Glazings

The glazing is a construction of two or more glasses, kept apart by a special spacer that is hermetically closed, isolated. The options for combining different types of glass in one common construction are unlimited. The thermal insulation properties, the sound protection and the appearance of the glazing all depend on the correct and most appropriate combination of glazings.

There are several aspects at the base of the glazing of each and every different building, namely:

• Thermal insulation;
• Solar and light control;
• Acoustic insulation;
• Security and safety;
• Architecture, design and decoration.

Important criteria for glazing evaluation:
U: Heat transfer coefficient – generally, this coefficient measures the quantity of energy that goes through given area of the glass per unit of time, evaluated with a difference of 1 Kelvin. The lower the values of this coefficient are, the lower the heat loss through the glazing is.
SF: Solar factor (an indicator for the total amount of solar energy that goes through the glass) – important for air conditioning. The lower solar factor means that there is less solar heat coming through the glass, thus cooling is easier.
TL: Transport light  – indicates the percentage of light quantity that goes through the glass in comparison of the entire rayed light. The high percent of light transport is an important condition for the comfort in one’s home.

The glazing of a building can have between 70% and 90% influence on the total energy cost. That is why it is preferable for the glazing to possess the following characteristics:

• Low solar factor;
• High light transmittance;
• Low U-value.

Thermal insulation

When looking at the question about the thermal insulation it is with prime importance to observe the places where heat loss occurs in one building. Researches show the following information for the heat loss:

• Floors -9 %;
• Walls – 26 %;
• Roof – 24 %;
• Windows – 41 %

There are a few types of glass that due to their cladding (covering) can drastically influence on the heat transfer coefficient:

• Top 1.1 – Low emission (Ка) glass– glass with a high solar factor and transmits high level of sun warmth; at the same time the Ka glass has got a low coefficient of thermal conductivity. In this way the glass helps for heat retaining in the premises and does not reduce solar heat in any way. A very suitable and appropriate choice for north, east or shady facades.
• Advanced 1.0 (4 seasons) – this is the glass with low solar factor and low heat transfer coefficient. Results – limited heat transfer – either from the outside to the inside or the other way around. The Advanced 1.0 glass will help the cooling of any premises, because it does not allow their overheating, due to the low solar factor. The warming of the place will also be more effective – the low thermal conductivity does not let big temperature loss through the glazing. Advanced 1.0 glazing is suitable for south and west facades, as well as such with intensive sun-shining.
• Energy– it has got identical characteristics as Advanced 1.0, it is only distinguished by its lower solar factor. This brings to utmost reduction of solar heat access. This glass is extremely suitable for buildings situated in locations with longer period of sun-shining and the air-conditioning is of primary importance for the comfort. Besides the standard aluminium spacer, you may choose an aluminum one with black matt cover as well as PVC spacer in several different colours. The overall characteristics of the glazing can be influenced through implementation of PVC spacer (the so called “warm end”) into the glazing system – it has got better thermal insulation properties, more elegant design and does not allow any condensation on the edges of the glass.

Generally the filling of the middle area – between the hermetically closed glass, is through air. In order to achieve a significant improvement of the thermal-insulation properties, the glazing can be filled in with Argon gas – harmless inert gas. This is one effective and low cost solution for improving the benefits of this glazing, as a result the thermal-insulation values rise.

 

Sound protection

The sound protection of glazings improve by changing the thickness of a single glass – instead of 4mm, 5 or 6mm thick glass is used. The sound protection reaches its superior levels within triple glazing that combines glass with different thickness (for example 4+4+6 or 4+5+6), as well as with implementation of laminated glass (triplex). The triplex is a combination of two glass layers, that are tightly glued with a special sound-protective foil. This adds up one more advantage – so not only better sound protection but also if breaking – the glass stays stuck on the foil.