2006 Volume 13 Issue 1 Pages 29-34
On the melting snow system using heated air onto the internal roof of a four-span greenhouse, the maximum melting rate of snow was measured in a field experimentation, and was estimated individually for the forced convection area and the natural convection area. The measured melting rate of snow fluctuated with snowfall. The maximum measured melting rate of snow was 1.6kg・m^<-2>・h^<-1>. However, the estimated melting rate of snow was 2.0kg・m^<-2>・h^<-1>. The amount of heat transfer in the forced convection area was 75% of the total heat. This suggests that optimization of ducts providing heated air onto the internal roof may increase the melting rate of snow. It was shown that the double ducts increased the heat transfer up to 18% compared with the single duct. On the other hand, the heat transfer in the natural convection area was small. Opening the thermal screens to raise the air temperature close to the roof surfaces may not work effectively on the melting performance.
