Semi-Closed Greenhouse (SCG) is working on a “positive” atmospheric pressure principle of between 10-20 psc. The positive pressure allowing much higher micro-climate uniformity and sanitation / plant protection.
The main difference between traditional greenhouse and a SCG is the control of atmospheric pressure.
Traditional greenhouses that are uses “active” ventilation will mostly be under pressure of 15-30 psc. This under pressure is being used as the driving force for air exchanges. The method is a pretty effective for air exchange but have number of notable disadvantages:
- The under pressure creates micro-climate horizontal gradient.This gradient is limiting the systems to relatively short gutters (up to 40 meters).
- The under pressure “helps/draws” the pests in and significantly damages the level of plant protection within the growing area.
- The energy efficiency, especially during times where heating is needed, is significantly lower.