加拿大国家研究委员会（NRCC）建筑研究所（IRC）开发了一套测试设备和程序，用于确定窗户产品的热特性。对以下类型的嵌装玻璃单元进行了初步工作:-密封双层玻璃，透明玻璃-透明玻璃上涂有低发射率涂层的密封双层玻璃-密封三层玻璃，透明玻璃-带低发射率涂层的薄塑料膜密封三层玻璃-不带垫片的非密封双层玻璃。所有单元均在以下试验条件下进行试验，以确定其耐热性（表面到表面的R值）:-室温:21℃-天气侧温度:-7、-21和-35℃，一些单元也在-14、-18℃下进行试验，和-28℃——整个试样的压差保持在3Pa以下气象侧气流垂直于试样。 根据ASHRAE的建议，还提供了结合表面传热系数的总传热系数（U值），以及为每个试样确定的R值。虽然目前还没有确定密封装置总传热系数（U值）的标准试验程序，但这些试验结果表明了所试验样品的相对性能。将一些试样的实验结果与通过NRCC开发的计算机程序VISION预测的值进行比较，以评估玻璃系统的热性能。单位:SICitation:Symposium，ASHRAE交易，1988年，第94卷，pt。2、渥太华

A test facility and procedures to determine the thermal characteristics of window products were developed at The Institute for Research in Construction (IRC), National Research Council Canada (NRCC). Initial work was conducted on the following types of glazing units:- sealed double-glazed, clear glass- sealed double-glazed with low emissivity coating on clear glass- sealed triple-glazed, clear glass- sealed triple-glazed with thin plastic film with low emissivity coating- unsealed double-glazed without spacerAll units were tested to determine their thermal resistance (surface to surface R-value) at the following test conditions:- room-side temperature: 21°C - weather-side temperature:-7, -21, and -35°C, and some units were also tested at -14, -18, and -28°C.- pressure difference across the test specimen was kept less than 3Pa.- weather-side airflow was perpendicular to specimen.Overall heat transmission coefficients (U-value) are also provided combining the surface heat transfer coefficients, as recommended by ASHRAE, with the R-value determined for each speclmen. Although there is at present no standard test procedure for the determination of the overall coefficient of heat transmission (U-value) sealed units, these test results indicate the relative performance of the samples tested.The experimental results of some of the specimens are compared with values predicted using the computer program VISION developed, through NRCC, to evaluate the thermal performance of glazing systems.Units: SI