For the production of metal-plastic windows, a PVC profile with a multi-chamber structure is used. The presence of several sealed chambers in the profile reduces its permeability to heat, which in many ways provides a key advantage of a metal—plastic window - high energy efficiency.

But in the manufacture of such structures, holes are made in the profile. It would seem that this will break the tightness of the air chambers and reduce the thermal performance of the window as a whole. But in practice, it turns out that the presence of such holes is necessary — and their effective operation allows you to improve the characteristics of the window.

We will tell you about the moisture inside the plastic profile, its removal and the importance of high-quality drainage below.

Where does the liquid inside plastic windows come from

The holes that are made in the plastic profile are designed primarily for drainage — that is, for the removal of moisture. Where does moisture come from?

• One of the sources of moisture is condensate. Moist air can penetrate into the structure, while a decrease in temperature leads to condensation. Moisture that was previously in a gaseous state turns into droplets that settle on cold surfaces.
• The second source of moisture is precipitation. Yes, the metal-plastic window is effectively protected from moisture leakage: the fittings tightly press the sash against the frame, and the sealing contour increases the tightness of the structure. But it will still not work to completely get rid of the penetration of moisture through the sealer — especially with heavy rains, which are accompanied by gusts of wind.
• Finally, there is a possibility of moisture getting inside the structure when washing windows. If you use a large amount of water and do not wipe the window dry, some of the moisture will penetrate inside, bypassing the seal.

Yes, there will be a little moisture in any case — but the problem is that it does not go away from the inside of the structure. And the accumulation of fluid inside the profile can lead to undesirable consequences:

• Firstly, water has a high thermal conductivity. Therefore, the profile inside which the liquid accumulates rapidly loses its thermal insulation characteristics.
• Secondly, in the cold season, the situation is aggravated by the freezing of the structure.
• Finally, if there is a lot of liquid, when it freezes, it forms an ice plug inside the profile. When freezing, the water increases in volume, therefore there is a risk of deformation of the sash or incorrect operation of the fittings due to skew.

Other unpleasant consequences of moisture accumulation in a plastic window include:

• The appearance of an unpleasant smell
• Creating conditions favorable for the development of bacteria or fungi
• Corrosion of metal elements of fittings and fasteners

How does plastic window drainage work

It is almost impossible to avoid moisture getting inside the structure — yes, a high-quality window lets liquid through in minimal quantities, but it still lets it through. Therefore, moisture must be removed from the profile, and for this purpose a drainage system is provided in the window design:

• When making a window frame, several oblong holes are milled in its lower part.
• Horizontal imposts or other structural elements are equipped with similar holes.
• The holes are made through and must be cleaned of chips. This is a prerequisite for effective drainage: nothing should interfere with the free flow of moisture.
• Special caps can be provided to protect the drainage hole. They are installed after the installation of the window. The cap covers the hole from above, while leaving a clear space for water to flow out.

The principle of operation of the system is as simple as possible. Wherever moisture gets, it will gradually drain into the lower part of the frame — where drainage holes are made. Through them, moisture comes out, and the profile inside remains dry. At the same time, a small area of such holes does not allow large volumes of cold air to penetrate into the profile. Therefore, there is no need to worry about a decrease in thermal insulation characteristics.

How to take care of the drainage holes of a plastic window

Moisture will escape from the plastic profile through the drainage holes only if the system is maintained in working condition. Very often, owners of plastic windows neglect basic care — and as a result, the holes are completely or partially blocked. Dust, plaster or small debris gets inside — and the drainage efficiency gradually decreases. Water accumulates inside the profile, and this reduces the thermal insulation characteristics of the window.

To avoid this, twice a year — with regular maintenance of the window — you need to pay attention to the drainage system:

• First, we wash the window from the outside, then open the sash and wipe the inner surfaces. The less dust and debris there is, the less likely the drainage grooves will overlap.
• Carefully clean the drainage holes on the inside of the frame. It is convenient to use a wire or a toothpick for cleaning.
• Remove the decorative plugs from the outside and repeat the cleaning.
• It is advisable to use a vacuum cleaner to remove fine dust.
• After cleaning the drainage holes, do not forget to install decorative caps in place.

Regular cleaning of the drainage holes of a plastic window does not take much time and does not require special skills. But you should not neglect it — 5 minutes twice a year will allow you to avoid the accumulation of moisture inside the profile, followed by a decrease in thermal insulation characteristics.

You can order a high-quality professional installation of metal-plastic windows by following the link