The CHHC-1 controls all of your growing area conditions accurately & reliably. First of all, it has all of the C02 control features of the CPPM-1. It also has the ability to control 3 other devices, a heating device and a humidity device. This controller is simple to use. You can set separate day and night temperature settings as well as humidity settings. Records the min and max temperature, humidity and C02 levels. Unlike some C02 controllers, the CHHC-1 is able to be calibrated by the user with our "self calibration feature".