Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


osu1274996517.pdf (3.22 MB)

ETD Abstract Container

Abstract Header

Cooling Capacity Assessment of Semi-closed Greenhouses

Lee, Wee Fong
http://rave.ohiolink.edu/etdc/view?acc_num=osu1274996517

Abstract Details

2010, Master of Science, Ohio State University, Food Agricultural and Biological Engineering.
Leading Dutch researchers reported significant benefits to closed greenhouse systems. Ooteghem (2007) simulation studies of optimal control in a closed greenhouse environment predicted 52% heating fuel saving and 39% increase of tomato crop yield using a heat recovery system whose major components included heat pumps, heat exchangers and aquifers. Opdam et al. (2005) reported 19% primary energy saving, 22% yield increase, 80% chemical reduction, and 50% irrigation water saving for tomato production in a closed greenhouse. Although the Dutch researchers successfully demonstrate year-round operation of closed greenhouses, their success benefited from the mild weather and availability of aquifers, not always the case for other geographical regions. Results of this study using Ohio conditions estimated that 90% and 92% of CO2 loss through cooling and dehumidification ventilations when an elevated CO2 level of 800 ppm must be maintained. This study also found that for Wooster, Ohio to achieve economical year-round closure, due to the larger weather variation and lack of accessibility to aquifers, a better economical return would be expected with semi-closed designs that allow the greenhouse to vent when the heat load is approaching a certain percent of peak levels. For example, a 50% peak load design can meet the cooling and dehumidification needs of a closed greenhouse for 92% and 90% of the year, respectively. Also determined in this study was the amount of heat which can be recovered with thermal storage. Potential recoverable heat of a closed greenhouse at Wooster, Ohio can contribute up to 23%, 25% and 98% of total heating needs of the year, 2006, with 1-day, 2-day and year-round thermal storage capacities, respectively. The models used for the above analyses were evaluated using data collected in a greenhouse located at Wooster, OH. Convection and infiltration heat loss prediction were validated during cloudy and clear sky nights. The results gave prediction disagreements of 0.2% to 2% and 30% under cloudy and clear sky conditions, respectively. Also evaluated was the potential recoverable heat from ventilation exhaust. Result showed that ventilation time prediction disagreement were -8.2% and 0.8%, when net solar radiation transmittances were estimated at 0.54 and 0.57, respectively. Although further improvements of this model could be done, the data processing framework established for the heat recovery strategy evaluation is valuable for the assessment of potential benefits of semi-closed greenhouse.
Peter P. Ling, PhD (Advisor)
Harold M. Keener, PhD (Committee Member)
133 p.
Agricultural Engineering; Engineering
Decision support tool; CO2 enrichment; Dehumidification; No-vent; Heat storage; Solar radiation heat recovery; Recycle heat; Growing Season Extension; Cooling; Semi-closed, Greenhouse

Recommended Citations

Citations

  • Lee, W. F. (2010). Cooling Capacity Assessment of Semi-closed Greenhouses [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1274996517

    APA Style (7th edition)

  • Lee, Wee Fong. Cooling Capacity Assessment of Semi-closed Greenhouses. 2010. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1274996517.

    MLA Style (8th edition)

  • Lee, Wee Fong. "Cooling Capacity Assessment of Semi-closed Greenhouses." Master's thesis, Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1274996517

    Chicago Manual of Style (17th edition)

osu1274996517
6,442
© 2010, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.