Three submersible pumps 560A, 560B, and 560C may be disposed within the fluid storage tank 500 to pump fluid coolant 800 through three corresponding piping subsystems, namely, the coolant circuit 570 (also referred to in FIG. 9A as a “l(fā)ighting loop”), a heating loop 512, and a cooling loop 514. The lighting loop 570 associated with the pump 560A is responsible for providing relatively cooler fluid coolant from the fluid storage tank 500 to one or more lighting fixtures 1000 (e.g., via the coolant circuit 570 as shown in FIGS. 3 and 4) and returning relatively hotter fluid coolant 800 from the one or more lighting fixtures 1000 to the fluid storage tank 500. In this manner, the lighting loop 570 may function as a heat source to heat fluid coolant 800 stored in the fluid storage tank 500 with heat being subsequently distributed to other piping subsystems. In some implementations, the lighting loop 570 may be used to heat at least a portion of the controlled agricultural environment 2000C via natural convection or thermal radiation to regulate and maintain temperature of the portion within a desired temperature envelope.
