The five most common façade glazing mistakes

Everyone who once took up the construction of a building dreams of designing a dream home. However, not everyone succeeds in doing this in the end. Maksim Frolov, head of the Guardian Glass technical support department, deals with the most common mistakes when designing facade glazing and helps to avoid them in the future.

Maxim Frolov, Head of Technical Support Department, Guardian Glass

Mistake № 1. Incorrectly selected glass thickness and distance between them

When creating a project, it is important to take into account the height of the building and the fact that the double-glazed windows on the first and thirtieth floors will experience different loads. Therefore, it is necessary to correctly select the thickness of the glass, as well as the width of the distance between them in the glass unit.

If too thin glass is selected, significant distortion may occur during operation, or the so-called lensing - a process in which glasses bend, including from a change in the volume of gas inside. This can happen due to changes in temperature outside, strong winds, heat treatment of glass, etc. In addition, due to the too small distance between the glasses in the glass unit, they can stick together, which ultimately will lead to visible defects and freezing.

To notice lensing, just look at the reflections in the glass outside the building. If trees, houses or any other objects change their geometry, then there is distortion. And the adhesion of glasses can be determined by characteristic spots in the middle of the glass unit - these are the so-called Newton rings.

How to avoid mistakes? Ideally, take into account all possible loads during design. At the stage of production of double-glazed windows, it is necessary to make it a rule to check the lensing of the glass in the assembled glass unit, if the short side of the glass unit exceeds, for example, 1.2 meters. Of course, sometimes they also resort to depressurization of the glass unit directly at the facility and correct the error, but such procedures are undesirable.

Mistake № 2. Incorrect selection of glazing from the point of view of heating technology

Despite the clear trend towards panoramic glazing, some designers still neglect or do not have the necessary knowledge about the mandatory norms of "Thermal protection of buildings". In 2018, our company developed a new version of the online glazing configurator, which many of our partners use today. However, it can be used to take into account the heat transfer resistance of only the central zone of the glass unit and compare their different configurations. The reduced resistance to heat transfer, required in the norms, is calculated taking into account the profile system, edge zones and dimensions. It is important to know that the reduced resistance to heat transfer of the structure, as a rule, is lower than the resistance of the central zone of the glass unit. Therefore, when providing a report from the configurator, you need to understand that real performance may be worse and even not comply with the standards.

To avoid mistakes, at the stage of production of double-glazed windows, carry out a verification calculation - for example, in accordance with GOST 54858-2011 - and, if necessary, change the formula of the double-glazed window to a suitable one. If you have already made a mistake, then when designing the rest of the building, consider additional heat loss for energy balance.

Mistake № 3. Incorrect design of opaque zones in facade structures

During the design process, it is often necessary to hide various opaque areas, floors or columns with translucent structures. The use of ordinary glass units for opaque areas can lead to irreparable defects. For example, there is a risk of thermal shock, depressurization or chemical condensation inside the glass unit, since the temperature of the internal glass can reach 150 degrees.

Therefore, in these areas it is necessary to use heat-treated glass, a metal spacer frame and silicone sealant, as well as provide for internal ventilation of such structures. In addition, we recommend giving preference to a single-chamber double-glazed window or single glass.

Mistake № 4. Neglecting solar protection with glass

To cool a room, you need to spend about 3 times more energy than heating. Therefore, the correct choice of solar control glass is very important.

Besides light, glass can bring a lot of heat, allowing it to pass through on hot summer days. If you do not provide for this effect when designing the facade, you can get a real steam room at the exit. In this case, internal blinds or curtains only partially restrain the heat, forming a thermal "bag" in the near-window area, which will still eventually heat the room. This is fraught with either increased air conditioning costs or high temperatures inside.

How can you avoid such a mistake? When designing, attention must be paid to the solar factor of the glazing, which indicates the total heat transmission. The smaller it is, the less heat from the sun will pass into the room. But do not forget about the norms of natural light. And when designing air conditioning, it is imperative to take into account not only the square of the room, but also the area and location of the windows.

Mistake № 5. Disregard for safety

Most of the requirements for safe glazing are advisory in nature, which is used by unscrupulous developers, saving on safe glazing. For example, installing panoramic windows in the entire wall, they use ordinary glass instead of laminated or tempered glass, which can injure a person when destroyed.

Here you can only advise not to save on health and safety and follow the established rules.

Source:https://fasady.pro/