标准GBT 8478-2020铝合金门窗有采用室外火灾温度曲线，大意是680度，如下：
方法引用自GBT 38252-2019 -> GBT 26784-2011 ->EN 1363-2-1999附加耐火测试，说明是：
在某些实际情况下，建筑构件的受火条件不如它们在防火分区内部的受火条件严酷。例如，建筑物四周的墙体，这些墙体可能受到建筑室外火焰或者从窗户出来的火焰的烧灼，因为室外火灾存在大量的热量扩散现象，所以应给出较低水平的受火条件。因此采用室外火灾升温曲线评价构件的耐火性能。
In some cases elements may be exposed to conditions which are less severe than when the element or structure is exposed to a compartment fire. Examples of this are walls at the perimeter of a building which may be exposed to an external fire or flames coming out of windows. There is also a need to ensure that the nature of fire protection is such that the re-entry of the fire into the building is prevented. Because of the nature of external fire with the additional possibilities for heat dissipation a lower level of heat exposure is given.
待进一步研究定义680度的依据，欢迎交流。