The NCSU Phytotron has few operating Percival growth chambers.
Four chambers are double door chambers that have lighting, CO2, temperature (-5 to 60C) control. One chamber that is also a larger double door chamber has lighting and moderate temperature (10 to 40C) control. Two large single door chambers have LED lighting, temperature (-15 to 55C), ultrasonic humidifier & dehumidifier. Two single door chambers, one with lighting, CO2, and temperature control and the other is a high humidity dew chamber that has lighting and temperature control.