Abstract
In this report the author investigated the influence of water flow rate and water temperature upon the double roofed greenhouse with spraying of well water between the roofing layers.
1) The ratio of room temperature decrease to ambient temperature decrease was as small as 0.20°C/°C. The ratio became larger when the water flow rate became smaller.
This figure of ordinary greenhouse was usually much larger.
2) The ratio of water temperature decrease to room temperature decrease was about 0.6°C/°C.
3) At lower room temperature, the water flow rate became smaller and the over-all heat transmission coefficient (K) larger.
4) By means of modified heat transfer model, the estimation formula was obtained, showing room temperature as a function of sky temperature, ambient temperature, soil temperature and heat flux emitted from spraying water.
5) The relation between the water flow rate and the room temperature was given as an exponential curve. At the optimum water flow rate range of 6-12 liter/m2hr, the ratio of 1.4-4.5 liter m-2hr-1/°C was obtained.
