由于方位、纬度、月份、太阳辐射、风、室外温度和遮阳等可变因素难以量化和概括，在供暖季节通过窗户获得的太阳能的有益影响通常被忽略在年度住宅热损失的估算中。美国国家标准局（1,2）新墨西哥大学（3）和伊利诺伊大学小住宅理事会（4）最近的研究表明，与北向玻璃相比，定向和净热增益或减少热损失的重要性。后一项研究得出的结论是，太阳能增益可以提供传统家庭18%的供暖需求，以及高隔热家庭35%的供暖需求，最大的太阳能利用率为100%- 面向玻璃。国家统计局的报告基于华盛顿特区的一个地点，小型住宅委员会利用威斯康星州麦迪逊进行了洛卡尔住宅研究。在新墨西哥大学的工作是基于单一和双层玻璃在该州的位置。提出了一种计算中空玻璃热流平衡的简化方法。该方法可以修改和扩展，以包括其他变量，如建筑类型、方向、双层玻璃、三层中空玻璃和吸热玻璃。引文:宾夕法尼亚州费城ASHRAE学报第85卷第1部分研讨会

The beneficial effect of solar gain through windows during the heating season is usually omitted from estimates of yearly residential heat loss, because the variable factors of orientation, latitude, month, solar insolation, wind, outdoor temperature and shading are difficult to quantify and generalize. Recent studies by the National Bureau of Standards (1,2) University of New Mexico (3) and the Small Homes Council (4) at the University of Illinois demonstrate the importance of orientation and the net heat gain or reduced heat loss in comparison with North-facing glazing. The latter study concluded that solar gain could provide 18 percent of the heating requirement in a conventional home and 35 percent of the requirement of a highly insulated home with a maximum of South-facing glazing. The NBS reports are based on a Washington, D. C. location, and the Small Homes Council used Madison, Wisconsin for the Lo-Cal house study. The work at the University of New Mexico is based on single and double glazing for locations in that State.A simplified method of calculating the balance of heat flow through insulating glass has been developed. The methodology can be modified and expanded to include other variables such as building type, orientation, dual glazing, triple insulating glass and heat absorbing glass.