Heat exchange coefficients of building glass types

Saving energy is very important in the construction industry today. To the extent that construction companies spend a lot of time choosing the right materials before starting construction. One of the materials and structures that should be given a lot of attention in its selection is the issue of building glass. The glasses in the building have the most energy loss, if they are not chosen correctly, so it is better to read the heat exchange coefficient table of the structural glass well before choosing the glass.

Designing the facade and choosing its glass is not a very complicated task, but when energy consumption is in the middle, everything becomes different. It is important to use the curtain wall glass structure and aluminum window and thermal break double-glazed windows. What kind of glass to use with what factors is much more important. Because the goal of architects in designing a structure, in addition to beauty and attractiveness; It is also a reduction in building costs.
Table of thermal coefficients of glass types

Certainly, at first glance at the above table, you have come across factors that may be ambiguous and questionable for you. For example: factors such as U-VALUE, LT and SF

If you don't know what these factors mean, don't worry; in this article, we explain what these factors mean and how they are used.

In the section below, you can see the table of heat exchange coefficients and energy savings by different glasses.

But the question is, how should we choose the glass for the interior and exterior of the building in order to have the least energy loss?

In this article, we will examine the heat exchange coefficient of building glass so that we can choose the best glass for the building using these coefficients.

LT factor; Lighting for the building

The LT factor refers to the amount of visible light transmission by the glass of the building.

This factor is commonly known as TV or LT and is defined for the visible light spectrum (wavelength 380nm to 780nm).

The higher this factor is, it means that the glass of the building is more transparent. LT is a very important factor in buildings where lighting is considered by architects and building designers.

So, if you are considering providing ambient light, you should pay attention to this factor and pay attention to it when choosing the right glass for the building. If you do not consider this factor in your choice, the light engineering in the building will be disrupted and you will not be able to provide the desired level of luxury for the environment. And you will have to use lamps and electrical appliances to compensate for it. And this means more cost
What is U-VALUE?

U value is one of the important factors in determining the amount of energy loss in the building. This factor shows how much energy the entire building consumes. The higher the UV value of the glass, i.e. the glass, the more energy it wastes, and this means more energy and costs.

For a better understanding and more detailed information about u-value and its effect on the heat exchange coefficient table, it is better to read the article What is u-value.

STC, sound resistance coefficient

STC is the sound insulation coefficient of glass and stands for Sound Transmission Class.

This criterion is used to calculate the effectiveness of sound insulation materials in reducing sound transmission between rooms. The STC unit is in decibels (dB) and this table shows how much sound and noise pollution is filtered by the glass.

The higher this value is, the more soundproof the glass is.
So, if your building is in a noisy environment, you should pay special attention to this factor.

Solar Factor or in the term (G-VALUE) is a factor that shows how much sunlight heat is transferred through the glass to the environment inside the building.

The lower this coefficient is, the less heat is transferred by the glass into the environment.

This factor is very important. For example, suppose you turn on the air conditioner on a hot summer day, but the environment of the house does not cool down. One of the reasons is the high SF in the glass and building materials, which causes the heat of the sun to enter the environment. It penetrates and changes the temperature of the environment.

So, if you live in a city with a hot climate and the weather is always sunny, it is better to keep this factor in mind.

UV factor

At first glance, you may ask yourself why the windows of the building should not let all the rays of the sun pass through them?

Sunlight has 3 rays called UV-A, UV-B and UV-C.

Among these, UV-B and UV-C rays are very dangerous for the skin, that's why they must be filtered. According to the international standard, the glasses that are produced in factories pass UV-A rays, but UV-B and UV-C rays, which are very harmful, are filtered.

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