If you install a plastic window, be prepared for the fact that with the onset of cold weather it will often fog up. flow plastic windows- it is with such a problem that the owners of PVC structures turn to the companies where they were purchased. As a rule, the dialogue boils down to indignation: “You sold a low-quality product, the previous (wooden) windows did not cause us so many problems, please, correct the situation.” A person may not even guess why plastic windows are flowing - he blames the company in which he made the purchase for everything. This is not entirely correct. There are many reasons why condensation accumulates on the product. Why windows cry - we will answer this question. In addition, from this article you will learn how to deal with this phenomenon on your own. You will be convinced that repairing plastic windows with your own hands is possible.
Why windows cry - causes of condensation
To begin with, it is necessary to destroy the long-established stereotype that wooden windows don't sweat and that's the only problem plastic products. Any modern design with a double-glazed window, regardless of the material from which it is made, lends itself to "sweating" under certain conditions. It should be noted that single windows are more susceptible to this than double ones. This is due to the fact that two-frame products have an increased thermal insulation coefficient. Since PVC products are mostly single-frame, condensation on a plastic window accumulates faster.
On the other hand, it may seem that the material plays a paramount role - wooden structures Even in Soviet times, they practically did not sweat, unlike modern plastic ones. However, not everything is so simple here either. If the old windows had a good seal in the porch, and even had no gaps between the frames and glass, they would sweat no worse than PVC products. Plastic structures are reliably sealed. Upon their installation, the warm air in the apartment does not escape to the street, as this would happen with old windows. As a result, the humidity in the room increases. Hence, condensation appears on the plastic window. Consider the reasons why windows cry more closely.
- First, we should still touch on the topic of quality plastic structures. Not every window can be made to last. So in winter time, first of all, those products that were made from a thin profile sweat. This is due to the fact that they cannot retain heat in sufficient quantities. As a result of this, a dew point is formed, and the air near the glasses condenses into a liquid, settling on them. In addition, the appearance of moisture can be affected by the quality of the fittings, as well as the lack of special openings for slotted ventilation. Taking into account all these factors, in order to avoid possible problems in the future, windows should be ordered from reputable and time-tested suppliers. If a poor-quality design has already been installed, you should contact service center for the help of experts.
- Secondly, plastic windows most often cry because of their tightness. This is observed if there is no normal ventilation system. In this case, the tightness coefficient should not be attributed to the design flaws, on the contrary, this is its main advantage. Plastic windows are crying to a greater extent due to a poor-quality ventilation system. In such conditions, moisture on the product will accumulate constantly.
- Thirdly, the width of the window sill may be the cause of condensation on the glass. No matter how strange it may sound, this design can contribute to the formation of moisture on the product. This is due to the fact that the protruding window sill plays the role of a kind protective screen, blocking warm air flow. As a result, the air stagnates due to violation of convection. As a result, the window fogs up quickly. To exclude such a possibility, the attention of the measurer should be focused on this when ordering the structure.
- Fourthly, plastic windows often cry from problems with heating the room. If the heating system is working correctly, this will to some extent be a guarantee that you will not have to deal with fogging of the windows. Optimal temperature regime indoors, it contributes to the formation of ascending currents that prevent the air from cooling to the dew point, which accumulates near the window.
- Finally, the most common cause of condensation on glass is high humidity in the room. The most obvious example is the kitchen. During cooking, steam is regularly generated here. As a result of this, windows often sweat. However, this is not the only place where condensation can be observed on the product due to high humidity. For example, such a picture can be seen in the bathrooms.
Of course, this phenomenon should be combated, since humidity also negatively affects other factors besides the formation of moisture on the glass. For example, a fungus forms in a room, which has a negative effect on building materials and even on human health. In addition, the fungus can cause even more active condensation on the plastic window.
The dew point is nothing more than the temperature to which air is cooled and then saturated with water vapor at a given humidity and constant pressure. As soon as the dew point is reached, water vapor condenses in the air itself or on objects in contact with it. At a relative humidity of less than 100%, the dew point will remain below the air temperature and the lower the relative humidity, the lower its temperature will be. At 100% humidity, the actual air temperature will coincide with the dew point.
The image below shows the surface temperature with maximum accuracy at atmospheric pressure, which is normal (762 mmHg). Condensation will form on such a surface at a known air temperature and its relative humidity:
Everything here is outrageously simple. If the window fogs up, just open it for 10-15 minutes to ventilate. When you close it, you will find that all the condensation has disappeared. The reason for this lies in the physics textbook for the eighth grade. At a given temperature, the air can contain a strictly defined amount of vapor. For example, in a steamed bath at t=+80°С, the content of steam exceeds its amount in dry air tenfold. When the window is opened, the humid air in the room is replaced by dry air from the street. As soon as the temperature drops to normal limits (~20°C), the relative humidity of the air decreases and the condensate disappears.
Optimal conditions for residential premises - relative humidity 40%-50% at a temperature of 19-24°C. If such a regime is maintained in the room, you will be able to avoid the appearance of condensate on the slopes, the frame, or the double-glazed window itself. Least of all, increased humidity in a room depends on human activity - the main factor affecting it is poor-quality air exchange. In other words, in a well-ventilated room, the likelihood that condensation may appear on the windows is rapidly reduced to zero.
conclusions
- First of all, it is necessary to ensure the sealing of the inner binding of the window wound so that as little air as possible from the room gets into the space between the panes. In this case, moisture cannot get on the outer glass.
- Since the workmanship of most of our windows is such that complete sealing of the binding is impossible, it is necessary to ensure ventilation of the space between panes. That is, there should be as few gaps as possible between the inner frame of the window and the binding, and between outer frame and bound gaps should remain.
- But, of course, they should not be very large. Indeed, in this case, the inner glass will be cooled and condensate will already accumulate on it. True, now it will not freeze and accumulate on the windowsill, but will begin to drain to the floor of the room, which is also unpleasant. Therefore, usually, if the gaps between the outer binding and the frame are small, they are not sealed at all, but if they are large, small areas at the top and bottom of the binding are left unsealed. Old traditional materials are also suitable for this work.
- The joint between the glass and the binding is smeared with window putty, and the gaps between the binding and the window are pierced with tow (or any other material) and pasted over from above. True, paper is not particularly convenient for this: it can be difficult to remove it in the spring.
Another method
- Prepared strips of white fabric (usually from old sheets) are moistened with milk, rubbed laundry soap and glued on.
- After drying, the mixture of milk and soap forms an airtight film, and in the spring the fabric can be easily removed after being wetted with water.
- It can be washed and reused.
- But now in the shops of the city there is wide selection more convenient imported window sealing materials.
- The joint between the glass and the frame is better treated not with window putty, but with rubber-like silicone sealant. After all, putty is a short-lived material, it quickly cracks, and then falls off.
- Silicone sealant, on the other hand, not only lasts almost forever, but also provides a much better seal. This is already evidenced by the fact that it is increasingly used for gluing frameless glass aquariums.
- To seal the gaps between the frames and the binding, it is better to use self-adhesive rubber compressor. It is available in various thicknesses - for gaps from 2 to 10 mm, it is very convenient to use and provides almost complete sealing.
Installing plastic windows, we spend a lot of money, while we hope to get warmth, comfort and beauty in the house as a result, especially when the cold season comes. But with the advent of winter, the windows suddenly become covered with numerous droplets of moisture and you see that the plastic windows are crying, you don’t know what to do. As a result, only unnecessary problems appear: puddles form on the windowsill, dampness appears in the house, and sometimes even worse - mold and fungus on the slopes.
Even if you wipe the window dry very carefully, water will still appear on it, sometimes trickling down onto the new window sill, leaving streaks and small puddles. What can I say, the phenomena are very unpleasant.
Faced with the problem of weeping windows, many of us begin to accuse manufacturers of cheating. That is why it is first of all necessary to dispel the myth of poor quality products. It is a paradox, but still, the fact that plastic windows are leaking is a confirmation that they are installed in accordance with all requirements: the windows are completely sealed and reliably protect your home from cold air entering inside. So how do you understand why windows are crying, what is the reason and how to deal with this problem?
There is a widespread belief that they only get wet, but this does not happen with wooden ones. This is not true. Any modern window under certain conditions (we will consider them below), they cry, regardless of the material from which they are made - wood or plastic. Of course, wooden Finnish windows, which have double frames, get wet less than, for example, single plastic or wooden euro windows. The reason for this is not at all in the binding material, but in the fact that two-frame structures are distinguished by higher thermal insulation properties.
Another example can be given: the old Soviet wooden windows, unlike the plastic ones that are fashionable today, almost did not leak. However, here also the material is absolutely irrelevant. If old windows are provided with high-quality seals in the porch, and all gaps between window frames and glass are removed, then these old windows will also start to get wet, and even more than plastic ones. Why do plastic windows get wet? Why does condensation appear on them?
Condensation on windows is usually caused by a number of reasons. The main reason is the increased humidity in the room. In winter, the temperature on the surface of the plastic window drops significantly and often reaches the dew point. Experts call this the temperature at which air, which has a certain initial temperature and relative humidity, can no longer absorb moisture. We encounter the dew point every day. For example, when you get out of the shower, you can see that the mirror in the bathroom is completely fogged up, or in winter, when you enter a warm room from a frost, glasses usually fog up immediately.
Why is there high humidity in the room? There are many reasons for this. Moisture is always released in the kitchen while cooking, drying and washing clothes, showering or hot bath, using the toilet. Located on the windowsill houseplants or an aquarium in a room are also sources of moisture. The person himself, in addition, when breathing, usually releases about 50 g of water per hour.
In addition, the cause of condensation on plastic windows may be as follows:
- conducting construction work or apartment renovations using wet processes such as painting walls with water-based paints, plastering work, pasting walls with wallpaper, whitewashing ceilings, etc .;
- various redevelopments in the house, which were independently carried out by residents without taking into account design standards, in violation existing system ventilation, as well as the demolition of interior partitions.
Ventilation
Often the reason why condensation on plastic windows is incorrect or faulty ventilation in the house. In apartments, ventilation systems are arranged in this way: an exhaust hood in the bathroom or toilet, as well as in the kitchen. Over time, the hood can simply become clogged with debris, which often accumulates here, and fail. In addition, plastic windows have a very high degree of tightness, and this prevents the penetration of street air into the room. As a result, the heat exchange in the room changes dramatically - the stagnant air of an unventilated room comes into contact with the cooled window glass, on which condensation forms.
This problem is especially acute in rooms with increased activity. First of all, the kitchen can be attributed to such premises. It is here that many multifunctional household appliances are located, in addition, it is often located next to the bathroom. In such areas, it is clear why plastic windows are leaking.
Often, residents of the upper floors of houses face a problem, since dirty, moist air penetrates through the holes from the apartments below. Of course, windows on the first floors also often leak, since dirty air comes here from the basement or through the floor slabs. To avoid strong condensation on plastic windows, it is enough just to equip ventilation holes in the apartment with forced ventilation fans with check valve. In fact, the houses that were built according to the SNiPs of the USSR are designed for the fact that the air flow into the premises will be carried out through the cracks in the windows (principle supply and exhaust ventilation). Sealed plastic windows practically do not allow air to pass through, which makes natural air flow impossible. Because of this, moisture accumulates in the apartment, which later falls as condensate on PVC windows, and in severe frost on aluminum frame frost is formed.
Heating
The system plays a very important role in the problem of condensate. central heating. Radiators must be serviceable and quite powerful. In another case, the apartment may have insufficient heat transfer and low temperature. Batteries must always be strictly under the window. It should be borne in mind that heating radiators perform very important function- they heat the window opening. If you install too wide above a heating radiator, this can lead to convection obstruction warm air from the battery, in connection with which, the moisture content will increase. Make sure that the radiators are not cluttered with foreign objects. Often, curtains and curtains in apartments touch the window sill, which is why it does not enter the window opening. enough warm air.
How to deal with condensation on windows?
The best way to resist the formation of condensation on plastic windows is to achieve a uniform distribution of humidity and air temperature in the room. According to sanitary and hygienic standards, optimum temperature air should be at least twenty degrees Celsius, and relative humidity - not higher than 45%.
When the windows cry what to do with the room? Do not forget to air it regularly, at least three times a day. It is worth noting that in winter period, it is better not to use the micro-ventilation mode. To avoid freezing window fittings, as well as hypothermia of the slopes, it is better to fully open the window for about 5-6 minutes. This time is enough to remove all excess moisture, while the heat from the room will not have time to leave.
http://www.youtube.com/watch?v=Oak0zSRCzIQ Video can "t be loaded: Fighting condensation on plastic windows (http://www.youtube.com/watch?v=Oak0zSRCzIQ)
If you are only planning to install plastic windows, choose window frames with the thickest possible profile to reduce penetration. You will lose, or rather, not gain, just a couple of centimeters of the window sill, but you will definitely have much less hassle. In addition, it is worth ordering a triple, not a double-glazed window. Also suitable double with one more additional glass. In this case, you will have absolute sound insulation, and glass not even in forty degrees of frost.
If you have already installed plastic windows, then the problem of leaking windows, what to do, can be solved only with the help of forced ventilation. In other words, it is necessary to somehow organize air exchange in the window niche.
How to do it? Below are a few simple ways
1 way - romantic (very easy and cheap)
In winter, when the street is very very coldy, put on the windowsill, as close to the glass as possible, several candlesticks with slowly burning candles. Thick decorative candles are best suited. For the whole winter, just a couple of candles per window will be enough for you. The costs are quite small, but the result is very significant. Of course, this is not about the heat that you get when burning a candle, but about the convection of air that is formed during the combustion process. In addition, a candle is very useful for plants on the windowsill, because it drives carbon dioxide for them, and, as you know, for indoor flowers is a favorite delicacy.
2 way - advanced
If there are no plants on the windowsill, and you are a fan of witty technical solutions and like to make something with your own hands, then try making convection screens. These are such narrow plates that transport warm air from the radiator to the window niche. The plate should be fixed at an angle of 30-60 degrees to the window sill. So part of the warm air will be forcibly directed to the glass. If you show imagination, then such screens can easily be made an original piece of decor. It should be noted that this is a rather laborious method.
3 way - the easiest
Almost every home has fans. As a rule, they work only 3-4 months a year when it is hot. But during the period of cold weather, they can be used again for their intended purpose, because in the window niche you just need to create any movement of air. So you can just install minimum intensity blowing and, if possible, install the fan in such a way that it blows several windows at the same time.
4 way - chemical
Buy at the auto cosmetics store any anti-fog aerosol that is used to treat car windows so that they do not get wet. Treat apartment glasses with such an aerosol. Remember to thoroughly wash and dry the window first, and then apply the anti-fogging agent to it. This will lower the dew point of the glass a little. True, this method cannot radically solve the problem. In addition, such aerosols are quite expensive and contain many specific chemical compounds and substances.
5 way - exotic
Stick a thin conductive film or foil around the perimeter of the window and apply low voltage (about 12-24 volts) to it. It will warm up that part of the window that is most prone to freezing. In other words, make glass with electric heating, like in a car.
So, if you carefully make sure that the technology for installing plastic windows is fully observed, choose a high-quality design, and then constantly monitor the level of humidity in the apartment, then you will definitely never again see excess moisture flowing through your plastic windows.
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 condensate on the glass in the cold season. Why do plastic windows sweat in winter and how to fix such a problem?
Causes and consequences of fogging windows
The cause of fogging windows is hidden in physical properties water. Being in a gaseous state, it is imperceptible, 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 plastic windows.
The cause of moisture settling on the glass is high humidity. If the windows began to fog up from the inside, there can be only one reason - this is a defective double-glazed window. This element of the entire system must be sealed, and if this condition is violated, water vapor enters, where it settles on the inner glass when cooled. This problem is eliminated by replacing the double-glazed window, the frame can be left.
However, most often condensation forms on outer surface window. Why do plastic windows sweat in winter and how to eliminate such a factor? There can 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 occurrence of worse phenomena:
- Freezing windows and the formation of frost on them.
- High humidity is the cause of mold, rot and fungus.
- Water and low temperatures gradually destroy the foam in the gap and break the tightness of the entire system and the house.
Constant fogging of windows can lead to mold growth What to do with such negative influence 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 that evaporate a large number of moisture.
Window adjustment
You can make sure what is the cause by making a simple inspection of the entire window. The first thing to do is to check the correct adjustment of the flaps and the degree of their locking.. This is done in the following way:
- 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 placed 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 bottom loop.
To adjust the sashes, tighten the bolts located on the bottom hinge The degree of pressing is regulated by eccentrics at the ends of the window, as well as by tightening the pressure plates.
Transfer to winter or summer mode carried out with the help of eccentrics Do not forget about the seasonal adjustment of windows. To do this, the regulators turn the marker inward for the summer, and towards the street in the 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 double-glazed window.
In this case, to normalize the circulation in the window sill, you need to drill several holes that will ensure normal access of heat to the glass.
Holes in the window sill allow warm air to heat the glass You also need to pay attention to the grilles covering the heating radiators, perhaps they also interfere with air exchange.
slope finishing
If the window was installed with violations of technology (leaky gaps, the frame has moved), then you should contact the installer. Installers are obliged to fix such a problem free of charge.
An independent attempt to seal the gaps may not correct the situation, since the double-glazed window was initially installed incorrectly.
Finishing and insulation of slopes prevents fogging of windows Another thing is with slopes. If finishing has not been done, it must be carried out immediately, otherwise it will lead to total destruction polyurethane foam in the gaps. In order for the windows not to cry, it is best to additionally insulate them using heat-insulating material ( mineral wool, polystyrene or foam plastic).
accessories
Quite often, windows cry due to poor-quality or worn fittings. All mechanisms must function normally and smoothly lock the sash with normal pressure.
Damaged seal must be replaced The seal must be carefully inspected. It should be elastic, without tears and cracks. If there is damage, and elasticity is lost, proceed to replace it.
Ventilation
The ventilation of the room must be approached very carefully. This is especially true for rooms with a high level of humidity (kitchens, bathrooms), where windows sweat most often in winter.
After all, plastic windows completely seal the room and make it difficult for air to enter from the street. You can solve the problem of air exchange in the following ways.
Verify existing ventilation for contamination. This can be done by lighting a candle near the channel exits. If the light does not deviate, then the hood does not work. The grids are removed and cleaned until normal functioning is restored.
However, apart from exhaust system ventilation must also be present. This issue is resolved by setting ventilation valves on the windows.
Forced ventilation can be provided with a valve built into the handle Today there are modern supply systems, installed in the window handle, they do not spoil appearance and provide an adequate supply of fresh air.
With security normal level ventilation is eliminated and the problem of high humidity.
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 installed in the living room, then it will not provide proper heat conservation.
Insulating glass with film will not solve the problem of cold You can fix the problem by insulating the slopes and applying an energy-saving film to the glass. But these measures will not ensure the preservation of heat in full.
Humidity level optimization
As mentioned above, this phenomenon can be eliminated by ensuring the normal ventilation of the rooms. However, if this does not help, then you can mount dehumidifiers under the windowsill. Such cartridges are inexpensive, and their efficiency is quite high..
Recent renovations can contribute to the increase in humidity in the room. Big square plastered surfaces evaporates a huge amount of moisture, which ventilation cannot cope with. This is a temporary phenomenon and as the walls dry, the humidity level returns 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 problems with fogging.
PVC windows are installed in my house. In the cold season, droplets appear on their surface, because of this, double-glazed windows sweat and flow. This is not the most pleasant phenomenon, so I decided to find out why plastic windows sweat and how to fix such a problem with my own hands. I share my findings below.
Top 5 Reasons
It is possible to find out why plastic windows sweat in an apartment only after a detailed consideration of the concept of "tightness". Double-glazed windows help to increase the thermal insulation in the room, so they are considered to be of higher quality than wooden ones.
Unlike wood, PVC structures make the room more airtight, they pass less cold air from the outside and, in fact, do not release warm from the inside well. Therefore, the windows sweat very much if we add poor ventilation and malfunctions of the heating system to the above factor.
Why do plastic windows sweat in winter? This is due to the fact that condensation forms on the glass only when the temperature inside is below +18 °C. This situation is usually observed in heating period when the air outside is much colder than indoors.
In addition to tightness, heating quality and indoor air convection, there are 2 more common reasons why a plastic window sweats from the inside:
- improper microclimate in the room;
- errors in the production and installation of windows.
About the microclimate and ventilation
As mentioned earlier, PVC windows are completely airtight, which means that the air in the room can only circulate with the help of good ventilation. Before through the cracks in wooden frames air could easily pass through and the humidity in the room was always naturally regulated.
Now we do not have such a source of ventilation, and, therefore, the humidity of the air is growing all the time. A certain amount of water vapor (humidity) is always present in the premises, and at a certain temperature it becomes so thick that it begins to settle on the windows.
Droplets appear on the coldest surface of the room, most often it is glass.
The main sources of indoor moisture that cause our windows to sweat are:
| Image | source of moisture |
 |
Reason 1. Water in building materials
After repair, a certain amount of moisture always remains on the wallpaper, plaster and slopes. Therefore, mold and fungus can appear on the walls.
|
 |
Reason 2. Human factor
|
 |
Reason 3. Pets
|
One of the most probable causes why plastic windows sweat can be called high humidity and poor ventilation.
Ways to solve the problem
What to do in such a situation? Since the options why sweat plastic double-glazed windows there are several, and there are many ways to solve it:
- reduce humidity;
- increase the heating of PVC windows;
- normalize ventilation.
Method 1. Reduce humidity
I propose a solution to the problem in 2 steps:
- Remove excess moisture from the room using a special device that absorbs water vapor (sold in large construction stores, the price is available).
- Thoroughly ventilate the room.
It is the second step that will allow you to constantly adjust the amount of moisture in the room. How to properly organize ventilation? There are three ways:
| Image | Instruction |
 |
Long-term ventilation
Leave the sash open all day.
|
 |
intensive
Open all windows wide open for 15 minutes. Moist air will change to dry. In this case, there will not be a large loss of heat. |
 |
Cardinal
Arrange the maximum draft: all windows and doors wide open for 5 minutes. |
Modern windows are designed to save us from cold, noise and problems with drafts. But they, as practice shows, are very sensitive to conditions environment and just about anything, they start crying. Why does condensation appear on windows and how to get rid of it?
A very common winter problem is condensation on windows, or rather on inside window glass. Metaphorically, this is referred to as “windows fogging up” or “windows crying”. This means that the window glass is covered with moisture droplets, and if this happens regularly, then the water gradually flows down from the glass to the window sill, and from there to the floor. At worst, always wet windows provoke the appearance of mold on the walls and ceiling, which is extremely difficult to get rid of.
Why windows fog up
Let's figure out why the plastic windows in the apartment fog up. Water droplets that settle on the windows are moisture from the air. In the air, of course, it is contained in a gaseous state. What causes it to fall out in the form of condensate on the windows?
The fact is that air can only hold a limited amount of water. There is a limit after which water will begin to "poured" out of the air and settle on surfaces. This limit depends, first of all, on the air temperature - the warmer it is, the more moisture it can contain. For example, a cubic meter of air at a temperature of 25 ° C can hold 22.8 g of water, and if it is cooled to 0 ° C, it can hold only 4.8 g, and “get rid of” the rest: the excess will turn into condensate.
Imagine that your room is 25°C and there are 15.9 g of moisture per cubic meter of air. This is about 70% of the possible 22.8 g/m3, i.e. the relative humidity in our example is 70%. It would seem that there is no excess, on the contrary, the air can hold a few more grams of water, but why then do the windows in the apartment fog up? The matter is that in the winter your windows are cooled by street air. The temperature of the window glass drops below 25°C, the air in this place becomes colder and its ability to contain water decreases. Even 15.96 g/m3 is too much for him. Excess drops out as condensate - that's why windows cry.
How cold does glass have to be to cry? Critical temperature equal to or below the dew point.
The dew point is the temperature of a surface above which condensation does not occur on that surface.
| Temperature air |
Relative humidity | ||||||||
| 30% | 40% | 50% | 60% | 65% | 70% | 80% | 90% | 95% | |
| -10°С | -23,2 | -20,4 | -17,8 | -15,8 | -14,9 | -14,1 | -12,6 | -10,6 | -10 |
| 0°C | -14,5 | -11,3 | -8,7 | -6,2 | -5,3 | -4,4 | -2,8 | -1,3 | -0,7 |
| +5°С | -10,5 | -7,3 | -4,3 | -2,2 | -1,1 | -0,1 | +1,6 | +3,3 | +4,1 |
| +10°С | -6,7 | -3,2 | -0,3 | +2,2 | +3,2 | +4,4 | +6,4 | +8,2 | +9,1 |
| +15°С | -2,9 | +0,8 | +4 | +6,7 | +8 | +9,2 | +11,2 | +13,1 | +14,1 |
| +20°С | +1 | +5,2 | +8,7 | +11,5 | +12,8 | +14 | +16,2 | +18,1 | +19,1 |
| +25°С | +5,2 | +9,7 | +13,1 | +16,2 | +17,5 | +18,8 | +21,1 | +23 | +24 |
| +30°С | +9,5 | +13,9 | +17,7 | +21,3 | +22,5 | +23,8 | +26,1 | +28,1 | +29 |
Dew point determination
As you can see, the dew point directly depends on the temperature and humidity of the indoor air. In our example, at 25°C heat and 70% humidity in the room, it is enough for the glass to cool to a temperature of 18.8°C for condensation to form on it.
You may have noticed that condensation on plastic windows falls first on the bottom of the glass. because of design features This is the part that cools down the most.
However, if the window glass at the same 70% humidity is at least a degree warmer, or if the humidity at the same window temperature is 10% lower, then condensation will not occur.
Having understood the reasons, we can answer the main question of the article. So, what to do if there is condensation on the windows? It is necessary either to raise the temperature of the window, or to lower the humidity of the air, and in some cases (however, infrequent) it is necessary to do both.
window heating
Glass inside the room, as you understand, the colder, the lower the temperature outside and inside the room. But since we cannot influence the temperature outside the window, all that remains is to adjust the temperature in the room.
Low room temperature may be due to non-compliance by utilities. If you feel that the apartment is cold, then take temperature measurements. Remember that you need to do this in the center of the room at a distance of at least one meter from heating appliances. If measurements show irregularities, contact management company. In the meantime, they will not take action, they will have to save themselves: they can help when the plastic windows in the apartment fog up.
It may also be that the temperature in the room corresponds to all kinds of sanitary and building requirements, but for some reason warm air does not reach the window glass and becomes the reason why plastic windows cry. For example, a too wide window sill may prevent warm flow from a battery. It serves as an obstacle in itself, and indoor plants or other items, which, as a rule, are located in abundance on such a window sill (otherwise, why take a wide one?), Make it even more difficult for warm air to enter the window. Heavy blackout curtains can also be included in the list of such obstacles.
Another common cause of window freezing is the insufficient thickness of the double-glazed window. Modern plastic windows are single-chamber and two-chamber. The former, as a rule, are cheaper and transmit sunlight better, but freeze faster. If you are going to install a new window, weigh the pros and cons different types double-glazed windows.
lower humidity
The solution to this problem would also not hurt to start with to find out what, in fact, is the humidity in your house. The norm is 40-60%, it is these figures that should be guided when we want to reduce humidity and forget about crying windows. Here, however, it is important not to overdo it: air with a humidity of 10-20% will be too dry and can cause discomfort.
The easiest way to reduce the humidity in the house during the cold (we emphasize) season is to regularly ventilate the apartment. Cool air from the street, when it enters the room, heats up, its ability to hold water increases, and relative humidity (the percentage of moisture per cubic meter of air) decreases. In such air, there is enough space for water, it “absorbs” it, and does not throw it out in the form of condensate on the windows.
Of course, lowering the humidity is only side effect from ventilation, the main objective who to let into the room Fresh air in an amount sufficient for a comfortable stay of people. In general, airing in winter, we kill two birds with one stone: we get fresh air and eliminate the cause of condensation on the windows. However, you need to ventilate properly.
If you contact your window company with the question “Plastic windows are crying, what should I do?”, then most likely you will receive a recommendation to open the sashes more often for the so-called micro-ventilation. However, this, firstly, is not always convenient: in cold weather, even from a small hole it can noticeably blow. Secondly, it is almost meaningless: the effect achieved by fifteen minutes of airing disappears in half an hour. Thirdly, such ventilation is fraught with freezing of window seals, which leads to loss of tightness when closing.
Opening the window wider - in summer - is also not possible for obvious reasons: we will get cold and drafts (we are talking, of course, about the cold season, because fogging of windows in an apartment is an autumn-winter problem).
A more suitable way of ventilation in this case is compact ventilation device. The breather is installed on the wall and supplies fresh air in a volume sufficient for 4 people (120 m3/h). The important thing is that the breather heats the supplied air, automatically maintaining the temperature of the air jet set by you, regardless of the temperature outside the window. So there will be no blowing from the breather. In general, proper ventilation will relieve stuffiness, condensation on windows and dampness. One of our clients shared personal experience solutions to a similar set of problems, you can read
