Jong Pil Moon

Analysis of Air Temperature and Humidity Distributions and Energy Consumptions according to Use of Air Circulation Fans in a Single-span Greenhouse

The aim of this study was to compare and analyze air temperature and humidity distribution and energy consumptions according to using air circulation fans in single-span greenhouses. The greenhouses located in Cheongnam-myeon, Cheongyang-gun, Chungcheongnam-do, Korea. There were cherry tomatoes in the greenhouses and the size of greenhouses was as follows;ridge height : 3.2 m, wide : 6 m, length : 95 m. The heating system was composed of a hot-water boiler and 6 FCUs(Fan Coil Unit)-4 FCUs were on bottom with duct and 2 FCUs were installed at 2.0 m. A total of 18 air circulation fans(impeller’s diameter : 230 mm) were bilaterally arranged in 2 rows in the experimental greenhouse. The sensors for measuring air temperature and humidity were located at a quarter and three quarters of a length. The height of sensors were 0.8 m, 1.8 m. To calculate energy consumption in greenhouses, water temperature at inlet and outlet in a water pump, volume of water were measured. Form February 3rd to March 23th, temperature, humidity and energy consumptions were measured during heating time(6pm~7am). In a greenhouse without fans, the average differences of temperature and humidity were 0.75C, 2.31%, respectively. The operation of fans showed their differences to 0.42C, 1.8%. The standard deviation of temperature and humidity between measuring points in the greenhouse with fans was lower than the greenhouse without fans. Total energy consumptions in a greenhouse without fans were 4,673 kWh. In the greenhouse with fans, the total energy consumptions were 4,009 kWh. The energy consumptions in a greenhouse with fans 14.2% were less than the greenhouse without fans. Therefore, air circulation makes temperature and humidity uniform and saves energy consumptions for heating. Additional key words : Air circulation, Energy saving, Environment, Greenhouse

Effect of Growing Part Following Local Heating for Cherry Tomato on Temperature Distribution of Crop and Fuel Consumption

Local heating system providing hot air locally to growing parts including shoot apex and flower cluster which were temperature-sensitive organs of cherry tomato was developed to reduce energy consumption for greenhouse heating without decline of crop growth. Growing part following local heating system was composed of double duct distributer which connected inner and outer ducts with hot air heater and winder which moved ducts up and down following growing parts with plant growth. Growing part local heating system was compared with conventional bottom duct heating system with respect to distributions of air and leaf surface temperatures according to height, growth characteristics and energy consumption. By growing part local heating, air temperature around growing part was maintained 0.9~2.0C higher than that of lower part of crop and leaf surface temperature was also stratified according to height. Investigations on crop growth characteristics and crop yield showed no statistically significant difference except for plant height between bottom duct heating and growing part local heating. As a result, the growing part local heating system consumed 23.7% less heating energy than the bottom duct heating system without decrease of crop yield. Additional

Spot Cooling System Development for Ever-bearing Strawberry by Using Low Density Polyethylene Pipe

Abstract The effects of spot cooling on growing ever-bearing strawberry in hydroponic cultivation during summer by spot cooling system w as estimated in plasticgreenhouse located in Pyeongchang. The temperature of cooling water was controlled by heat pump and maintained at the range of 15~20 ℃. Cooling pipes were installed in root zone and very close to crown. Spot cooling effect was estimated by applying system in three cases which were cooling root zone, crown plus root zone, and crown only. White low density po lyethylene pipe in nominal diamet er of 16 mm was installed on c rown spot, and Stainles ssteel flexible pipe in nominal diameter of 15A was installed in root zone. Crown and root zone cooling water circulation was co ntinuously performed a tflowrates of 300 ~ 600 L/hr all day long. Strawberry yields by test beds were surveyed from Aug. 1 to Sep. 30. The accumulated yield growth rate compare dwith a control bed of crown cooling bed was 25 % and that of crown plus root zone cooling bed was 25 % and that of root zone co oling bed was 20 %. Thetemperatures of root spot in root zone cooling was maintained at 18.0 ~ 23.0 ℃ and that of crown spot in crown cooling was maintained at 19~24 ℃. Also ,the temperatures of root spot in crown plus root zone cooling bed was maintained at 17.0 ~ 22.0 ℃ and that of crown spot was maintained at 19~25 ℃.Keywords: Spot cooling system; Ever-bearing strawberry; Crown cooling; Low density polyethylene pipe*

Development of On-site Heat Loss Audit and Energy Consulting System for Greenhouse

Purpose: Greenhouses for a protected horticulture covered with a plastic or glass are easy to have weakness in a heat loss by deterioration, damage, poor construction, and so on. To grasp t he vulnerable points of heat loss of the greenhouses is important for heating energy saving. In this study, an on-site heat loss audit and energy consulting system were developed for an efficient energy usage of a greenhouse. Method: Developed system was mounted with infrared thermal and visual cameras to grasp the heat loss from the greenhouse quickly and exactly, and a trial calculation program of heating load of greenhouse to provide farmers with the information of heating energy usage. Results: Developed system could print out the reports about the locations and causes of the heat losses and improvement methods made up by an operator. The mounted trial calculation program could print out the information of the period heating load and fuel cost according to the conditions of greenhouse and cultivation. The program also mounted the databases of the information on the 13 horticultural energy saving technologies developed by the Korea Rural Development Administration and simple economic analysis sub-program to predict the payback period of the technologies. Conclusion: The developed system was expected to be used as the basic equipment for an instructors of district Agricultural Technology and Extension Centers to conduct the energy consulting service for the farmers within the jurisdiction.