Night energy balance in a heated low-cost plastic greenhouse.

Resumen:
This paper analyses the night energy balance of an air-heated greenhouse in mild-winter climatic conditions(Almería, Southeastern Spain). The components of the energy balance of the air volume, soil and cover surfaces were determined in a low-cost plastic structure (parral-type), devoid of crop, under continuous and constant inflow of heat into the inside air at moderate (62 W m2) and at high (134 W m2) heating input. For typical winter weather conditions and heating practices in the Almer?´a region, corresponding to the moderate heating input, the energy balance at the soil–air interface showed that the soil heat flux provided most of the energy to compensate for the radiative ground losses, and only a very small amount of sensible energy, of the same order of magnitude as the residual soil evaporation (<5 Wm2), was exchanged between the air and the soil surface. In the greenhouse air volume, energy losses mainly occurred through air-inner cover convective exchange (50 W m2). At the cover ...[/vc_column_text][vc_row_inner column_margin="default" class="prueba" column_direction="default" column_direction_tablet="default" column_direction_phone="default" text_align="left" row_position="default" row_position_tablet="inherit" row_position_phone="inherit" overflow="visible" pointer_events="all"[/vc_row_inner][/vc_column][/vc_row]