As a door and window curtain wall designer, there are often many people asking this question: How big should the outside window sash be? Is there any design specification, is there any national regulation? How to calculate the strength of the window sash?
There are many failure cases in window design, two common types: windows are too small and windows are too large. It is said that the window opening fan: the opening fan is too small, the result is poor ventilation, neither energy saving nor livable; the opening fan is too large, the result is inconvenient opening, and may even affect the operation when the window is opened due to the inconvenience of opening. Safety.
1, the window is too small - poor ventilation
The problem that the window opening fan is too small is relatively easy to solve, and various design specifications have a minimum of the ventilation opening area of the house. In general, a bedroom of about 12m2, a 600mm × 1000mm opening fan can meet the ventilation requirements; a living room of about 20 square meters, two 600mm × 1000mm opening fan can be satisfied; 4m2 of the bathroom There is a 600mm × 600mm opening fan is enough; the kitchen has a higher ventilation requirement, a kitchen of about 5 to 6 square meters, and a 600mm × 1000mm opening fan can also be satisfied. All of the above are minimum values. From a functional point of view, it is better to open the larger area, but the opening fan is more expensive than the fixed fan. Therefore, the designer needs to consider the window based on the positioning of the project based on the minimum value. Ventilation area. (Note: It should be noted here that the construction departments of some cities have introduced local regulations applicable to the region. For example, cities such as Shenzhen and Nanning have stipulated that the opening area of doors and windows is not less than 8% of the room area. Engineering design in these cities. It is necessary to pay attention to comply with these norms, and the specific provisions are not listed.)
2, the window is too large - open inconvenience
In fact, the national standards for the production of doors and windows do not specify the size range of the fan outside the window, but the airtightness, watertightness, wind pressure resistance of the doors and windows, as well as the service life of the hardware, opening and closing force. Size and other indicators. In other words, as long as the window you are making can meet these metrics, it is qualified. As for the concrete form of the specific design of these indicators, you do not care. Everyone can contend, continue to innovate, and make better products.
The problem that the window opening fan is too large is that the window sash is too heavy to cause the deformation of the hardware, and on the other hand, it is more prominent and sharp because it directly affects the use and safety. However, if it is conservative, the design is smaller and there is insufficient ventilation. In addition, the profile of the broken bridge aluminum alloy is generally larger. If the window sash is too small, the proportion of the glass is small, and the proportion of the profile will increase. The cost is not economical. Therefore, choose a moderate size. Here, it is related to the opening method: if it is flat inside, because the person can retreat indoors when opening the window operation, the problem is not outstanding; but if it is outside, the person needs to make an outward extension to the outside. The action of the body can complete the window opening operation, so it is very sensitive to the problem that the opening fan is too large.
The design recommendations are as follows:
Opening fan of casement window: width should not be greater than 700, less than 500, preferably about 600; height should not be greater than 1400, less than 900, preferably 1000-1200; use over-opening fan (too wide or too high), especially outside When opening, you must carefully consider the convenience and safety of opening.
(Now there is a new type of external window hardware, hand-opened window hardware, using this form of hardware, people no longer need to go out and just need to turn the handle easily to open and close the sash. As long as the sash profile is strong enough, the total weight of the sash does not exceed the bearing capacity of the hardware, which can exceed the limit of the opening width of 600mm. There are more advanced electric remote control windows.
Need to explain is the height: when we pay attention to the problem of too large windows, we often only pay attention to the width, in fact, the height is also very "fatal." For a general outer casement window, the height of the window sill is higher, the higher the sash is, the higher the position of the opening handle is, and the manipulator can be in the process of “stretching the arm → leaning over”. The height reached is showing a downward trend. Therefore, the window sash is too high and the handle is too high, which will increase the inconvenience of operation. For ordinary people with a height of 1.6 to 1.7 m, the height of the arm is about 1.4 to 1.5 m. According to the height of 0.9 m of the ordinary window sill, 1.0 to 1.2 m is a reasonable height for opening the fan (see the figure below).
The above analysis is to set the opening fan at a height of 0.9m. When the low window sill of 0.6m height is encountered, since the lower fixed fan is uneconomical, the starting height of the opening fan will be higher than 0.9m. More need to carefully consider the height/width of the opening fan. In addition, the bay window of the low window sill has more safety problems, and it is better to use the inner flat to facilitate the user to open and close.
3. Indoor safety - neglected problems
There is also a problem that is often overlooked in the design of windows: the widely used aluminum alloy profiles of broken bridges have sharp edges and corners. If the window is flat inside, the height of the sash under the edge of the window is about 0.9m to 1.1m. The safety of children aged 3 to 5 years at the window is a threat - hit the head. There are two ways to avoid it: use the outer flat or flat open inner (inside flat + upper hanging) window, but the former should not be used in the upper level, the latter will increase the cost. Therefore, this humanized design must be combined with the positioning of the project. In some high-end mid-rise residential projects, the use of flat-opening inverted windows can enhance the value of products from the perspective of humanized design.
Conclusion:
Residential windows and doors are a seemingly simple design product, but because of the long-term use of the most extensive audience, the details of each engineering technology need to be carefully considered. "The details are the devil", this sentence is very appropriate in the design of the house, the design of the window is only one aspect, in the detailed design of the house, how much effort is not wasted.
