DIN EN 50559/A1 E:2020 文件草案 电房间供暖、地暖、性能特征 定义、测试方法、尺寸和公式符号 德文版 EN 50559:2013/A1:2020
Draft Document - Electric room heating, underfloor heating, characteristic of performance - Definitions, method of testing, sizing and formula symbols; German version EN 50559:2013/A1:2020