Does Grobo need to be vented outside? November 30, 2018 18:45 Updated Follow The Grobo is completely self-contained! That means you don't have to vent anything outdoors. The system has two intake fans and one exhaust fan. Those fans circulate all the air through the unit. Related articles How much does the system cost to maintain? What happens if my power goes out? What is the price of Grobo? Where is Grobo manufactured? Seed Selection Guide Comments 0 comments Please sign in to leave a comment.