An Experimental Study of New Range-Hood Performance Metrics to Support Energy Savings and Standard/Certification Development
Abstract
In this dissertation, a test facility for measuring capture efficiency (CE) of residential range hoods was built and used to conduct experiments investigating the effects of multiple test factors (e.g. cook-top temperature, mounting height and discharge orientation) on CE as well as its repeatability, reproducibility and variability. The test facility described herein is the first built from the ground up following guidelines specified by a newly developed standard (ASTM-E3087.18), with one other test facility existing in the open literature that was built prior to and then used to develop ASTME3087.18. Although, ASTM-E3087.18 provides a standard method for measuring method for CE, there are no ASHRAE/HVI standard/certification procedures for minimum/allowable range hood CE requirements.
Three performance metrics were developed to describe CE repeatability (ΔCE) and reproducibility (α and β), with ΔCE emphasizing back-to-back tests, while α/β involve a mandatory dismount/re-mount between tests. Results showed that dismounting/remounting a range hood provides a more accurate representation of CE as indicated by the narrower range of values for the reproducibility metrics (α/β) of 0-4.9%CE (max.) versus the repeatability metric (ΔCE), which showed a range of 0-5.6%CE. An adapted test procedure where CE is monitored until the 10 measurements specified by ASTME3087.18 vary by less than 1.5%CE was found to reduce CE uncertainty and improve repeatability/variability. The variability (ε), which is a measure of the standard deviation relative to the mean, was less than 3.5% for all tests utilizing the modified test procedure except cases with a low mounting height and re-circulating vents on the range hood creating leakage.
Other results for CE and its repeatability/variability, showed cook-top temperature had a significant effect on CE, changing it by as much as 9.2%CE, with some range hoods showing CE increasing with temperature and others showing a decrease. However, even at temperatures outside those previously prescribed by ASTM-E3087.18 (i.e.130˚C), the repeatability/variability was unaffected by cook-top temperature. Mounting height also had a significant effect on CE, with lower heights increasing CE and reducing uncertainty, by as much as 7.9%CE and 0.5%CE, respectively, at the expense of worsened variability performance. It is recommended that future ASHRAE/HVI test standards continuously monitor CE, specify cabinet dimensions from the counter-top and require sealing of re-circulation vents. Additionally, it is recommended that future certification tests incorporate a mandatory dismount/remount and specify an intermediate mounting height.
Subject
Capture EfficiencyRange Hood
Kitchen Ventilation
Indoor Air Quality
Test Standards
Energy Efficiency
Citation
Meleika, Sammy (2020). An Experimental Study of New Range-Hood Performance Metrics to Support Energy Savings and Standard/Certification Development. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /191774.