Feasibility of aluminium sliding doors and windows in Passive Buildings
According to the traditional theory, the aluminium sliding doors and windows is not suitable for passive buildings, because of the high thermal conductivity of aluminum alloy materials. However, we believe that aluminum window are worth popularizing in term of material strength and the material processing diffculty. If properly designed, the wide utilization of aluminum windows in passive buildings could be in line with China's national conditions and the development trend of the construction industry.
First, we believe that the aluminum window system is fully capable of satisfying passive construction.
Building requirements; second, the thermal expansion coefficient of aluminum alloy materials is much lower than Wood and PVC materials, which facilitates north-south transportation of materials; third, The corrosion resistance of the aluminum alloy material and surface treatment is much higher than that of wood Fourth, the bending strength and fatigue strength of aluminum alloy materials are much higher than PVC material; Fifth, the aluminum alloy material is relatively difficult to process and the yield is high. Various finishes, low processing equipment costs, and easy promotion. But aluminum window system The traditional problem is also fatal, that is, the high thermal conductivity of aluminum alloy materials, In most cases, window frame conduction can only be solved by broken bridges.
The length directly affects the thermal insulation performance of the aluminum window frame, so Quality directly becomes the core issue of aluminum alloy window system. But this is in the aluminum window system The traditional material link can be solved, after all, there are German companies such as Tylenol PA66 materials produced by the industry can meet the requirements of a certain environment and time, Window safety requirements.
We believe that in principle the aluminum window system can fully meet the requirements of passive buildings Requirements, but it is not appropriate to choose aluminum window system insulation bridge materials Oversized and long materials, 35 ~ 40mm is a reasonable range, so Can ensure the safety of the whole window in the case of overhanging installation, but only by 35 ~ 40mm thermal break bridge can not meet the heat transfer system of the whole window Number of requirements.
Therefore, we use the same aluminum External insulation material for window frame, through the joint work of thermal insulation broken bridge and external insulation of window frame Use, under the premise of meeting the energy saving requirements of the whole window K value ≤ 0.8, the maximum To a certain extent, the attenuation of the PA66 bridge material itself has weakened the strength of the entire window Effect, improve the service life of the whole window, and effectively reduce the aluminum alloy window system The cost of the system in the passive building field. The GM outside shown in Figure 4 The thermal insulation aluminum window system is fully satisfied through the combination of external thermal insulation and thermal insulation broken bridges. The indicators of the whole window in the field of passive architecture.