Thermal modelling of a passive style net-zero greenhouse in Alberta: The effect of ground parameters and the solar to air fraction

Agricultural greenhouses can provide a suitable microclimate for crops to thrive under extreme weather conditions. The operations of these greenhouses are expensive due to the energy requirement of the active thermal conditioning systems required to maintain the growing environment for crop production. Engineering of these greenhouses to utilize clean renewable energy sources is critical and necessary to mitigate their carbon footprint, paving the way to a more sustainable agricultural industry. This paper presents numerical modelling of a net-zero passive solar greenhouse in Alberta, Canada with winter temperatures below freezing. The indoor microclimate of the greenhouse is modelled using the detailed radiation model of a transient simulation tool, TRNSYS. The paper investigates the effects of ground parameters and the solar-to-air fraction on the numerical results. The paper includes a cost comparison between crop production in the traditional and passive style greenhouse.