Principles to be followed when designing system windows and doors 

The design of system windows and doors must comply with the following principles:

(1) Principle of equal service life. When window and door components reach the end of their service life, the life of the entire window can be extended with one-time maintenance (such as replacing sealing strips, plastic parts, hardware and other consumables) without compromising the performance of the entire structure.

Excessive emphasis on the characteristics of one component while ignoring the scientific combination of all the details will only lead to an imbalance in the system. For example, if high-quality European fittings with a service life of up to 50,000 opening cycles are used (service life of more than ten years), but low-quality seals with a service life of only 2 years are selected, this will lead to problems with tightness, and the sealing tapes will have to be changed every two years. Likewise, using thermally broken aluminum profiles in combination with single glazing will significantly degrade the overall thermal insulation properties of the window.

(2) High performance principle. The progress of window and door systems is reflected in the pursuit of superior performance. To ensure exceptional performance, high-performance materials should be used as much as possible, unless this conflicts with the principle of equal service life. Fluorocarbon spraying technology (PVDF) for surface treatment of aluminum profiles has excellent resistance to friction, industrial and marine corrosion, as well as ultraviolet radiation, maintaining the original appearance of the coating for 20 years. EPDM seals with high weather resistance ensure maintenance of performance properties without aging and destruction for 20 years.

(3) The principle of high value for money. There is of course a valuation issue involved, but when investing in any product, technical feasibility, technological feasibility and economic feasibility must be taken into account. Currently, there are many types of system windows, and customer choice is not always based solely on performance indicators. Therefore, when designing system windows, it is imperative to take into account their profitability. For example, when designing window types, Chinese designers usually prefer to divide the transparent part of an external window into many segments, and the sizes of these segments are often chosen arbitrarily. This separation has not made a big difference for conventional windows in the past and has not caused a significant increase in price, but for passive houses it can lead to serious consequences such as reduced performance, increased costs and difficulties in maintenance.

— Publishing house of the mechanical engineering industry, “Illustrated design and production of energy-saving system windows”