Netherlands: Jet Ventilation system further optimized in gerbera cultivation

Gerbera nursery Zuijderwijk and Witzier is one of the first companies in which the jet ventilation system was applied. In the first section, where the system was used, there was insufficient capacity to always work without leaving the screens slightly open. That is because in gerbera cultivation, low night–time temperature is required. This was reflected by the recently completed investigation, led by researcher Peter van Weel (Wageningen UR Greenhouse Horticulture).

Because of the low night temperatures, the difference in absolute humidity between inside and outside is small. There is a relatively large amount of dry air needed from above the screen cloth or from outside to remove moisture from the greenhouse. The following measures have been taken to enlarge the removal of moisture with the Ventilation Jet:

A fan is installed with a significantly higher capacity
Ventilation above the screens will be increased, to ensure that the absolutely moisture above the screens is reduced.
The outlet through a hole in the screen is replaced by a tube avoiding turbulence for the fan.

All these measures will mean that both screens can now remain fully closed and the RH will be reduced to 90%. In addition, the energy consumption can be reduced with an additional 3.5 m3 / m2, which is 23%, compared to the initial situation with the first generation Jet Ventilation. A saving could be made of 9%, which brings the total saving up to 30%. The extra electricity consumption of the fans has already been noted.

Source: Kas als Energiebron