a moderate fan speed, then in a few hours the condensation on the PVC windows will disappear. Thus, you normalize the room temperature.

2. If this method seems ineffective to you, then you can apply another method. Its essence is to improve ventilation. It is usually sufficient to check the entire ventilation system, which often clogs up.

3. Airing - the simplest and easiest way, which is popularly considered the best solution to the problem. So you can eliminate condensation on the plastic windows from the side of the room quickly enough, but the procedure should be repeated daily. So you will reach the temperature at which condensation will not appear.

Remember, so that this problem does not affect you, you should initially order plastic windows from trusted manufacturers, and the installation of double-glazed windows should be trusted only by professional craftsmen.

With the advent of cold weather, people often contact us with the following problem: condensation accumulates in plastic windows. Maybe at first glance there is nothing terrible here, but in fact this is a rather serious problem that is not so easy to solve on your own. Most often, so much seemingly innocent moisture in the windows indicates a depressurization of the glass unit - with all the ensuing consequences.

In this article, we would like to consider the main causes of condensation in plastic windows, and also talk about what to do about it.

Condensation on plastic windows: introduction

So, condensation has appeared on your plastic windows. It flows down to the windowsill, forms puddles, sometimes ice appears directly inside the room. It looks, to put it mildly, not very aesthetically pleasing, but even more unpleasant from a practical point of view. Due to the excess amount of moisture, mold begins to form on the window frame, and the glass unit itself no longer protects the room from the influence of the external environment as it should.

You understand that you need to do something about this, but you have no idea where to start. In order not to waste time, we suggest contacting our consultant. If you go this way, then the problem can be eliminated as soon as possible.

Advice! If you notice that it began to see through from the window or some other misfortune has occurred, then it is better to immediately eliminate the problem. As long as it is warm outside, most likely it will not bother you. But when the cold weather comes, you will understand how serious everything was.

So why does condensation form in plastic windows? The main reason is the so-called dew point. When cold air comes into contact with warm air, steam is formed. This very steam is trying to escape by any means. However, a plastic window is in his way. When warm steam comes into contact with a cold window, it turns into water - this is condensation.

The second most common cause of condensation is flowing interpanel seams. When installing plastic windows, all seams and joints must be closed. And not only with polyurethane foam. Everything should be additionally waterproofed with special means, and finally, treated with a sealant that will not let moisture through. Then the design will serve faithfully for a long time. If this is not done, then the insulation, which is in the panel, will begin to gain moisture, and then give it to the room. This is where condensation will appear on the windows. It is difficult to cope with such a misfortune on your own, since it is difficult to detect current seams without special equipment. The professionals of "Heat of Home" will always come to the rescue.

Condensation on windows: reasons for formation and a guide to action

So, why does condensation form on pvc windows? Reasons and methods of struggle:

• High humidity... Of course, in the first place is the high humidity in the room. If the humidity in the room is more than 60%, then the formation of condensation on the windows is inevitable.

Solution... In this case, you can get rid of excess moisture in the room using conventional ventilation. You need to do it regularly. If this is the only problem, then when the humidity in the room returns to normal, condensation will stop forming.

• Wide window sill... Oddly enough, a wide window sill can also cause the aforementioned problem. If the window sill overlaps the radiator by more than 1/3 of its width, then it can thereby impede the flow of warm air. As a result, the window sill is cooled, the glass is cooled, the frame is cooled - the result: condensation inside the PVC window.

Solution... What to do? Select a window sill that will not block the radiator.

• Glass unit construction is another reason for window freezing. It only seems to you that the plastic windows are of the same type. In fact, they are very different from each other. Sometimes an incorrectly selected glass unit can be the very reason for the formation of condensation on it.

Solution... ... How can you avoid this situation? You need to order plastic windows only from a trusted company, whose specialists will make the necessary calculations for you, take into account all the requirements and perform the work efficiently.

• Low temperature in the room, as well as high, can cause condensation. This happens when the yard is already cool, and the room has not yet begun to heat.

Solution... To remove the "dew point" can be a banal increase in temperature in the room.

• Poor installation... Perhaps the most common reason for condensation in plastic windows is poor-quality installation. Today, many inexperienced companies have begun to work in this area, which are simply unable to take responsibility for their work. As a result, incorrect attitudes quickly manifest themselves. The owner is faced with problems that sometimes end.

Solution... In order to understand how to solve this problem, you need to know exactly what the mistake was made when installing the plastic window. If you cannot cope with the situation on your own, then you should contact our specialists for help. They will quickly identify all the problems and offer you several options for solving them.

• ... Sometimes condensation inside plastic windows appears due to the lack of regular window maintenance.

Solution... Adjust the window, lubricate all hardware mechanisms, possibly replace the seal. In fact, the problem could be anything. To say for sure, an individual inspection of the metal-plastic structure is required.

In fact, the problem could be anything. To say for sure, an individual inspection of the metal-plastic structure is required.

Thanks to the table below, you can determine the dew point temperature yourself. To make calculations, you will need to find out with the help of a hygrometer and a thermometer the relative humidity in the room and the air temperature.

Why condensation forms in a plastic window: video

Especially for you, we have prepared a video in which we talk in detail about what can be one of the reasons for the fogging of a plastic window from the inside. The specialists of the Teplo Doma company promptly went to the call of one of the clients and decided to capture their work on camera.

So, in our article we figured out why condensation appeared in plastic windows. In the overwhelming majority of cases, this is due to the depressurization of the double-glazed unit, which means - with the need for its further replacement. To clarify the "diagnosis" and solve the problem, we recommend calling a specialist: an independent fight against condensation often does not lead to the desired results. You will surely feel the consequences of this approach in the coming winter.

Where to order repairs?

We are a company for which window renovation is not just a profession, it is a life choice. Without exaggeration, we know everything about plastic windows. And if you do not understand how to get rid of condensation on the windows, then the Teplo Doma specialists will be happy to help you with this. Do not postpone window renovation until later - consult with our consultants today!