Chapter 11 - Physical environmental factors and their properties

Abstract

A proper understanding of the nature and relationships among the environmental factors in a plant factory with artificial lighting (PFAL) is essential in order to control and maintain the optimum levels of environmental factors to realize the maximum potential of plant production. This chapter describes the physical and chemical properties of the following environmental factors and their measurement: temperature, humidity, CO2 concentration, air current speed, and ventilation rate (number of air exchanges per hour) with regard to the PFAL. In addition, basic concepts of energy balance, radiation, heat conduction, and convection are described in detail. Furthermore, the concept and use of the psychrometric chart are introduced and discussed for their important roles in understanding the environmental control of PFALs.