uPVC Window VEKA SL 82

There are two window opening directions possible: inwards or outwards. When you want to determine the window opening direction, you have to stand at the side where you can see the hinges. If you are standing outside the building and the windows open towards you, these are outward-opening windows. If, on the other hand, you are standing inside the building and the windows open towards you, these are inward-opening windows.

A glazing unit is a structure consisting of two, three, or even four panes of glazing separated from each other by a distance frame, sealants and vapour-absorbing gas (argon \ krypton). The thickness of the glazing unit is the overall measurement, from the outside glass surface to the inside glass surface. The average double glazing thickness is about 24 mm while triple-glazed windows are 42 – 48 mm in thickness on average. The number of panes in a glazing unit affects the improvement of the U-value parameter

The number of chambers in the window affects the thermal insulation of the window. The chambers keep air from circulating and in this way they create an additional insulating layer. Energy-saving (passive) windows most often come with a 6-chamber structure and a built-in depth of over 80 mm. Window chambers also increase the structural strength of a window and add to its overall stiffness

window gaskets prevent draughts and water from entering into your home. They are also a barrier for the outside noise and an effective way to keep warm air in – and thus, lower your energy bills. Two gaskets are necessary for the window to fulfil its function properly, while the central (third) gasket is not necessary. However, it has been proven that window structures with a central gasket are tighter, both in terms of air permeability and water-tightness, than structures without a middle gasket. Also, third gasket affects the improvement of the U-value parameter.

The walls of the window chambers have different thickness, which determines the class of the profile. The thickness of the profiles is defined by the PN-EN 12608: 2004 standard. Profiles can have three classes: A, B and C. This parameter specifies the wall thickness of the profiles. The Class A profiles have outer walls with a thickness of ≥ 2.8 mm. Class B ≥ 2.5 mm. The standard does not define any requirements for class C sections. Class A profiles are the best choice as they provide us with the best window insulation. However, while selecting the so- called “warm” windows, you should also pay attention to such elements as the number of chambers, gaskets, type of the fittings, warm edge spacer, and glazing unit.

It is one of the most important properties of windows and doors. It determines the safety of the entire structure, as it indicates the amount of pressure caused by wind that the window or door structure is able to resist without serious damage. The classification of wind-resistant windows is carried out in accordance with PN-EN 14351-1. The wind load resistance of the window is described by two symbols: the number (1-5) which indicates the pressure of wind applied to the product and the letter (A-C) which indicates the amount of accepted deflection.

It is the capacity to avoid water leakages under wind and rain at the same time. Leakage is defined as the appearance of uncontrolled water (other than condensation) on the inner surface of the product. Obviously, the doors and windows with good waterproof performance can effectively prevent water from entering into their internal structure and – as a result – ensure a longer service life. The classification ranges from Class 0 (no test) to Class 7A for windows and Class 3A for doors.

It is the measurement showing how easily air can pass through a window or a door. The European Standard regarding air permeability in windows and doors is EN 12207. It classifies windows or doors according to their capability to prevent air travel through the system. This capability is measured on a scale, from Class 1 (less tightness) to Class 4 (higher tightness). A window or a door system with a higher level of air tightness is more energy-efficient, as less heated air escapes through it. 

The window’s heat transfer coefficient. It informs you about the level of window thermal insulation. The Uw (U- value) shows how much heat will penetrate 1 m2 of a window in one hour, with a difference between the temperatures on both sides of the window of one degree. This means that the lower the Uw coefficient, the better the window’s thermal insulation is.