In the present work, a hybrid scheme based on the on–off, PID, and Fuzzy-PI controllers is shown, which was applied to the model of a greenhouse for the control of the vapor pressure deficit inside the greenhouse ($VP{D}_{in}$) through variables for heating and cooling around operating points 0.55 (kPa) and 1.0 (kPa), respectively. The implementation of the hybrid scheme was carried out under the concept of hardware-in-the-loop. The performance tests indicated satisfactory results that can be applied to greenhouses.