Window between the inside and outside of the building

“Window –  An opening in the wall or roof of a building, fitted with glass in a frame toadmit light or air and allow people to see out”。 This is a true and simple definition of window in the contemporary Oxford English Dictionary.

Each of us saw the look of the window, everyone knows the role of the window, but is it really so simple? The answer is No.
Modern windows, especially high-precision plastic windows, are a series of complex components combined into a refined system, can provide a variety of functions to meet the agreed requirements.
The most basic requirements for each window must meet the building-related technical specifications. In Europe, plastic doors and windows required performance indicators can be found in EN 14351-1+ A1:20101, when the wall installed in the window, it must meet the following functions:
1.Completely separate the space between the inside and outside of the building, so as to ensure a comfortable indoor environment;
2.Heat insulation, energy saving and improve living comfort, summer can reduce energy consumption of air conditioning refrigeration, winter can save heating energy consumption;
3.Sound insulation, reduce the disturbance of daily life and traffic noise, make the indoor environment more quiet, quiet rest and life, study;
4.Seal performance, reduce the amount of air into or out of the indoor comfort caused by the change, air leakage also means a large amount of energy loss; in addition, outdoor dirty air often entombed with dust and bacteria, seriously affect the cleanliness of the home;
5.Waterproof performance, even if the storm comes, it will not produce leakage phenomenon, which includes the window itself and the window and the wall of the connection seal;
6.Use the correct way to let the outside fresh air exchange to the indoor;
7.Allow a certain amount of daylight into the room, reduce lighting energy consumption;
8.Safety performance-structural and glass safety, to prevent the accidental fall of indoor children, to prevent the entry of outside unauthorized persons;
9.Bear the load, the self-weight of the window and the wind and other correct transmission to the wall structure to ensure safety;
10.Easy to clean and maintain, We think the current domestic popular so-called“Big fixed, small open” door and window optimization design, is not a people-oriented design, this low-cost design often poses a serious problem-you can’t clean the large glass on the outside in the current heavily polluted environment. After all, the popularity of small appliances such as window-cleaning robots is still very limited!

Select and determine the functional properties of the window you want-it is essential that the windows be used reliably over a long period of time, and that the performance level of the windows be reduced as little as possible over a period of years.
To some people, this sounds a bit mysterious, we will soon solve the puzzle.
Next, we will explain why windows must have some performance, because windows are“Fighting” every day!
The following picture shows the installed window, the challenge of every moment.

Image courtesy ift Rosenheim Guideline for installation of Windows and external pedestrian doors

Windows need to be considered to handle the following business.

The wind from outside acts on the glass and then passes to the frame, causing the frame to deform slightly, with coastal and high-rise buildings bearing the heaviest wind pressure, and reports of windows or glass missing are common during the annual typhoon season, need to check the window and glass anti-wind grade and installation quality is up to the requirements.
The frame absorbs much of the Sun’s heat from the sun’s rays, some of which is transmitted indoors to raise room temperature, and some of which is absorbed by the frame itself to raise the temperature of the material, the linear expansion of the material results in a change in size, which is reflected in the compression of the cavity structure or in the bending of the material itself; at night, a drop in temperature causes the profile to cool, will transfer the heat out of the room, while the material itself shrinking and shorter, day and night, constantly switching, the window is also constantly growing and shrinking.
In winter, when it’s -30 degrees outside and 20 degrees inside, windows need to be insulated and sealed! And hot summer and cold winter areas, how to reduce heat into the summer indoor will have more demand.
Traffic Noise from the outside, which is a common problem in big cities and continues to affect our health.

Rainwater from the outside, wind gusts and heavy rain during the monsoon season combine to test the strength and waterproofing of the windows. The windows are waterproof with 2 zones, one for the windows themselves and one for the connections between the windows and the walls.
Leaves and dust on the outside; good sealing will keep the indoor environment clean;
The wall structure acts on the windows by its own sway; (the sway of the building is always present, and the dampers installed in the super-tall Shanghai Center building in Pudong will reduce the sway of the building) ;

The push-pull force and torque generated by people opening and closing windows are transmitted through hinges to the frame, which is then transmitted to the wall structure;
Humidity and temperature indoors, and modern buildings with better insulation and more sealed doors and windows face a tricky problem: dew and mold on the windows’ surfaces or on the walls around them!

A preliminary solution:
1）Reasonable control of indoor temperature and humidity in a comfortable area, if the home has been to maintain high temperature and humidity, then no one can save you;
2) Considering the condensation on the inner surface of the window, an important index is the 10-degree isotherm, through the simulation calculation of the thermal performance of doors and windows can determine whether the minimum temperature of the inner surface of the frame is below 10 degrees, (in Shanghai area, if the ordinary aluminum window with broken bridge is very difficult to reach the standard) ! The 10-degree isotherm is a technical indicator that has been emphasized and evaluated in advanced passive housing construction.
3) In the installation must avoid the cold bridge or air leakage point, the lowest indoor wall temperature can not be less than 13 degrees, so that the wall can reduce the potential risk of condensation-mildew.

Use of sill boards at the bottom of outdoor windows, which are standard in the European market as well as insulating glass, and the benefits are obvious: sill boards eliminate water leaks at the bottom of windows, and the seal is long-term effective, but also can reduce the external wall hanging dripping scale.
Windows need to absorb and transfer different forces, to keep the functions of the window intact, if not, we need to file a complaint, and in the worst case we need to replace the window that meets our needs.
When we discuss the functions needed for windows, we must note that in addition to the quality of the windows, the quality of the installation is also very important, by experienced installers in the right way to install and seal, this way the window can maintain quality for a long time. In future chapters we will discuss how to properly and effectively install and seal doors and windows.

In addition to the above functions, the doors and windows are also the decoration of the building, the different series and many opening forms, as well as the rich color let the designer, the owner, the architect can play freely. Plastic doors and windows can be covered with plastic film to show a realistic wood grain effect; The existing product line can cover most of the market demand, from the standard inside-out inverted window to arc window or octagonal window, bay window, folding door, lifting sliding door, inside-out sliding door, etc. , we will discuss all open forms of plastic doors and windows in later chapters.