轻型商业建筑是一层和两层建筑，带有成套屋顶HVAC装置，约占美国非住宅建筑存量的50%（建筑数量）。尽管如此，人们对这些成套屋顶装置及其相关管道系统的安装性能知之甚少。这些简单的系统使用与住宅系统类似的管道材料和施工技术（众所周知，住宅系统非常容易泄漏）。本文讨论了一项研究，以表征建筑物，量化管道泄漏，并分析这些类型建筑物中管道系统的性能。这项研究在位于北加利福尼亚州的八座不同建筑中测试了15个系统。所有这些建筑的管道都位于吊顶和屋顶板之间的空腔中。 在这些建筑中，有50%的空腔在功能上位于建筑的空气屏障和隔热层之外。本研究中管道的有效泄漏面积约为加利福尼亚州住宅建筑的2.6倍（轻型商业建筑的ELA25[cm2/m2建筑面积]3.4，而住宅建筑的ELA25[cm2/m2建筑面积]1.3）。本文从供电效率的角度对风管进行了热分析。传导效率测量送风静压箱中输送至送风调节器的可用容量的分数。有效性计算是在登记的基础上进行的，包括一个周期的长度，以及风扇是否始终打开或是否与冷却设备一起循环。66%的系统经常开机- 少于10分钟的循环，导致非稳态运行。单元:SICitation:研讨会，ASHRAE交易，1998年，第104卷，第2部分，多伦多

Light commercial buildings, one- and two-story buildings with packaged rooftop HVAC units, make up approximately 50% (of the number of buildings) of the nonresidential building stock in the U.S. Despite this fact, little is known about the installed performance of these packaged rooftop units and their associated ductwork. These simple systems use similar duct materials and construction techniques as residential systems (which are known to be quite leaky). This paper discusses a study to characterize the buildings, quantify the duct leakage, and analyze the performance of the ductwork in these types of buildings.The study tested 15 systems in eight different buildings located in northern California. All of these buildings had the ducts located in the cavity between the drop ceiling and the roof deck. In 50% of these buildings, this cavity was functionally outside both the building's air and thermal barriers. The effective leakage area of the ducts in this study was approximately 2.6 times that in California residential buildings (ELA25[cm2/m2floor area] 3.4 for light commercial compared to 1.3 for residential).This paper looks at thermal analysis of the ducts from the viewpoint of supply effectiveness. Conduction effectiveness gauges the fraction of the capacity available at the supply-air plenum that is delivered to a supply-air register. Effectiveness calculations are done on a register basis and include the length of a cycle and whether the fan is always on or if it cycles with the cooling equipment. Sixty-six percent of the systems had frequent on-cycles of less than 10 minutes, resulting in non-steady-state operation.Units: SI