In this study a test procedure for determining capture efficiency (CE) of domestic range hoods, namely ASTM-E3087.18, was used to investigate how changing the exhaust orientation of residential range hoods influences CE. Previous studies on residential range hood CE only utilized vertical discharge orientation and do not strictly adhere to ASTM-E3087.18. Furthermore, many range hoods are installed in households using horizontal discharge. In the study reported herein, testing was performed on five range hoods of similar design using both vertical and horizontal exhaust orientations and at a fixed mounting height. Resulting CE values ranged from 50.9 to 94.1%CE with CE varying by as much as 10.6%CE and uncertainty (δ) varying less than 1.0%CE when changing discharge orientation for a specific case. No consistent trend was observed among all range hoods when changing from vertical to horizontal orientation with 30% of cases showing an increase in CE, 30% showing a decrease and 40% showing no change. Exhaust orientation was found not to have a significant influence on CE uncertainty, but had varying effects on repeatability, reproducibility and variability. Additionally, inconsistent exhaust duct design, which may lead to the development of “CO₂ Pockets,” can result in worsened variability performance when comparing exhaust orientations.

在这项研究中，用于确定家用抽油烟机捕获效率 (CE) 的测试程序，即 ASTM-E3087.18，用于研究住宅抽油烟机排气方向的变化如何影响 CE。以前对住宅抽油烟机 CE 的研究仅利用垂直排放方向，并没有严格遵守 ASTM-E3087.18。此外，许多抽油烟机安装在使用水平排放的家庭中。在本文报告的研究中，使用垂直和水平排气方向并在固定安装高度对五个类似设计的抽油烟机进行了测试。产生的 CE 值范围为 50.9 至 94.1%CE，在特定情况下改变排放方向时，CE 变化高达 10.6%CE，不确定性 (δ) 变化小于 1.0%CE。当从垂直方向变为水平方向时，所有抽油烟机都没有观察到一致的趋势，30% 的案例显示 CE 增加，30% 显示减少，40% 显示没有变化。发现排气方向对 CE 不确定性没有显着影响，但对重复性、再现性和可变性有不同的影响。此外，不一致的排气管设计，可能会导致“CO₂ Pockets”，在比较排气方向时会导致可变性性能变差。