A lot of attention must be paid to optimal greenhouse ventilation when planning the construction. Proper ventilation means that a self-built plant house can never have too many windows. Poor ventilation not only harms plant he alth, it also significantly reduces the harvest.
How do I achieve optimal greenhouse ventilation?
Optimal greenhouse ventilation should allow air to be exchanged 20 to 50 times per hour and allow at least 25% of the floor area to be open. Sufficient windows, hatches, doors and technical devices such as fans must be planned for this.
Ventilation and continuous air circulation are two particularly important factors when growing plants under glass or foil. In commercial vegetable and crop cultivation, the aim is for greenhouse ventilation that enables20 to 50 air exchanges per hour. Recreational gardeners rarely achieve such peak values, and not even if they ventilate properly.
Proper ventilation is not only important in summer
Even in winter, the interior temperatures in greenhouses can rise to undesirable, high-summer values that must be regulated by effective greenhouse ventilation. The air exchange in the greenhouse essentially takes place via:
- Windows and additional hatches or ventilation slots:
- Doors (if possible one on each gable end);
- additional technical devices for ventilation and air circulation (collectors, automatic ventilation systems and fans);
Basic equipment for prefabricated houses is more than poor
In practice and when it comes to proper ventilation, the self-built greenhouse shows all its trump cards. If you consider that many prefabricated house sets in the mid-price segment only contain one or two ventilation windows, it becomes very clear that the growing success for most greenhouse plants will remain well below expectations. Professional growers recommendthat at least 25 percent of the floor area of greenhouses should be able to be opened using suitable devices if proper ventilation is actually important.
Plan greenhouse ventilation generously
Putting additional ventilation windows in the roof after final assembly is very difficult for technological reasons. Therefore, as many windows should be planned in advance as the structural statics and type of construction allow. For optimal greenhouse ventilation, every second window must be positioned so that it can be opened and closed in the opposite direction. On greenhouses that are free-standing and exposed to strong winds, it is best to install the windows so that they can all be opened in the lee.
Jalousie or ventilation windows instead of glass panes
The advantage of this greenhouse ventilation is obvious: These practical ventilation windows have small, movable glass slats that can beangled manually or automatically so that additional air flows in. The disadvantage: You can only get the slats completely tight in winter if the mini windows are covered with additional bubble film.
Tip
In extreme temperatures, greenhouse ventilation helps if a draft can be created at least for a short period of time. An additional window on the gable wall opposite the door is a particularly practical solution.
