All Issue

2026 Vol.35, Issue 2 Preview Page

Original Articles

Field Evaluation of Circulation Fan Performance and Microclimate Non-Uniformity in Multi-Layer Vertical Farming Greenhouse

다단 수직형 식물공장 온실에서 순환팬 성능 및 미기후 비균일성의 평가

Nelson Junior Rodillas1†
,
Jaemin Yu1†
,
Seong-Ha Kang1
,
Uk-hyeon Yeo2*
로딜리아스 넬슨 주니어1†
,
유 재민1†
,
강 성하1
,
여 욱현2*
1Graduate Student, Department of Agricultural Engineering, College of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, Korea
2Assistant Professor, Department of Agricultural Engineering, College of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, Korea
1경상국립대학교 농업생명과학대학 농공학과 대학원생
2경상국립대학교 농업생명과학대학 지역시스템공학과 조교수
*Corresponding Author
†These authors contributed equally to this work.
30 April 2026. pp. 126-138
PDF XML Citation
Abstract

Multi-layer vertical farming greenhouses have been increasingly adopted to enhance land-use efficiency and enable year-round crop production. However, dense cultivation racks and crop canopies restrict air movement, potentially leading to spatially non-uniform microclimatic conditions. These non-uniform conditions can lead to localized heat and moisture accumulation, reducing the efficiency of environmental control and resulting in non-uniform crop growth. This study experimentally evaluated fan performance and the non-uniformity of the microclimate in a commercial-scale multi-layer vertical farming greenhouse with 34 cultivation racks and above- and below-mounted circulation fans. Field measurements of fan outlet velocity, air temperature, relative humidity (RH), greenhouse air velocity, and a fan-on/off comparison under fully open window conditions were conducted. The results showed substantial variability in the 10 above-mounted fan outlet velocities (3.23－5.00 m/s), lower outlet velocities observed at 90° turning locations, indicating an imbalanced distribution along the circulation path. The four below-mounted fans showed more consistent outlet velocities (3.43－4.57 m/s), but their spatial coverage was limited because only four were installed across 34 cultivation racks. Indoor air temperature and RH measured at 1.5 m height showed moderate spatial non-uniformity, with coefficients of variation of 6.52% and 7.73%, respectively. Central regions consistently exhibited higher temperatures and lower RH. Greenhouse air velocity measured at sensor locations ranged from 0.08 to 0.21 m/s, indicating spatial variation in local airflow magnitude. Under the tested full-open window condition, fan operation was associated with a slight decrease in mean temperature and small reductions in the spatial variability of temperature and RH, suggesting a modest improvement in internal mixing rather than a substantial homogenization. These results provide field-based experimental data essential for future CFD-based analysis and the improvement of environmental control strategies in a multi-layer vertical farming greenhouse.

Keywords
airflow distribution
microclimate heterogeneity
natural ventilation
ventilation control
vertical farming

다단 수직형 식물공장 온실은 토지 이용 효율을 향상시키고 연중 작물 생산을 가능하게 하기 위한 대안으로 점차 확대되고 있다. 그러나 고밀도 재배 랙과 작물 캐노피는 공기 흐름을 제한하여 공간적으로 비균일한 미기후 조건을 형성할 수 있다. 이러한 비균일성은 국부적인 열 및 수분 축적을 초래하여 환경 제어 효율을 저하시킬 뿐 아니라, 작물 생육의 불균일성을 유발할 수 있다. 본 연구에서는 34개의 재배 랙과 상부 및 하부에 설치된 순환팬을 갖춘 상업 규모의 다단 수직형 식물공장 온실을 대상으로, 팬 성능과 미기후 비균일성을 실험적으로 평가하였다. 팬 출구 유속, 온실 내 공기 유속, 기온, 상대습도(Relative Humidity)에 대한 현장 측정 및 전면창 개방 조건에서 팬 작동(on/off) 비교 실험을 수행하였다. 그 결과, 상부에 설치된 10개 순환팬의 출구 유속(3.23－5.00 m/s)은 변동성이 크게 나타났으며, 특히 90° 전환 구간에서 상대적으로 낮은 유속이 관찰되어 순환 경로를 따라 불균형한 유동 분포가 나타남을 확인하였다. 반면, 하부에 설치된 4개 팬은 보다 일관된 출구 유속(3.43－4.57m/s)을 보였으나, 34개의 재배 랙에 비해 설치 수가 제한적이어서 공간적 커버리지를 확보하지 못한 것으로 나타났다. 지상 1.5m 높이에서 측정된 실내 기온과 상대습도는 각각 변동계수 6.52%와 7.73%로 중간 수준의 공간적 비균일성을 보였으며, 중앙부 영역에서는 지속적으로 더 높은 기온과 더 낮은 상대습도가 나타났다. 센서 위치에서 측정된 온실 내 공기 유속은 0.08－0.21 m/s 범위로 나타났으며, 위치에 따라 국소 기류 세기의 차이가 존재함을 시사한다. 전면 창 개방 조건에서 팬 작동은 평균 기온을 소폭 감소시키고 기온 및 상대습도의 공간적 변동성을 일부 완화하는 경향을 보였다. 이는 완전한 균질화보다는 내부 공기 혼합의 제한적인 개선 효과를 나타내는 것으로 해석된다. 본 연구 결과는 향후 전산유체역학(CFD) 기반 해석 및 다단 수직형 식물공장 온실의 환경 제어 전략 고도화를 위한 기초 실측 자료로 활용될 수 있다.

키워드
기류 분포
미기후 이질성
수직 농업
자연 환기
환기 제어
References
1

Ahmed HA, Yu-xin T, Qi-chang Y (2020) Lettuce plant growth and tipburn occurrence as affected by airflow using a multi-fan system in a plant factory with artificial light. J Therm Biol 88:102496. https://doi.org/10.1016/j.jtherbio.2019.102496

10.1016/j.jtherbio.2019.102496
2

AMCA International (2016) AMCA Standard 210: Laboratory Methods of Testing Fans for Aerodynamic Performance Rating. Air Movement and Control Association International.

3

ASHRAE (2021) ASHRAE Handbook—Fundamentals. American Society of Heating, Refrigerating and Air-Conditioning Engineers.

4

Bournet PE, Boulard T (2010) Effect of ventilator configuration on the distributed climate of greenhouses: A review of experimental and CFD studies. Comput Electron Agric 74: 195-217. https://doi.org/10.1016/j.compag.2010.08.007

10.1016/j.compag.2010.08.007
5

Bojacá CR, Gil R, Gómez S, Cooman A, Schrevens E (2009) Analysis of greenhouse air temperature distribution using geostatistical methods. Trans ASABE 52:957-968. https://doi.org/10.13031/2013.27393

10.13031/2013.27393
6

He K, Chen D, Sun L, Liu Z, Huang Z (2015) The effect of vent openings on the microclimate inside multi-span greenhouses during summer and winter seasons. Eng Appl Comput Fluid Mech 9:399-410. https://doi.org/10.1080/19942060.2015.1061553

10.1080/19942060.2015.1061553
7

Lee SW, Seo IH, An SW, Na HY (2023) Improvement of environmental uniformity in a seedling plant factory with porous panels using computational fluid dynamics. Horticulturae 9:1027. https://doi.org/10.3390/horticulturae9091027

10.3390/horticulturae9091027
8

Lee TS, Kang GC, Paek Y, Moon JP, Oh SS, Kwon JK (2016) Analysis of temperature and humidity distributions according to arrangements of air circulation fans in single-span tomato greenhouse. Prot Hortic Plant Fact 25:277-282. https://doi.org/10.12791/KSBEC.2016.25.4.277

10.12791/KSBEC.2016.25.4.277
9

Lim TG, Kim YH (2014) Analysis of airflow pattern in plant factory with different inlet and outlet locations using computational fluid dynamics. J Biosyst Eng 39:310-317. https://doi.org/10.5307/JBE.2014.39.4.310

10.5307/JBE.2014.39.4.310
10

Majdoubi H, Boulard T, Fatnassi H, Bouirden L (2009) Airflow and microclimate patterns in a one-hectare Canary type greenhouse: An experimental and CFD assisted study. Agric For Meteorol 149:1050-1062. https://doi.org/10.1016/j.agrformet.2009.01.002

10.1016/j.agrformet.2009.01.002
11

Mao Q, Li H, Ji C, Peng Y, Li T (2024) Experimental study of ambient temperature and humidity distribution in large multi-span greenhouse based on different crop heights and ventilation conditions. Appl Therm Eng 248:123176. https://doi.org/10.1016/j.applthermaleng.2024.123176

10.1016/j.applthermaleng.2024.123176
12

Mohd Noh A, Mohd Tahir MA, Shafie KA (2021) Plant factory airflow distribution analysis with different inlet configuration. Adv Agric Food Res J 2(2). https://doi.org/10.36877/aafrj.a0000242

10.36877/aafrj.a0000242
13

Moon SM, Kwon SY, Lim JH (2014) Minimization of temperature ranges between the top and bottom of an air flow controlling device through hybrid control in a plant factory. Sci World J 2014:1-7. https://doi.org/10.1155/2014/801590

10.1155/2014/80159025013867PMC4074998
14

Sarailoo H, Campbell L, Bougherara H (2025) A comprehensive review on the application of computational fluid dynamics in enhancing indoor vertical farm microclimate. J Biosyst Eng 50:145-169. https://doi.org/10.1007/s42853-025-00257-0

10.1007/s42853-025-00257-0
15

Sohn J, Liulys M, Avgoustaki DD, Xydis G (2023) CFD analysis of airflow uniformity in a Shipping-Container vertical farm. Comput Electron Agric 215:108363. https://doi.org/10.1016/j.compag.2023.108363

10.1016/j.compag.2023.108363
16

Sun X, He J, Li C, Chen Y, Li R, Wang Z, Wu W, Li Y, Guo X, Wang X (2023) Field investigation of non-uniform environment in a Venlo-type greenhouse in Yangling, China. Heliyon 9:e22143. https://doi.org/10.1016/j.heliyon.2023.e22143

10.1016/j.heliyon.2023.e2214338034636PMC10685296
17

Wei X, Li B, Lu H, Guo J, Dong Z, Yang F, Lü E, Liu Y (2024) Distribution characteristics and prediction of temperature and relative humidity in a South China greenhouse. Agronomy 14:1580. https://doi.org/10.3390/agronomy14071580

10.3390/agronomy14071580
18

Yu IH, Cho MW, Lee SY, Chun H, Lee IB (2007) Effects of circulation fans on uniformity of meteorological factors in warm air heated greenhouse. J Bio-Environ Control 16: 291-296.

19

Zhang Y, Chen C, Fang H, Tong Y (2025). Improving air distribution within lettuce plant canopy by employing double-channel ventilation cultivation system: Simulation and experiment study. Agronomy 15:2326. https://doi.org/10.3390/agronomy15102326

10.3390/agronomy15102326
20

Zhang Y, Kacira M (2022) Analysis of climate uniformity in indoor plant factory system with computational fluid dynamics (CFD). Biosyst Eng 220:73-86. https://doi.org/10.1016/j.biosystemseng.2022.05.009

10.1016/j.biosystemseng.2022.05.009
21

Zhang Y, Kacira M, An L (2016). A CFD study on improving air flow uniformity in indoor plant factory system. Biosyst Eng 147:193-205. https://doi.org/10.1016/j.biosystemseng.2016.04.012

10.1016/j.biosystemseng.2016.04.012
Information
  • Publisher :The Korean Society for Bio-Environment Control
  • Publisher(Ko) :(사)한국생물환경조절학회
  • Journal Title :Journal of Bio-Environment Control
  • Journal Title(Ko) :생물환경조절학회지
  • Volume : 35
  • No :2
  • Pages :126-138
  • Received Date : 2026-02-04
  • Revised Date : 2026-04-23
  • Accepted Date : 2026-04-28
  • DOI :https://doi.org/10.12791/KSBEC.2026.35.2.126
Journal Informaiton Journal of Bio-Environment Control Journal of Bio-Environment Control
Online Submission
  • NRF
  • KOFST
  • crossref crossmark
  • crossref cited-by
  • crossref funder-registry
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close