美国的国家门窗评级委员会（NFRC）和加拿大的加拿大标准协会（CSA）等组织已经做了大量工作，以制定窗户系统热性能评级的标准化程序。这些程序提供了一种很好的方法来比较一个窗口产品和另一个窗口产品。使用这些评级程序中产生的信息的一个限制是，数据是通过测量或模拟固定窗口大小产生的。为了在建筑能耗计算机模拟中使用这些数据，需要为建筑中使用的实际窗户尺寸提供U系数和太阳热增益系数（SHGC）数据。美国和加拿大通过窗口评级程序提供的窗口标签信息不足以计算特定尺寸的U系数或SHGC值。 使用评级程序提供的最少信息，并做出一些简化假设，将允许近似计算特定尺寸的U系数和SHGC值。这项工作概述了一种确定尺寸比U系数和太阳热增益系数（SHGC）值的简化方法。关键词:1997年，计算，透射率，太阳能热增益，热流，性能，额定值，窗户，双层玻璃，三层玻璃冷却:研讨会，ASHRAE Trans。1997年，第103卷，第一部分

Organisations such as the National Fenestration Rating Council (NFRC) in the United States and the Canadian Standards Association (CSA) in Canada have done a vast amount of work to develop standardised procedures for rating the thermal performance of window systems. These procedures provide an excellent means of comparing one window product to another. One limitation to the use of the information produced in these rating procedures is that the data are produced through measurement or simulation for a fixed window size. To use these data in building energy computer simulations, the U-factor and solar heat gain coefficient (SHGC) data need to be available for the actual window sizes used in a building. The window labelling information provided through the window rating procedures in the US and Canada is not enough to calculate size-specific U-factor or SHGC values. Using minimal information that is provided from the rating procedures and making a few simplifying assumptions will allow for an approximation of the size specific U-factor and SHGC values. The work presented outlines a simplified approach to determining size-specific U-factor and solar heat gain coefficient (SHGC) values.KEYWORDS: year 1997, Calculating, transmittance, solar heat gain, heat flow, performance, rating, windows, double glazing, triple glazing