Greenhouse Growing Tips Great greenhouse tips and useful information to keep your greenhouse running efficiently. ::Construction Tips ::Garden Tips ::Articles What Size Circulation Fan Do I Need?1. Greenhouse area x 10 = fan cfm. Example: 8′ x 12′ = 96 sq. ft. x 10 = 960 cfm. 2. If your greenhouse if half full of plants, deduct 50% (960 x .5 = 480 cfm). 3. If your greenhouse is very full of plants, add 50% (960 x 1.5 = 1440 cfm). Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *Comment *Name *Email *Website This site uses Akismet to reduce spam. Learn how your comment data is processed.