Why is there airflow but no smoke on my cart?

Excuse me, could you please explain why there seems to be airflow coming from my cart, but no smoke is visible? I'm a bit confused as I expected to see some smoke production given the airflow. Is this a common issue, or could there be a specific reason behind it? Could it be related to the type of product I'm using, or perhaps a technical issue with the cart itself? I'd appreciate any insights you could offer to help me understand this situation better. Thank you.