For entrepreneurs in the greenhouse horticulture sector it is not only important to reduce CO2 emissions, but naturally also to optimise productivity. Active climate control through ventilation and circulation plays an important role in this. This leads to:
- Reduction in the temperature differential
- Better distribution and absorption of CO2
- Reduction of the risk of moisture-associated diseases such as Botrytis, mildew and Mycosphaerella.
Climate control in the greenhouse can be a major challenge due to variable temperatures and humidity conditions. Externally, it is dependent on the weather, location and season. Internally, for example, the cultivation, the surface area, height of the greenhouse and whether or not screening is applied.
Ideal greenhouse climate
An ideal temperature and humidity ensure that the crop in the greenhouse can grow to its full potential, without being impeded by pests and fungi. In other words, an optimal greenhouse climate ensures a higher yield of high quality, with a positive effect on the operating result.
If the temperature is too high, a plant will 'breathe' faster and glucose (sugars) will be burned, which will then no longer be available for growth. However, too low a temperature can have a negative effect on photosynthesis and thus on the development of the crop.
If the air humidity is too low, there is a chance that nutrients will burn, with the result that the crop will grow more slowly. If the humidity is too high, plants will hardly absorb nutrients and water and become more sensitive to fungi and pests.
In order to achieve the ideal transpiration level at plant level, the air must have exactly the right temperature, humidity and movement.
Mechanical ventilation and circulation is one of the most important ways to control the humidity and temperature in a greenhouse. The correct use of mechanical ventilation, or fans, can thereby ensure:
- Optimal air distribution to prevent vertical temperature differences and therefore uniform growth
- Better manageability of the humidity at plant level
- Reduction of energy costs
- A desired constant low air speed at all levels
A crucial part of active climate control is the correct circulation/ventilation and fan choice, based on your specific situation, such as cultivation, area, greenhouse height, screening, etc. You can read more about this here: “Types of ventilation in horticultural greenhouses”.