The first climatic controllers in greenhouses were started using at the beginning of the 80s. Since then their possibilities have increasing up to a degree of sophistication that covers almost all the imaginable situations that meet in the physics of a greenhouse.

The variables to be controlled in a greenhouse are:

• Air Temperature.
• Relative Humidity.
• CO2 concentration (carbon dioxide).
• Solar Radiation.

The facilities used for the control of these parameters are:

• Heating Installation.
• Ventilation system (passive: windows, forced: fans).
• Humidification Installation.
• CO2 Dosage Installation (propane and natural gas burners).
• Liquefied CO2 gas dosing facilities.
• Thermal screens installations.
• Artificial lighting.

Controllers or automatisms comes to handling these parameters.

REQUIREMENTS:

• For the operation and control of greenhouse climate is required of controllers from different calculations and guidelines that effectively manage the various parameters involved, and facilities related to them.
• The record of the evolution of the various parameters involved must be possible, in view of the adoption of mediated and establishing references and suitable setpoint for more efficient control.
• The paradoxes and contradictions in the control are given in certain cases. While the controllers are made with great foundation and extensive knowledge, the success of these depend largely on our culture which must be monitorized and managed in order to be is integrated into our strategy for climate control through proper development, especially in adverse agroclimatic times (low sunlight, excessive heat, etc.).
• The future trend is to integrate the physics of greenhouse with the measurement of physiological parameters of the crop, plant temperature, photosynthetic rate, etc.