Reducing condensation in your greenhouse is a critical step in preventing plant diseases. Condensation occurs when moisture in the warm air condenses on cool leafs and the structure's surfaces. Once this happens, pathogens begin to grow and infect the plants. Fortunately, there are several things you can do to get rid of condensation in your greenhouse.
Install a bottom or between-row heating system in your greenhouse. Common types of bottom and between-row heating systems include pipe heating, bench heating and air heating (forced air heaters). The idea is to use the heating system to keep the temperature of leaf surfaces above the dew point, thus preventing condensation. Installation varies depending on the specific heating system you choose. Follow the manufacturer's directions.
Install thermal screens, which are similar to thermal windows and serve as insulation, preventing warm air inside the greenhouse from coming into contact with cold air outside the greenhouse and creating condensation. Some thermal screens can simply be placed over the existing screen. Others involve an entire system, which must replace the existing screen. Thermal screens can be purchased at some garden supply stores and online horticultural supply centres. Follow the manufacturers directions.
Increase air circulation. Circulating air helps prevent formation of a saturated boundary layer around plant leaves, thus preventing condensation. Run a horizontal air flow (HAF) fan.