The secrets of a good window: the window profile

What is a window profile?

Initially it is a raw material – polyvinyl chloride, which comes in the form of a powder. It goes into processing only after expert reports from the incoming inspection labs. The raw material’s humidity, flowability and density are checked and, if the parameters are perfect, the raw material is sent to the mixing shop. A large number of machines and auxiliary tools are involved in the process of creating of double glazed profile, which not only forms the desired blanks, but also removes excess air impurities from the main mass and, through a multi-stage forming, cooling and drawing process, gives the profile a regular, non-deformed shape. 

The result it is a fully airtight, metal-reinforced plastic structure, which forms the load-bearing base of the insulating glass unit and ensures the normal functioning of the upvc window. This is the window profile. The stiffness of the frame and its overall quality influence on:

• The strength of the windows
• Tightness
• Stability
• Usability and operation of sashes 
• Durability and service life

Key stages in window profile production 

The outer walls of the profile are on the surface. Inner cavities, fixings, fittings are invisible to the eye. Accuracy of execution is important, and can be achieved only in production by means of factory assembly on professional equipment. In the tool shop there are a number of machining manipulations (turning, grinding, etc.), which are measured in microns, not even in millimetres. But it is precisely these manipulations that concern the reinforced parts of the profile. Before sending the upvc profile for further assembly, they undergo quality control to check their durability (by applying pressure to the profile) and geometry (according to a given drawing) and at the end we have what will be a complete double glazed window frame in just a few assembly steps. In production, every couple of hours specialists perform instrumental control, colour checks, slot functionality and impact resistance checks. Such filigree work on profile production ensures high quality of the final product, i.e. the whole insulating glass unit.

Mounting thickness and number of chambers in profile

Mounting width of a profile is one of the main indicators that defines dimensions of a upvc window frame. This technological depth of a profile of a window also influences durability of all window construction, on ability to hold not only specific weight of a window, but also all accompanying loads connected with constant operation, and loadings connected with natural and mechanical influences, including negative ones. 

Window profiles in double glazing are divided into three classes and it is important to understand that profile sub-types within these classes do not differ from each other. It is also worth saying that all profiles comply with certain technical standards and are all of high quality, as they have not been extruded somewhere in underground garages for a long time. However, in certain climatic conditions it is recommended to install one or another type of profile. In harsh weather conditions, for example, more protection and higher thermal insulation is needed, so the profile class should also be higher. The thickness influences the thermal properties of the frame (the thicker the frame the warmer is) and the transmission distance of the cold around the frame on the linings. This is especially critical in concrete walls with shallow quarter windows. But in a wall with thick external insulation it has practically no effect. Therefore, when measuring and ordering double glazing, the specialist looks at the architectural features of the building to select the correct profile class. 

Let us examine the window profile classes:

• Economy. 58-60 mm. Accommodates 3-4 chambers with a high coefficient of heat transfer.
• Standard. Number of chambers from 4 70 mm. It contains 5 or 6 chambers.
• Premium. 80 mm. In such profile it is possible to insert from 6 to 8 chambers. It is distinguished by a weak coefficient (no more than 1,05 W/(m2*K).

Why is it necessary to choose a profile responsibly?

An irresponsible approach to the choice of plastic window profiles is fraught with lots of unpleasant consequences. The customer will buy a product that does not match the technical characteristics of the project in the best case scenario. The most common example is when a basic 60 mm profile is taken for glazing a house in a cold region, although in local climatic conditions the depth should be no less than 80 mm.

The profile is important, but its brand or width alone does not describe the finished window. Glazing, hardware, opening configuration, manufacturing and installation can all change the final specification. Our guide to why window specifications matter more than brand names explains what homeowners should compare beyond the profile itself.

In addition, in an attempt to save money you may be the owner of a frankly low-quality or counterfeit products, which will be out of date after a couple of seasons. The result: blowing, noise, heat escaping to the outside, difficulties with opening and closing. That is why we always recommend choosing a profile consciously and ordering windows only from certified partner companies who can guarantee the quality of production and installation of structures.

The profile is important, but it is only one part of the finished window. Before ordering, it is also worth checking how the sash sits in the frame, how smoothly the hardware operates, what glazing is included and how carefully the window has been fabricated. Our guide to how to spot a high-quality window before you buy covers these practical checks in more detail.