Particulate Matter and CO₂ Improvement Effects by Vegetation-based Bio-filters and the Indoor Comfort Index Analysis

Abstract

BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for PM 10 and 81 times for PM2.5. Air quality is becoming a serious issue nationwide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in airconditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on airconditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by 1.6℃ and black bulb temperature by 1.0℃. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While PM 10 was reduced by 39.5% to 22.11㎍/m 3 , CO 2 increased up to 1,329ppm. It is interpreted that released CO 2 could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetationbased bio-filter system is effective in lowering indoor temperature and PM 10 and has positive effects on creating comfortable indoor space in terms of PMV and PPD.

A Pilot Study of Improving the Atmospheric Environment of Classroom for Students' Learning Activities

“…Each unit panel has a multilayered structure with three layers of 50-mm filters. In this study, 288 air-purifying plants (24 species), including Hoya carnosa, Ficus elastica, and Epipremnum aureum, selected by Kim et al (2018) were planted. The classroom, in which the system was installed, was finished with a gable roof and had space for 20 seats with a floor area of 52.8 m 2 and a volume of 332.73 m 3 .…”

Removal of Iron Oxide from Indoor Air at a Subway Station Using a Vegetation Biofilter: A Case Study of Seoul, Korea

“…Biofilter systems that increase PM removal efficiency by linking air-purifying plants with air conditioning facilities are drawing attention because they help to overcome the aforementioned challenge. Mechanistically, a biofilter adsorbs gases present in indoor polluted air, following which the gases are decomposed upon passing through base materials such as plants [30]. Soreanu et al (2013) classified biofilters that use plants into passive and active types [31].…”

“…In this study, an active-type vegetation biofilter system was used. Studies have been conducted on the particulate pollutant (arising from diesel fuel combustion) removal efficiency of vegetation biofilters [21]; the effects of vegetation biofilters on PM concentrations, carbon dioxide levels, and indoor comfort indices [30]; and PM removal efficiency of vegetation biofilters in the lecture rooms of universities, which are environments with continuous emissions of particulate pollutants [32]. Vegetation biofilter systems are expected to be useful as an eco-friendly purification method to improve air quality in the future.…”