A greenhouse exhaust fan is a type of ventilation system used in greenhouses to regulate temperature and humidity levels by removing hot and stale air from the structure and replacing it with fresh air. It helps to maintain a healthy growing environment for plants by preventing overheating and excessive humidity, which can lead to plant stress, diseases, and poor growth. Here are some key features and considerations related to greenhouse exhaust fans: Airflow capacity: The fan's airflow capacity, usually measured in cubic feet per minute (CFM), determines how much air it can move within a given time. The appropriate CFM rating depends on the greenhouse size, the number of plants, and the desired air exchange rate. Fan type: Different types of fans can be used in greenhouses, including axial fans and centrifugal fans. Axial fans are commonly used due to their high airflow capacity and relatively low energy consumption. Centrifugal fans are suitable for larger greenhouses or situations where longer ducts are needed. Size and installation: The size of the fan should be chosen based on the greenhouse size and ventilation needs. It should be installed strategically to ensure proper air circulation and minimize dead zones. The fan can be mounted on walls, ceilings, or installed in the end walls or roof. Power source: Greenhouse exhaust fans can be powered by electricity or solar energy, depending on the availability and specific requirements. Solar-powered fans are a sustainable option, especially in off-grid or remote locations.