Ventilation and air circulation are vital in controlling temperature and humidity. Plants often grow best in a temperature range of between 18°C and 23°C and in a humidity range of 40%-75%. If you are unable to control these factors, you are likely to experience problems with your plants in terms of disease, lack of acceptable growth, yields and problems associated with various insect pests.
When growing in an enclosed space, it is advisable to use both an extractor fan and an intake fan. An extractor fan will remove the moist (high humidity), warm air as well as other respiratory by-products produced by the leaves. This helps to replenish the carbon dioxide deficient air and reduce plant stress. The size of the extractor fan depends on the size of the growing environment, the number of HID lamps in use and whether carbon filters are being used to help with odour control.
It is recommended that you place an intake fan (in a low position) at the opposite end of the growing environment to the extractor fan (positioned higher up), as it helps to control both the humidity and temperature and introduces carbon dioxide into the environment.
We supply a range of ventilation control equipment, including RAM AIR-PRO Fan Speed Controller, which will control the intake and extractor fans. More complex atmospheric control products are also available, such as, Autogrow Intelliclimate. In a larger growing area, we recommend the use of air circulator fans, which assists in reducing the temperature fluctuations and increases the CO₂ distribution throughout the growing environment.