The International Organization for Standardization (ISO) just published a standard that dictates a standard specifying a method to measure the solar heat gain of complete doors and windows.
According to the ISO’s website, the standard applies to windows and doors with various types of glazing — glass or plastic; single or multiple glazing; with or without low emissivity coatings, and with spaces filled with air or other gases — as well as those with opaque panels with various types of frames, shadings devices, and active solar fenestration systems.
The standard specifies does not apply to non-vertical windows, curtain walls, industrial, commercial, and garage doors. The ISO says it also does not include shading effects of building elements like eaves, heat transfer caused by air leakage between outside and in, the ventilation of air spaces in double or coupled windows, or thermal bridge effects at the joint between the window or door frame and the rest of the building envelope.
The 52-page document can be downloaded here for more information.
