Environmental Uniformity and Climate Control in Plant Factory with Artificial Lighting” by Dr. Murat Kacira (University of Arizona Controlled Environment Agriculture Center).
Indoor Ag Science Café in April was full of data on climate uniformity, crop productivity as well as energy use in indoor farming, presented by Dr. Murat Kacira. Murat is a professor and the Director of Controlled Environment Agriculture Center at the University of Arizona. The first part was about the importance of designing air distribution system. Good air circulation is important for achieving temperature uniformity within the production system as well as minimizing plant environmental disorder such as tip-burn. Murat’s research team works on optimization of the air distribution design by using a computational engineering approach called CFD – Computational Fluid Dynamics, which can visualize the possible difference in air speed and temperature distribution with different designs. Murat then described a theoretical analysis of energy use of indoor farms located in selected geographical locations (Duluth, Phoenix, Seattle, and Miami). Then he shared a recent study on lettuce productivity and tip-burn incidence under different combinations of CO2 concentration and light intensity (daily light integral) conducted in his research facility at the University of Arizona. According to Murat, CO2 enrichment increased tip-burn incidence at higher DLI. Therefore, 850 ppm CO2 and 11-13 DLI is what he recommends and can achieve the energy use efficiency of 0.062 kg lettuce fresh weight produced per 1 kWh electric power consumption.