VARIOUS EFFECTIVE COOLING METHODS FOR PLASTIC PIPE HOUSE CULTIVATION IN SUMMER
In Japan, ventilation, shading, air conditioning and other techniques are used for the countermeasures to the heating of the greenhouse in summer. The mist cooling by evaporation is one of the simple air conditioning and its initial and running cost is rather cheap. It has spread to be the most common air conditioning method. However, there is a problem of the spreading of diseases due to dewy plants, as a result of high relative humidity, so the suitable usage has not been clarified yet for the southwest warm humid district in Japan. Therefore, the objective of this experiment was to find out the effective use of mist cooling at various conditions. When outside temperature exceeded 30°C, in the most popular usual plastic pipe house, the air temperature fell by about 3°C by mist cooling compared with the control of no mist cooling. In the high truss plastic pipe house, around 4°C fell by mist cooling. Furthermore 1 to 2°C descent was possible by using together with the newly developed dehumidifier using triethylene glycol as a desiccant. Thermal insulation film and paint as shading materials were also tested to confirm temperature fall effect. Air temperature for all the shading materials was low, compared with the control PVC except one, and growth of plants increased. However, plants growth was not necessarily linear to the fall in the air temperature.
Inden, H., Togou, Y., Kirimura , M. and Rahman , M.J. (2012). VARIOUS EFFECTIVE COOLING METHODS FOR PLASTIC PIPE HOUSE CULTIVATION IN SUMMER . Acta Hortic. 927, 755-763
high temperature, mist cooling, absorbent dehumidifier, shading film, shading paint