Design and environment control of closed plant factories with artificial lighting

Closed plant factories with artificial lighting were developed to support suitable environment for high-quality commercial transplant production by using minimum materials, energy and resource consumption. Two pilot closed plant factories using fluorescent lamps as artificial lighting that were similar to plant photosynthetic spectral property, were constructed by opaque thermal insulated materials in China Agricultural University. They were controlled at a suitable physical environment and high cleanness by using recycled ventilation in laminar flow and filtration with polyfiber prefilters and high efficiency particulate air filters. Through two years operation, the cleanness with M7-grade national standard in the closed plant factories was obtained. The environment levels of control point in the floor area of 15 m² for tissue culture were controlled with temperature at (25.4±0.5)℃, (25.3±0.7)℃ and (25.5±0.7)℃, relative humidity at (63±4)%, (65±6)%, and (63±7)%, and CO₂ concentration at (803±13)μL/L as light intensity of the fluorescent lamps at (47±8), (67±12), and (113±21) μmol·m^-2·s^-1, respectively. Therefore, the closed plant factory with artificial lighting as a new-type production pattern with clean and high-efficiency requirement is available in uniform environment and suitable cleanness for high-quality transplant and value-added medical or herb plant production on large scale.