Aprilaire 1130 is a humidifier designed for commercial applications that adds moisture to the air in the form of water vapor. It is typically suspended from the ceiling and can be installed with ductwork to distribute the humidified air. The unit features a Water Panel evaporator that should be changed annually to prevent clogging of the element. The Aprilaire 1130 is equipped with a solenoid valve to control the water flow and a motor to circulate the air. It also has a humidistat control circuit that allows it to be connected to a humidistat to maintain a desired humidity level.