SOLAR STORAGE WALL UTILIZATION FOR POLYETHYLENE GREENHOUSES AS A PASSIVE HEATING SYSTEM

Trials were carried out to overcome the greenhouse air temperature drop within the cold nights of winter season, which affects the greenhouse crop production. Two different cheap materials of adobe and red brick were used as solar storage walls inside gable-uneven span type greenhouses. The greenhouses that comprised storage walls were compared with a control trial greenhouse without storing wall. Consequently the control greenhouse was compared with an open field testing. Soil covers were appliedto study the effect of mulching on the soil heating under the effect of the solar storage wall presence. Crop residues of 5 cm thick, black plastic mulch of 0.2 mm thick were compared with the bare soil without covers.
Investigations were carried out through the period from 30^th November 2004 till 22^nd of February 2005. Effect of warming up the interior microclimate and soil of the greenhouses on the squash crop (Nile variety) production was examined. The following points were considered in the study: effect of the presence of the storage wall on the soil depth temperature, the storage wall thermal efficiency, crop production for each cultivation system and cost estimation
It was found that, squash seeds germination, plants length, number of flowers for each plant squash crop production and the dry weight inside the greenhouse with storage wall trial were greater than that inside the control one with and the open field test. The Trombe wall increased the inside air temperature by 2.2 ^oC and 2.6 ^oC above that without storage wall when using the Trombe wall of adobe and red brick, respectively.