Lighting systems in major New Zealand controlled environment facilities

Abstract The lighting systems used in New Zealand in the Department of Scientific and Industrial Research (DSIR) Climate Laboratory controlled environment rooms, the Forest Research Institute (FRI) tree growth rooms, and the DSIR-designed reach-in controlled environment chambers are described. All lighting systems are based on high-pressure discharge lamps which can be used with varying amounts of incandescent light supplementation. The main lighting type used in the Climate Laboratory controlled environment rooms is the high-pressure metal halide lamp, that in the FRI rooms the high-pressure mercury-vapour fluorescent lamp with internal reflector, and that in the reach-in chambers a high-pressure mercury halide lamp. Details of lighting rig design, of irradiance levels obtainable, vertical and horizontal light distribution patterns and spectral quality are presented for each system. The photosynthetic irradiance levels available at 2–3 m below the lighting systems in all of these controlled environment systems are high (180–200 W m −2 PAR). In the Climate Laboratory and FRI growth rooms peak sunlight values of approximately 400 W m −2 PAR (approximately 10,000 ft.c.) have been achieved. A discussion of the performance of these systems is also presented.