Sigma Roof Vent

Please note: this window only fits Sigma Greenhouse models. The Planta Sigma Roof Vent is a fantastic add-on for your Sigma Greenhouse. It will efficiently increase air circulation, maintaining a comfortable temperature, which is essential for healthy plant growth and disease control. The number of suggested windows is determined by the size of the greenhouse, the environment and growing zone in which you live, and the plants you would like to cultivate. However, the following numbers are a general guideline: Sigma Urban (10x13): 2-4 windows Sigma 20 (10x19.5): 4-6 windows Sigma 26 (10x26): 6 windows Sigma 32 (10x32): 6-8 windows We recommend installing an even number of roof vents on either side of the greenhouse for optimum airflow.